*,:before,:after{--tw-border-spacing-x: 0;--tw-border-spacing-y: 0;--tw-translate-x: 0;--tw-translate-y: 0;--tw-rotate: 0;--tw-skew-x: 0;--tw-skew-y: 0;--tw-scale-x: 1;--tw-scale-y: 1;--tw-pan-x: ;--tw-pan-y: ;--tw-pinch-zoom: ;--tw-scroll-snap-strictness: proximity;--tw-gradient-from-position: ;--tw-gradient-via-position: ;--tw-gradient-to-position: ;--tw-ordinal: ;--tw-slashed-zero: ;--tw-numeric-figure: ;--tw-numeric-spacing: ;--tw-numeric-fraction: ;--tw-ring-inset: ;--tw-ring-offset-width: 0px;--tw-ring-offset-color: #fff;--tw-ring-color: rgb(59 130 246 / .5);--tw-ring-offset-shadow: 0 0 #0000;--tw-ring-shadow: 0 0 #0000;--tw-shadow: 0 0 #0000;--tw-shadow-colored: 0 0 #0000;--tw-blur: ;--tw-brightness: ;--tw-contrast: ;--tw-grayscale: ;--tw-hue-rotate: ;--tw-invert: ;--tw-saturate: ;--tw-sepia: ;--tw-drop-shadow: ;--tw-backdrop-blur: ;--tw-backdrop-brightness: ;--tw-backdrop-contrast: ;--tw-backdrop-grayscale: ;--tw-backdrop-hue-rotate: ;--tw-backdrop-invert: ;--tw-backdrop-opacity: ;--tw-backdrop-saturate: ;--tw-backdrop-sepia: ;--tw-contain-size: ;--tw-contain-layout: ;--tw-contain-paint: ;--tw-contain-style: }::backdrop{--tw-border-spacing-x: 0;--tw-border-spacing-y: 0;--tw-translate-x: 0;--tw-translate-y: 0;--tw-rotate: 0;--tw-skew-x: 0;--tw-skew-y: 0;--tw-scale-x: 1;--tw-scale-y: 1;--tw-pan-x: ;--tw-pan-y: ;--tw-pinch-zoom: ;--tw-scroll-snap-strictness: proximity;--tw-gradient-from-position: ;--tw-gradient-via-position: ;--tw-gradient-to-position: ;--tw-ordinal: ;--tw-slashed-zero: ;--tw-numeric-figure: ;--tw-numeric-spacing: ;--tw-numeric-fraction: ;--tw-ring-inset: ;--tw-ring-offset-width: 0px;--tw-ring-offset-color: #fff;--tw-ring-color: rgb(59 130 246 / .5);--tw-ring-offset-shadow: 0 0 #0000;--tw-ring-shadow: 0 0 #0000;--tw-shadow: 0 0 #0000;--tw-shadow-colored: 0 0 #0000;--tw-blur: ;--tw-brightness: ;--tw-contrast: ;--tw-grayscale: ;--tw-hue-rotate: ;--tw-invert: ;--tw-saturate: ;--tw-sepia: ;--tw-drop-shadow: ;--tw-backdrop-blur: ;--tw-backdrop-brightness: ;--tw-backdrop-contrast: ;--tw-backdrop-grayscale: ;--tw-backdrop-hue-rotate: ;--tw-backdrop-invert: ;--tw-backdrop-opacity: ;--tw-backdrop-saturate: ;--tw-backdrop-sepia: ;--tw-contain-size: ;--tw-contain-layout: ;--tw-contain-paint: ;--tw-contain-style: }*,:before,:after{box-sizing:border-box;border-width:0;border-style:solid;border-color:#e5e7eb}:before,:after{--tw-content: ""}html,:host{line-height:1.5;-webkit-text-size-adjust:100%;-moz-tab-size:4;-o-tab-size:4;tab-size:4;font-family:Nunito,ui-rounded,system-ui,sans-serif;font-feature-settings:normal;font-variation-settings:normal;-webkit-tap-highlight-color:transparent}body{margin:0;line-height:inherit}hr{height:0;color:inherit;border-top-width:1px}abbr:where([title]){-webkit-text-decoration:underline dotted;text-decoration:underline dotted}h1,h2,h3,h4,h5,h6{font-size:inherit;font-weight:inherit}a{color:inherit;text-decoration:inherit}b,strong{font-weight:bolder}code,kbd,samp,pre{font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,Liberation Mono,Courier New,monospace;font-feature-settings:normal;font-variation-settings:normal;font-size:1em}small{font-size:80%}sub,sup{font-size:75%;line-height:0;position:relative;vertical-align:baseline}sub{bottom:-.25em}sup{top:-.5em}table{text-indent:0;border-color:inherit;border-collapse:collapse}button,input,optgroup,select,textarea{font-family:inherit;font-feature-settings:inherit;font-variation-settings:inherit;font-size:100%;font-weight:inherit;line-height:inherit;letter-spacing:inherit;color:inherit;margin:0;padding:0}button,select{text-transform:none}button,input:where([type=button]),input:where([type=reset]),input:where([type=submit]){-webkit-appearance:button;background-color:transparent;background-image:none}:-moz-focusring{outline:auto}:-moz-ui-invalid{box-shadow:none}progress{vertical-align:baseline}::-webkit-inner-spin-button,::-webkit-outer-spin-button{height:auto}[type=search]{-webkit-appearance:textfield;outline-offset:-2px}::-webkit-search-decoration{-webkit-appearance:none}::-webkit-file-upload-button{-webkit-appearance:button;font:inherit}summary{display:list-item}blockquote,dl,dd,h1,h2,h3,h4,h5,h6,hr,figure,p,pre{margin:0}fieldset{margin:0;padding:0}legend{padding:0}ol,ul,menu{list-style:none;margin:0;padding:0}dialog{padding:0}textarea{resize:vertical}input::-moz-placeholder,textarea::-moz-placeholder{opacity:1;color:#9ca3af}input::placeholder,textarea::placeholder{opacity:1;color:#9ca3af}button,[role=button]{cursor:pointer}:disabled{cursor:default}img,svg,video,canvas,audio,iframe,embed,object{display:block;vertical-align:middle}img,video{max-width:100%;height:auto}[hidden]:where(:not([hidden=until-found])){display:none}.container{width:100%}@media(min-width:640px){.container{max-width:640px}}@media(min-width:768px){.container{max-width:768px}}@media(min-width:1024px){.container{max-width:1024px}}@media(min-width:1280px){.container{max-width:1280px}}@media(min-width:1536px){.container{max-width:1536px}}.visible{visibility:visible}.invisible{visibility:hidden}.collapse{visibility:collapse}.static{position:static}.fixed{position:fixed}.relative{position:relative}.table{display:table}.transform{transform:translate(var(--tw-translate-x),var(--tw-translate-y)) rotate(var(--tw-rotate)) skew(var(--tw-skew-x)) skewY(var(--tw-skew-y)) scaleX(var(--tw-scale-x)) scaleY(var(--tw-scale-y))}.ring{--tw-ring-offset-shadow: var(--tw-ring-inset) 0 0 0 var(--tw-ring-offset-width) var(--tw-ring-offset-color);--tw-ring-shadow: var(--tw-ring-inset) 0 0 0 calc(3px + var(--tw-ring-offset-width)) var(--tw-ring-color);box-shadow:var(--tw-ring-offset-shadow),var(--tw-ring-shadow),var(--tw-shadow, 0 0 #0000)}.blur{--tw-blur: blur(8px);filter:var(--tw-blur) var(--tw-brightness) var(--tw-contrast) var(--tw-grayscale) var(--tw-hue-rotate) var(--tw-invert) var(--tw-saturate) var(--tw-sepia) var(--tw-drop-shadow)}.filter{filter:var(--tw-blur) var(--tw-brightness) var(--tw-contrast) var(--tw-grayscale) var(--tw-hue-rotate) var(--tw-invert) var(--tw-saturate) var(--tw-sepia) var(--tw-drop-shadow)}.transition{transition-property:color,background-color,border-color,text-decoration-color,fill,stroke,opacity,box-shadow,transform,filter,backdrop-filter;transition-timing-function:cubic-bezier(.4,0,.2,1);transition-duration:.15s}:root{color:#162922;background:#f7fbf8;font-family:Nunito,ui-rounded,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;font-synthesis:none;text-rendering:optimizeLegibility;--ink: #162922;--muted: #60766d;--line: #dce9e2;--mint: #e4ffef;--leaf: #147a55;--panel: #ffffff;--space-1: 4px;--space-2: 8px;--space-3: 12px;--space-4: 16px;--space-5: 24px;--space-6: 32px;--space-7: 48px;--space-8: 64px;--space-9: 96px;--page-gutter: clamp(24px, 3vw, 48px);--section-gap: clamp(24px, 3vw, 40px);--panel-pad: clamp(24px, 2.4vw, 34px);--panel-radius: 26px}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;min-width:320px;min-height:100vh;background:#f7fbf8}button,input,select{font:inherit}button{color:inherit}button:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid rgba(20,122,85,.24);outline-offset:2px}button:disabled{cursor:not-allowed;opacity:.48}.app-shell{min-height:100vh}.skip-link{position:fixed;left:12px;top:10px;z-index:1000;transform:translateY(-160%);padding:10px 14px;border-radius:9px;background:#162922;color:#fff;font-weight:850;text-decoration:none}.skip-link:focus{transform:translateY(0)}.section-shell{width:min(1400px,calc(100% - 48px));margin-inline:auto}.site-header{height:74px;background:#fffffff5;border-bottom:1px solid #e5eee9;position:sticky;top:0;z-index:50}.header-inner{height:100%;display:flex;align-items:center;justify-content:space-between;gap:24px}.brand{border:0;background:transparent;display:flex;align-items:center;gap:10px;padding:0;cursor:pointer;font-family:Manrope,system-ui,sans-serif;font-weight:850;font-size:20px;letter-spacing:-.7px;white-space:nowrap}.brand>span:last-child>span{color:#147a55}.brand-mark{width:39px;height:39px;display:grid;place-items:center;border-radius:13px;background:#b9f46e;color:#234912;transform:rotate(-3deg)}.header-nav{display:flex;align-items:center;gap:4px}.header-nav button{border:0;background:transparent;border-radius:12px;padding:10px 14px;font-weight:750;font-size:14px;color:#52665e;cursor:pointer;display:flex;align-items:center;gap:7px}.header-nav button:hover,.header-nav button.active{background:#e4ffef;color:#126746}.header-actions{display:flex;align-items:center;gap:10px}.lab-badge{padding:9px 13px;border-radius:999px;background:#e4ffef;color:#126746;font-weight:800;font-size:13px;display:flex;align-items:center;gap:7px}.icon-button{width:39px;height:39px;border-radius:12px;border:1px solid var(--line);background:#fff;display:grid;place-items:center;cursor:pointer}.menu-button{display:none}.tool-error{margin:28px 0;padding:clamp(28px,5vw,60px);border:1px solid #e7cfc9;border-radius:22px;background:#fff8f6;text-align:center}.tool-error>svg{width:46px;height:46px;color:#a54a3b}.tool-error h1{margin:5px auto 12px;max-width:650px}.tool-error>p:not(.eyebrow){max-width:680px;margin:0 auto 22px;color:#60766d;line-height:1.55}.tool-error>div{display:flex;justify-content:center;gap:10px}.hero{min-height:540px;margin-top:26px;border-radius:34px;background:#e4ffef;overflow:hidden;display:grid;grid-template-columns:1.08fr .92fr;align-items:center;padding:72px clamp(34px,7vw,100px);position:relative;border:1px solid #d1f0df}.hero-copy{position:relative;z-index:3;max-width:650px}.kicker{width:-moz-fit-content;width:fit-content;padding:8px 12px;border-radius:999px;background:#b9f46e;color:#254e1b;display:flex;align-items:center;gap:7px;text-transform:uppercase;letter-spacing:1px;font-size:11px;font-weight:900}.hero h1{margin:20px 0 18px;font-family:Manrope,system-ui,sans-serif;font-size:clamp(52px,6vw,86px);line-height:.97;letter-spacing:-5px;font-weight:900}.hero h1 span{color:#147a55}.hero-copy>p{font-size:clamp(17px,1.4vw,21px);line-height:1.55;color:#506b60;max-width:590px;margin:0 0 30px}.primary-button{border:0;border-radius:14px;padding:13px 18px;background:#162922;color:#fff;font-weight:850;cursor:pointer;display:inline-flex;align-items:center;justify-content:center;gap:10px;box-shadow:0 8px 20px #1629221f;transition:transform .2s,background .2s}.primary-button:hover{background:#147a55;transform:translateY(-1px)}.primary-button.full{width:100%}.hero .primary-button{padding:15px 20px}.hero-visual{min-height:390px;position:relative;display:grid;place-items:center}.hero-nucleus{width:160px;height:160px;border-radius:50%;background:#ff806d;box-shadow:inset -18px -18px #742a2421,inset 10px 9px #ffffff47,0 20px 60px #ff806d4d;display:grid;place-items:center;position:relative;z-index:2}.hero-nucleus span{font-size:72px;font-weight:300;color:#782f25;line-height:1}.orbit{position:absolute;width:420px;height:160px;border:2px solid rgba(20,122,85,.44);border-radius:50%;transform:rotate(20deg)}.orbit-b{transform:rotate(-48deg);width:380px;height:175px}.orbit i{width:21px;height:21px;position:absolute;border-radius:50%;background:#147a55;top:13px;right:63px;box-shadow:0 0 0 8px #147a551a;animation:electronPulse 2.2s ease-in-out infinite}.orbit-b i{left:45px;top:106px;background:#3a77c5}@keyframes electronPulse{50%{transform:scale(.72);opacity:.75}}.float-chip{position:absolute;padding:10px 13px;border:1px solid rgba(22,41,34,.12);border-radius:14px;background:#fff;box-shadow:0 14px 34px #1629221a;display:flex;align-items:center;gap:8px;font-weight:900;z-index:4;animation:floatChip 3s ease-in-out infinite}.chip-one{left:5%;top:12%;color:#3d68ad}.chip-two{right:1%;top:24%;color:#8a5a04;animation-delay:.6s}.chip-three{right:7%;bottom:11%;color:#147a55;animation-delay:1.1s}@keyframes floatChip{50%{transform:translateY(-8px) rotate(1deg)}}.explorer-section{padding-block:86px 60px}.section-heading{display:flex;align-items:end;justify-content:space-between;gap:20px;margin-bottom:25px}.eyebrow{margin:0 0 7px;text-transform:uppercase;letter-spacing:1.2px;font-size:11px!important;line-height:1.3!important;font-weight:950;color:#147a55!important}.section-heading h2,.tool-card h3,.tool-intro h1,.panel h2,.fact-card h3,.explain-panel h2{font-family:Manrope,system-ui,sans-serif;letter-spacing:-.8px}.section-heading h2{margin:0;font-size:clamp(30px,3vw,44px);letter-spacing:-2px}.result-count{color:#657a71;font-size:14px;font-weight:750}.filter-bar{display:flex;align-items:center;justify-content:space-between;gap:18px;margin-bottom:28px}.search-box{min-width:300px;height:46px;padding:0 14px;display:flex;align-items:center;gap:9px;background:#fff;border:1px solid #dbe7e1;border-radius:14px;color:#6b7d76}.search-box input{width:100%;border:0;outline:0;background:transparent;color:var(--ink)}.search-box.compact{min-width:220px;height:42px}.grade-pills{display:flex;align-items:center;gap:7px;flex-wrap:wrap}.grade-pills button{border:1px solid #dae6e0;background:#fff;color:#597067;border-radius:999px;padding:9px 13px;font-size:13px;font-weight:800;cursor:pointer}.grade-pills button:hover,.grade-pills button.active{border-color:#147a55;background:#147a55;color:#fff}.tool-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}.tool-card{display:flex;flex-direction:column;text-align:left;padding:0;border:1px solid #dfe9e4;border-radius:24px;overflow:hidden;background:#fff;cursor:pointer;box-shadow:0 10px 28px #1629220e}.tool-card:hover{box-shadow:0 18px 46px #1629221c;border-color:#c9ddd3}.tool-art{height:160px;position:relative;overflow:hidden}.tool-icon{width:68px;height:68px;display:grid;place-items:center;background:#ffffffb8;border:1px solid rgba(255,255,255,.85);border-radius:21px;position:absolute;left:24px;top:24px;z-index:2;transform:rotate(-3deg)}.art-bubble{position:absolute;border-radius:50%;border:13px solid rgba(255,255,255,.38);width:96px;height:96px;right:22px;top:17px}.bubble-two{width:40px;height:40px;border-width:7px;right:99px;top:97px}.art-line{width:135px;height:2px;background:#1629222e;position:absolute;right:-18px;bottom:34px;transform:rotate(-22deg)}.tool-card-body{padding:23px 24px 19px;flex:1;display:flex;flex-direction:column}.tool-card h3{font-size:23px;margin:0 0 8px}.tool-card-body>p:not(.eyebrow){margin:0;color:#65766f;line-height:1.55;font-size:14px;flex:1}.card-meta{display:flex;justify-content:space-between;gap:10px;border-top:1px solid #edf2ef;margin-top:20px;padding-top:13px;font-size:11px;text-transform:uppercase;letter-spacing:.5px;color:#70837b;font-weight:900}.empty-state{padding:70px 20px;border:1px dashed #bbccc4;background:#fff;border-radius:24px;text-align:center}.empty-state svg{color:#147a55}.empty-state h3{margin:12px 0 5px}.empty-state p{margin:0 0 16px;color:var(--muted)}.empty-state button{border:0;color:#147a55;font-weight:900;background:transparent;cursor:pointer}.science-note{margin-top:12px;margin-bottom:80px;padding:26px 30px;border-radius:20px;border:1px solid #cbe7d8;background:#e4ffef;display:flex;align-items:center;gap:18px}.science-note>div{min-width:48px;height:48px;display:grid;place-items:center;border-radius:15px;background:#b9f46e;color:#2b5a17}.science-note p{margin:0;line-height:1.55;color:#4c685c}.science-note strong{color:var(--ink)}.site-footer{border-top:1px solid #dfe9e4;background:#fff;padding:28px 0;color:#6a7d75;font-size:13px}.footer-inner{display:flex;align-items:center;justify-content:space-between;gap:20px}.brand.small{font-size:16px;cursor:default}.brand.small .brand-mark{width:32px;height:32px;border-radius:10px}kbd{background:#eef4f0;border:1px solid #d4e0da;box-shadow:0 2px #c6d4cd;padding:2px 7px;border-radius:6px;color:#395349}.tool-page{min-height:80vh;padding-top:22px;padding-bottom:90px}.tool-loading{min-height:420px;display:grid;place-items:center;align-content:center;gap:12px;color:#587066;font-weight:850}.tool-loading span{width:36px;height:36px;border:4px solid #d4e8dd;border-top-color:#147a55;border-radius:50%;animation:loadingSpin .8s linear infinite}.tool-loading p{margin:0}@keyframes loadingSpin{to{transform:rotate(360deg)}}.tool-breadcrumb{display:flex;align-items:center;gap:9px;color:#7b8c85;margin-bottom:20px;font-size:13px;font-weight:750}.tool-breadcrumb button{display:flex;align-items:center;gap:7px;border:0;background:transparent;padding:0;cursor:pointer;color:#147a55;font-weight:850}.tool-intro{min-height:180px;border-radius:28px;background:var(--tool-accent);padding:38px 44px;position:relative;overflow:hidden;display:flex;align-items:center;border:1px solid rgba(22,41,34,.07)}.tool-intro>div{max-width:760px;position:relative;z-index:2}.tool-intro .eyebrow{color:#162922ad!important}.tool-intro h1{font-size:clamp(38px,4vw,58px);letter-spacing:-3px;margin:0 0 8px;line-height:1}.tool-intro p:not(.eyebrow){margin:0;max-width:690px;color:#162922b8;font-size:16px;line-height:1.5}.tool-intro-orb{position:absolute;width:210px;height:210px;border:25px solid rgba(255,255,255,.35);border-radius:50%;right:7%;top:-15px;box-shadow:0 0 0 38px #ffffff2e}.panel{background:#fff;border:1px solid #dce8e2;border-radius:22px;box-shadow:0 10px 32px #1629220e}.quiet-button{border:0;background:#eff6f2;color:#3a5e50;border-radius:11px;padding:9px 12px;font-size:12px;font-weight:850;display:inline-flex;align-items:center;gap:7px;cursor:pointer}.quiet-button.centered{margin:12px auto 0}.field-label{display:flex;flex-direction:column;gap:7px;color:#527066;font-weight:850;font-size:12px}select{height:46px;border:1px solid #d6e4dd;background:#fbfdfc;border-radius:12px;padding:0 13px;color:var(--ink);font-weight:750}.panel-heading{display:flex;gap:12px;align-items:center}.panel-heading h2{margin:0;font-size:23px}.step-dot{width:39px;height:39px;border-radius:13px;display:grid;place-items:center;background:#e4ffef;color:#147a55;font-weight:950}.periodic-controls{margin:22px 0;padding:14px;display:flex;align-items:center;gap:12px}.periodic-controls select{min-width:210px;height:42px}.control-tip{margin-left:auto;color:#687d74;font-size:12px;display:flex;align-items:center;gap:6px}.periodic-layout{display:grid;grid-template-columns:minmax(0,1fr) 330px;gap:20px;align-items:start}.periodic-stage{padding:20px;overflow:hidden}.table-scroll{width:100%;overflow-x:auto;padding-bottom:8px}.periodic-grid{min-width:925px;display:grid;grid-template-columns:30px repeat(18,minmax(44px,1fr));grid-template-rows:repeat(9,59px);gap:4px}.period-label,.series-label{border:0;border-radius:8px;display:grid;place-items:center;background:#eef5f1;color:#71837b;font-size:11px;font-weight:900;cursor:pointer}.period-label:hover,.period-label.active{background:#162922;color:#fff}.series-label{cursor:default;background:#e1f5e9;color:#147a55}.element-tile{min-width:0;position:relative;padding:4px 2px;border:0;border-radius:7px;background:var(--element-color);cursor:pointer;transition:transform .14s,opacity .15s,box-shadow .15s;display:flex;flex-direction:column;align-items:center;justify-content:center;overflow:hidden}.element-tile:hover{z-index:4;transform:scale(1.12);box-shadow:0 8px 18px #1629222e}.element-tile.selected{outline:3px solid #162922;outline-offset:1px;z-index:3}.element-tile.muted{opacity:.14;filter:grayscale(.7)}.element-tile strong{font-size:17px;line-height:1}.element-tile small{font-size:7px;max-width:100%;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.atomic-number{position:absolute;left:4px;top:3px;font-size:7px;font-weight:800;opacity:.66}.category-legend{display:flex;gap:7px 12px;flex-wrap:wrap;margin-top:18px;padding-top:15px;border-top:1px solid #edf2ef}.category-legend button{border:0;background:transparent;padding:3px;display:flex;align-items:center;gap:5px;font-size:9px;color:#657b72;cursor:pointer;border-radius:5px}.category-legend button.active{color:var(--ink);background:#edf5f1;font-weight:900}.category-legend i{width:10px;height:10px;border-radius:3px}.element-inspector{padding:18px;position:sticky;top:94px}.element-identity{height:126px;border-radius:17px;padding:15px;display:flex;justify-content:space-between;align-items:flex-end}.element-identity>div{display:flex;flex-direction:column}.element-identity span{font-size:12px;font-weight:900}.element-identity strong{font-size:52px;line-height:.95;font-family:Manrope,sans-serif}.element-identity p{margin:0;font-size:11px;font-weight:900;text-transform:uppercase;letter-spacing:.5px}.inspector-title{display:flex;justify-content:space-between;align-items:start;margin:19px 0 10px}.inspector-title h2{font-size:28px;margin:0}.close-inspector{border:0;background:#eff5f2;width:30px;height:30px;border-radius:9px;display:grid;place-items:center;cursor:pointer}.reactivity-note{font-size:13px;color:#61756d;line-height:1.5}.stat-grid{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin:15px 0}.stat-grid div{border:1px solid #e3ebe7;padding:10px;border-radius:11px;display:flex;flex-direction:column}.stat-grid span{font-size:9px;text-transform:uppercase;letter-spacing:.6px;color:#778a82;font-weight:900}.stat-grid strong{margin-top:2px;font-size:17px}.info-block{border-top:1px solid #e7eeea;padding-top:14px;margin-top:14px}.info-block h3{margin:0 0 10px;font-size:13px;display:flex;align-items:center;gap:7px}.info-block p,.info-block li{font-size:11px;line-height:1.45;color:#6b7d76}.info-block ul{padding-left:18px;margin:0}.isotope-row{display:flex;flex-wrap:wrap;gap:6px}.isotope-row span{padding:7px 9px;border-radius:8px;background:#eef8f2;font-weight:900}.pair-note,.model-note{font-size:11px;line-height:1.45;color:#49675c;background:#e4ffef;padding:10px;border-radius:10px;display:flex;align-items:start;gap:7px}.element-inspector .primary-button{margin-top:13px;font-size:12px}.science-canvas{height:100%;min-height:360px;border-radius:18px;overflow:hidden;position:relative;background:#071b20}.science-canvas canvas{display:block}.renderer-badge{position:absolute;right:11px;bottom:10px;z-index:5;max-width:calc(100% - 22px);padding:5px 7px;border:1px solid rgba(162,229,241,.22);border-radius:7px;background:#04181fc7;color:#c7eaf0;font-size:7px;line-height:1.2;font-weight:900;letter-spacing:.45px;text-transform:uppercase;pointer-events:none}.renderer-badge.webgpu{color:#d8ffb1;border-color:#b9f46e54}.renderer-badge.initializing{opacity:.68}.canvas-badge,.space-readout{position:absolute;left:14px;bottom:14px;padding:7px 10px;background:#ffffffe6;color:#284b40;border-radius:999px;font-size:9px;font-weight:900;text-transform:uppercase;letter-spacing:.6px;display:flex;align-items:center;gap:6px;z-index:4}.live-dot,.ready-dot{width:7px;height:7px;border-radius:50%;background:#50c886;box-shadow:0 0 0 4px #50c88626;display:inline-block;animation:livePulse 1.6s infinite}.ready-dot{background:#e6aa43;box-shadow:0 0 0 4px #e6aa4326}@keyframes livePulse{50%{opacity:.45}}.atom-layout{display:grid;grid-template-columns:minmax(0,1.55fr) minmax(320px,.65fr);gap:20px;margin-top:22px}.atom-stage{padding:10px;min-height:610px;position:relative}.atom-stage .science-canvas{height:590px;min-height:590px}.atom-overlay{position:absolute;top:26px;left:26px;display:flex;gap:8px;z-index:3}.atom-overlay>div{padding:9px 12px;min-width:86px;border-radius:11px;background:#ffffffe8;display:flex;flex-direction:column}.atom-overlay span{font-size:8px;text-transform:uppercase;letter-spacing:.7px;color:#6c8279;font-weight:900}.atom-overlay strong{font-size:13px;margin-top:2px}.atom-controls{padding:25px}.atom-controls .panel-heading{margin-bottom:22px}.isotope-control{margin-top:20px;padding:16px;background:#f4f9f6;border-radius:15px}.isotope-heading{display:flex;justify-content:space-between;align-items:center;font-size:12px;font-weight:850}.isotope-heading strong{font-size:22px}.isotope-control input[type=range],.sim-slider input,.rod-slider input{width:100%;accent-color:#147a55}.range-labels{display:flex;justify-content:space-between;font-size:8px;color:#809088}.quick-isotopes{display:flex;flex-wrap:wrap;gap:6px;margin-top:12px}.quick-isotopes button{padding:6px 8px;border-radius:8px;border:1px solid #d5e4dd;background:#fff;cursor:pointer;font-weight:850}.quick-isotopes button.active{border-color:#147a55;background:#e4ffef;color:#106b49}.particle-counts{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin:19px 0}.particle{padding:10px;border:1px solid #e1ebe6;border-radius:12px;display:flex;gap:7px;align-items:center}.particle i{width:10px;height:10px;border-radius:50%;background:#ff6f61;box-shadow:0 0 0 4px #ff6f6121}.particle.neutron i{background:#75b8e8;box-shadow:0 0 0 4px #75b8e821}.particle.electron i{background:#9bdcff;box-shadow:0 0 0 4px #9bdcff21}.particle span{display:flex;flex-direction:column;font-size:8px;color:#74887f;text-transform:uppercase;font-weight:900}.particle strong{color:var(--ink);font-size:15px}.subshell-panel{margin:0 0 14px;padding:13px;border:1px solid #d9e8e1;border-radius:14px;background:#f7fbf9}.subshell-panel>div:first-child{display:flex;flex-direction:column;gap:3px}.subshell-panel>div:first-child span{color:#52695f;font-size:8px;font-weight:900;letter-spacing:.55px;text-transform:uppercase}.subshell-panel>div:first-child strong,.subshell-notation{color:#203d34;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:10px;line-height:1.55;word-spacing:3px}.orbital-ledger{display:grid;gap:5px;margin-top:10px}.orbital-ledger.compact{gap:4px}.orbital-ledger-row{display:grid;grid-template-columns:34px 1fr;gap:7px;align-items:center;min-width:0}.orbital-ledger-row strong{color:#41564e;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:9px}.orbital-ledger-row.valence strong{color:#126b55}.orbital-boxes{display:flex;gap:2px;min-width:0}.orbital-boxes i{width:18px;height:17px;display:grid;place-items:center;border:1px solid #9fbab0;border-top:2px solid #698e80;background:#fff;color:#233d34;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:8px;font-style:normal;line-height:1}.orbital-s .orbital-boxes i{border-color:#62b9ca}.orbital-p .orbital-boxes i{border-color:#9c82ca}.orbital-d .orbital-boxes i{border-color:#c59a36}.orbital-f .orbital-boxes i{border-color:#c86783}.orbital-ledger-row.valence .orbital-boxes i{background:#e9fff4;border-top-width:3px}.orbital-inspector{max-height:290px;overflow-y:auto}.orbital-inspector .subshell-notation{margin:0 0 7px}.orbital-inspector>p:last-child{margin-bottom:0}.atom-facts{display:grid;grid-template-columns:repeat(3,1fr);gap:15px;margin:18px 0}.fact-card{background:#fff;border:1px solid #dce8e2;border-radius:19px;padding:20px}.fact-icon{width:40px;height:40px;border-radius:13px;display:grid;place-items:center;margin-bottom:15px}.fact-icon svg{width:20px}.lavender{background:#e9e2ff;color:#624ead}.coral-bg{background:#ffe1dc;color:#a94536}.mint-bg{background:#dbf8e8;color:#147a55}.fact-card p{margin:0 0 4px;color:#71837b;font-size:10px;text-transform:uppercase;letter-spacing:.7px;font-weight:900}.fact-card h3{margin:0 0 5px;font-size:20px}.fact-card span{color:#6c7d76;font-size:12px;line-height:1.45;display:block}.explain-panel{padding:27px;background:#e4ffef;border-color:#c6e6d4;display:grid;grid-template-columns:52px 1fr 35px;gap:18px;align-items:center}.explain-icon{width:52px;height:52px;display:grid;place-items:center;background:#b9f46e;color:#2e5e1a;border-radius:17px}.explain-panel h2{margin:0 0 6px;font-size:22px}.explain-panel p:not(.eyebrow){margin:0;color:#536d62;line-height:1.5;font-size:13px}.explain-spark{color:#147a55}.mode-switch{display:flex;gap:9px;width:-moz-fit-content;width:fit-content;padding:5px;border:1px solid #dce8e2;border-radius:16px;background:#fff;margin:22px 0}.mode-switch button{min-width:220px;padding:11px 16px;border-radius:11px;border:0;background:transparent;color:#647970;cursor:pointer;display:grid;grid-template-columns:25px 1fr;grid-template-rows:auto auto;text-align:left;align-items:center;font-size:13px;font-weight:900}.mode-switch button svg{grid-row:1/3}.mode-switch button span{font-size:9px;font-weight:750;opacity:.72}.mode-switch button.active{background:#162922;color:#fff}.sim-layout{display:grid;grid-template-columns:minmax(0,1.5fr) 380px;gap:20px;align-items:start}.space-stage{min-height:600px;padding:10px;position:relative;overflow:hidden}.space-stage .science-canvas{height:580px;min-height:580px}.fusion-canvas{background:#050c19}.planet-orbit{position:absolute;left:50%;top:50%;width:65%;height:28%;border-radius:50%;border:1px solid rgba(255,255,255,.18);transform:translate(-50%,-50%) rotate(-9deg);pointer-events:none}.planet-orbit.orbit-outer{width:88%;height:45%;transform:translate(-50%,-50%) rotate(14deg)}.planet{width:14px;height:14px;border-radius:50%;background:#dc8e58;position:absolute;right:8%;top:5%;box-shadow:0 0 0 4px #dc8e5826;transition:transform 1.2s,opacity 1.2s}.planet.blue{width:19px;height:19px;left:10%;top:65%;background:#68a7e1}.planet.consumed{transform:translate(-250px,80px) scale(0);opacity:0}.sim-controls{padding:25px}.sim-controls .panel-heading{margin-bottom:22px}.sim-slider{display:block;border-top:1px solid #e9efec;padding:17px 0 12px}.sim-slider>span,.rod-slider>span{display:grid;grid-template-columns:22px 1fr auto;align-items:center;gap:7px;color:#577066;font-size:11px;font-weight:850}.sim-slider svg{width:17px}.sim-slider strong,.rod-slider strong{color:var(--ink);font-size:12px}.sim-slider small{display:flex;justify-content:space-between;color:#8b9993;font-size:8px}.simulation-results{grid-column:1/-1;padding:25px;display:grid;grid-template-columns:48px 1.2fr 1fr;align-items:center;gap:18px;border-left:5px solid #58bf83}.simulation-results.warning{border-left-color:#e3a642}.result-symbol{width:48px;height:48px;display:grid;place-items:center;border-radius:15px;background:#e4ffef;color:#147a55}.warning .result-symbol{background:#fff4d6;color:#9a6a13}.simulation-results h2{margin:0 0 5px}.simulation-results p:not(.eyebrow){margin:0;color:#61746d;line-height:1.5;font-size:12px}.result-stats{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:7px}.result-stats span{padding:10px;background:#f4f8f6;border-radius:11px;display:flex;flex-direction:column;color:#74857e;font-size:8px;text-transform:uppercase;font-weight:900}.result-stats strong{color:var(--ink);font-size:11px;text-transform:none;margin-top:4px;overflow-wrap:anywhere}.stellar-archetype-picker{margin:-3px 0 8px;padding:12px;border:1px solid #dce8e2;border-radius:12px;background:#f6faf8}.stellar-archetype-picker select{width:100%;min-height:38px;border:1px solid #cfded7;border-radius:9px;padding:0 10px;background:#fff;color:var(--ink);font-weight:800}.stellar-archetype-picker small{color:#5f746b;font-size:9px;line-height:1.35}.stage-description{color:#61746d;font-size:13px;line-height:1.5;margin:0 0 18px}.choice-cards{display:grid;gap:8px;margin:15px 0 18px}.choice-cards button{border:1px solid #dbe7e1;background:#fbfdfc;border-radius:12px;padding:13px;font-weight:900;text-align:left;cursor:pointer}.choice-cards button span{display:block;color:#74867e;font-size:10px;margin-top:3px;font-weight:650}.choice-cards button.active{border-color:#147a55;background:#e4ffef}.choice-cards button.active.danger{border-color:#e07767;background:#fff1ee}.workflow-strip{grid-column:1/-1;padding:17px;display:grid;grid-template-columns:repeat(5,1fr);gap:8px}.workflow-strip>div{padding:10px;display:flex;align-items:center;gap:8px;color:#8a9892;border-radius:11px}.workflow-strip span{min-width:29px;height:29px;display:grid;place-items:center;border:1px solid #d8e3dd;border-radius:9px}.workflow-strip svg{width:15px}.workflow-strip p{margin:0;font-size:9px;font-weight:850}.workflow-strip .active{background:#e4ffef;color:#147a55}.workflow-strip .done{color:#147a55}.cutaway-toggle{position:absolute;z-index:6;top:24px;right:24px;border:1px solid rgba(255,255,255,.24);border-radius:12px;padding:9px 12px;background:#08191bd1;color:#fff;display:flex;align-items:center;gap:7px;font-size:11px;font-weight:900;cursor:pointer;box-shadow:0 9px 22px #0003}.cutaway-toggle.active{background:#b9f46ef0;color:#193715;border-color:#b9f46e}.particle-story{grid-column:1/-1;padding:22px;border-left:5px solid #b9f46e}.particle-story-heading{display:grid;grid-template-columns:42px 1fr auto;gap:12px;align-items:center}.particle-story-heading>svg,.atom-interaction-story>div:first-child>svg,.nuclear-strip-heading>svg{width:40px;height:40px;padding:9px;border-radius:12px;background:#e4ffef;color:#147a55}.particle-story h2{margin:0;font-size:21px}.particle-equation{margin:3px 0 0;color:#415f54;font-size:13px;font-weight:900}.interaction-live,.interaction-paused{padding:7px 10px;border-radius:999px;background:#e4ffef;color:#147a55;font-size:9px;font-weight:950;text-transform:uppercase;letter-spacing:.45px}.interaction-paused{background:#fff2cf;color:#8a651c}.interaction-story-steps{display:grid;grid-template-columns:repeat(3,1fr);gap:9px;margin-top:17px}.interaction-story-steps>span{border:1px solid #dfe9e4;background:#f8fbf9;border-radius:13px;padding:12px;display:grid;grid-template-columns:26px 1fr;-moz-column-gap:8px;column-gap:8px;align-items:center}.interaction-story-steps b{grid-row:1/3;width:26px;height:26px;display:grid;place-items:center;border-radius:8px;background:#b9f46e;color:#2e521d;font-size:10px}.interaction-story-steps strong{font-size:11px}.interaction-story-steps small{color:#667a72;font-size:9px;line-height:1.4}.particle-key{border-top:1px solid #e6eeea;margin-top:15px;padding-top:12px;display:flex;gap:15px;align-items:center;color:#5f756c;font-size:9px;font-weight:850}.particle-key span{display:flex;align-items:center;gap:6px}.particle-key i{width:9px;height:9px;border-radius:50%;display:inline-block}.particle-key .proton-dot{background:#ff7467}.particle-key .neutron-dot{background:#66b9ee}.particle-key .energy-dot{background:#ffe66e;box-shadow:0 0 7px #ffd84a}.particle-key small{margin-left:auto;color:#829189}.fission-layout{display:grid;grid-template-columns:minmax(0,1.45fr) 390px;gap:20px;margin-top:22px;align-items:start}.fission-stage{padding:10px;min-height:610px;position:relative}.fission-stage .science-canvas{height:590px;min-height:590px}.nuclear-label{position:absolute;left:26px;right:26px;bottom:25px;padding:14px;background:#fffffff0;border-radius:15px;display:flex;gap:12px}.nuclear-label>span{min-width:32px;height:32px;display:grid;place-items:center;background:#b9f46e;border-radius:10px;font-weight:900}.nuclear-label strong{font-size:13px}.nuclear-label p{margin:3px 0 0;color:#64776f;font-size:10px;line-height:1.4}.fission-controls{padding:25px}.fission-controls .panel-heading{margin-bottom:22px}.observation-card{min-height:170px;border-radius:15px;padding:20px;background:#f1faf5;display:flex;align-items:start;gap:12px;margin-bottom:17px}.observation-card>svg{color:#147a55}.observation-card strong{font-size:14px}.observation-card p{color:#64776f;font-size:12px;line-height:1.5}.reactor-choices{display:grid;gap:16px}.rod-slider{padding:13px;border-radius:13px;background:#f5f9f7}.rod-slider svg{width:17px}.reactor-dashboard{grid-column:1/-1;padding:23px}.reactor-status{display:grid;grid-template-columns:44px 1fr;gap:12px}.reactor-status>svg{width:38px;height:38px;padding:8px;background:#e4ffef;color:#147a55;border-radius:12px}.reactor-dashboard.hot .reactor-status>svg,.reactor-dashboard.unsafe .reactor-status>svg{background:#ffe5df;color:#ba4e3e}.reactor-status h2{margin:0 0 4px}.reactor-status p:not(.eyebrow){margin:0;color:#62766e;font-size:12px}.reactor-gauges{display:grid;grid-template-columns:repeat(4,1fr);gap:9px;margin:18px 0}.reactor-gauges>div{background:#f4f8f6;padding:12px;border-radius:12px;display:flex;gap:8px;align-items:center}.reactor-gauges svg{width:18px;color:#147a55}.reactor-gauges span{display:flex;flex-direction:column;font-size:8px;color:#788b82;text-transform:uppercase;font-weight:900}.reactor-gauges strong{font-size:11px;color:var(--ink);text-transform:capitalize}.safety-note{background:#eff8f3;color:#4e6a5f;padding:10px;border-radius:10px;display:flex;align-items:center;gap:8px;font-size:10px;margin:0}.nuclear-interaction-strip{margin-top:16px;padding:22px}.nuclear-strip-heading{display:flex;align-items:center;gap:12px}.nuclear-strip-heading h2{margin:0;font-size:21px}.nuclear-phase-list{display:grid;grid-template-columns:repeat(5,1fr);gap:8px;margin-top:17px}.nuclear-phase-list button{border:1px solid #dfe9e4;background:#f8fbf9;border-radius:13px;padding:11px;display:grid;grid-template-columns:26px 1fr;gap:8px;align-items:start;text-align:left;cursor:pointer}.nuclear-phase-list button.active{border-color:#147a55;background:#e4ffef}.nuclear-phase-list button.done{color:#147a55}.nuclear-phase-list b{width:26px;height:26px;display:grid;place-items:center;border-radius:8px;background:#e9f1ed;font-size:10px}.nuclear-phase-list .active b{background:#b9f46e}.nuclear-phase-list span{display:flex;flex-direction:column;gap:3px}.nuclear-phase-list strong{font-size:10px}.nuclear-phase-list small{color:#6c7e76;font-size:8px;line-height:1.35}.model-caveat{margin:13px 0 0;color:#6d8078;font-size:9px;line-height:1.45}.game-mode{margin-bottom:14px}.quest-brief{display:grid;grid-template-columns:auto 1fr auto;gap:17px;align-items:center;padding:18px 20px;margin-bottom:16px}.quest-number{background:#ffde69;min-width:75px;height:52px;border-radius:14px;display:grid;place-items:center;font-size:11px;font-weight:950;text-transform:uppercase}.quest-brief h2{margin:0 0 2px}.quest-brief p:not(.eyebrow){margin:0;color:#667a72;font-size:11px}.quest-actions{display:flex;align-items:center;gap:8px}.timer{padding:9px 11px;border-radius:10px;background:#f2f6f4;display:flex;align-items:center;gap:6px;font-weight:900;font-variant-numeric:tabular-nums}.timer.ready{background:#fff3bf}.quest-actions button{height:38px;border-radius:10px;border:0;padding:0 11px;background:#162922;color:#fff;display:flex;align-items:center;gap:6px;font-size:11px;font-weight:850;cursor:pointer}.free-brief{grid-template-columns:auto 1fr}.quest-success-criteria{margin-top:6px;color:#536e63;font-size:9px;line-height:1.4}.quest-success-criteria span{white-space:nowrap}.quest-number.random-assignment{display:flex;gap:6px;padding:0 10px;text-align:center}.quest-formula-unlocked{width:-moz-fit-content;width:fit-content;margin-top:8px;padding:6px 9px;border-radius:9px;background:#fff4bf;color:#5b4800;display:flex;align-items:center;gap:5px;font-size:10px;font-weight:800}.quest-formula-unlocked strong{font-size:13px}.builder-layout{display:grid;grid-template-columns:250px minmax(420px,1fr) 230px;gap:16px;align-items:start}.element-palette{padding:16px}.palette-heading,.workspace-heading,.reaction-picker-heading,.chamber-heading{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:13px}.palette-heading h2,.workspace-heading h2,.reaction-picker-heading h2,.chamber-heading h2{margin:0;font-size:20px}.element-palette .search-box{min-width:0;width:100%;height:38px}.mini-element-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:5px;max-height:478px;overflow-y:auto;padding:4px 2px 4px 0;margin-top:10px}.mini-element-grid button{position:relative;min-height:57px;border:1px solid #dce7e2;border-radius:9px;background:#f5fbf7;cursor:grab;display:flex;flex-direction:column;align-items:center;justify-content:center}.mini-element-grid button:hover{border-color:#147a55;background:#e4ffef}.mini-element-grid button>span{position:absolute;top:3px;left:5px;font-size:7px;color:#819189}.mini-element-grid strong{font-size:16px}.mini-element-grid small{font-size:6px;max-width:95%;overflow:hidden;text-overflow:ellipsis}.builder-workspace{padding:17px;min-height:590px}.builder-canvas{width:100%;height:340px;display:block;border:1px dashed #bad5c7;border-radius:16px}.composition-tray{min-height:52px;display:flex;gap:7px;align-items:center;flex-wrap:wrap;padding:10px 0}.composition-tray>p{width:100%;color:#82928b;font-size:11px;display:flex;justify-content:center;gap:8px}.composition-token{display:flex;align-items:center;gap:5px;background:#e4ffef;border:1px solid #cbe6d7;border-radius:10px;padding:5px 6px 5px 9px}.composition-token span{font-size:10px}.composition-token button{width:23px;height:23px;border:0;border-radius:7px;background:#fff;display:grid;place-items:center;cursor:pointer}.builder-model-note{margin:7px 0 0;color:#4b6057;font-size:9px;line-height:1.4}.game-message{padding:10px;display:grid;grid-template-columns:20px 1fr 23px;gap:7px;align-items:center;border-radius:10px;font-size:11px;margin-bottom:10px;background:#fff5d6;color:#705516}.game-message.success{background:#e4ffef;color:#146643}.game-message.error{background:#ffe6e1;color:#863d32}.game-message.hint{background:#fff4bf}.game-message button{border:0;background:transparent;cursor:pointer}.bond-guide{padding:18px;position:sticky;top:94px}.bond-guide h2{margin:4px 0;font-size:36px}.bond-guide>p:not(.eyebrow){margin:0 0 17px;color:#6d8078;font-size:12px}.bond-properties{display:grid;gap:6px}.bond-properties>div{border:1px solid #e1ebe6;border-radius:10px;padding:8px;display:grid;grid-template-columns:32px 1fr;align-items:center}.bond-properties span{width:29px;height:29px;display:grid;place-items:center;background:#e4ffef;border-radius:8px;font-weight:900}.bond-properties p{margin:0;font-size:9px;color:#71837b}.legend-note{margin-top:15px;padding:10px;border-radius:10px;background:#f3f7f5;color:#63766f;font-size:9px;line-height:1.4}.legend-note span{display:inline-block;background:#c6b6ff;padding:3px 5px;border-radius:5px;color:#49398c;font-weight:900;margin-right:5px}.bond-microscope{margin-top:18px;padding:24px;overflow:hidden}.bond-microscope-heading{display:flex;align-items:start;justify-content:space-between;gap:20px;margin-bottom:17px}.bond-microscope-heading h2{margin:0 0 5px;font-size:25px}.bond-microscope-heading>div:first-child>p:not(.eyebrow){margin:0;max-width:720px;color:#526a60;font-size:12px;line-height:1.5}.bond-kind{flex:0 0 auto;padding:8px 10px;border-radius:999px;background:#e3f8ff;color:#0d6584;display:flex;align-items:center;gap:5px;font-size:9px;font-weight:950;text-transform:uppercase;letter-spacing:.4px}.bond-kind.ionic{background:#ffe9df;color:#94482e}.bond-kind.polar-covalent{background:#eee8ff;color:#57419a}.bond-profile-picker{display:grid;grid-template-columns:repeat(auto-fit,minmax(88px,1fr));gap:7px;margin-bottom:14px}.bond-profile-picker button{min-width:0;min-height:54px;padding:8px 6px;border:1px solid #dbe7e1;border-radius:11px;background:#f7faf8;color:#243e34;cursor:pointer;display:flex;flex-direction:column;align-items:center;justify-content:center}.bond-profile-picker button:hover{border-color:#51957c}.bond-profile-picker button.active{border:2px solid #147a55;background:#e4ffef;box-shadow:0 4px 12px #147a551a}.bond-profile-picker strong{font-size:17px;line-height:1}.bond-profile-picker span{margin-top:4px;font-size:7px;font-weight:850;text-transform:uppercase;color:#4d635a;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:100%}.bond-lab-layout{display:grid;grid-template-columns:minmax(0,1.55fr) minmax(290px,.7fr);gap:14px;align-items:stretch}.bond-stage-wrap{min-width:0;border-radius:18px;background:#071f28;position:relative;overflow:hidden}.bond-stage-label{position:absolute;z-index:3;top:13px;left:13px;padding:7px 9px;border-radius:999px;background:#f7fefbf0;color:#284b40;display:flex;align-items:center;gap:6px;font-size:8px;font-weight:900;text-transform:uppercase;letter-spacing:.45px}.bond-stage{width:100%;height:auto;min-height:360px;display:block}.bond-stage .stage-caption{fill:#a6bac0;font-size:11px;font-weight:700;letter-spacing:.3px}.shell-atom{transition:transform .65s cubic-bezier(.22,.8,.3,1)}.atom-aura{fill:#49a2bb0b;stroke:#7dd6ee1a}.electron-shell>circle:first-child{fill:none;stroke:#4f7783;stroke-width:1.5;stroke-dasharray:3 4}.electron-shell .electron{fill:#d9f5ff;stroke:#0c485d;stroke-width:2}.electron-shell .electron.valence{fill:#ffdf6e;stroke:#6c5400;filter:drop-shadow(0 0 5px rgba(255,222,105,.8))}.shell-atom .nucleus{fill:#ff8f7e;stroke:#ffc5bb;stroke-width:3;filter:drop-shadow(0 0 9px rgba(255,126,105,.38))}.shell-atom .atom-symbol{fill:#162922;font-size:18px;font-weight:950}.shell-atom .proton-count{fill:#acc3c9;font-size:9px;font-weight:800}.whole-charge circle{fill:#fff2af;stroke:#fff;stroke-width:2}.whole-charge text{fill:#472f00;font-size:15px;font-weight:950}.density-cloud{opacity:.55;filter:blur(4px)}.force-overlay path,.transfer-electrons path,.ionic-attraction path{fill:none;stroke:#9ee9ff;stroke-width:2.5;stroke-dasharray:6 5}.force-overlay text,.transfer-electrons text,.ionic-attraction text{fill:#c9e8f0;font-size:10px;font-weight:850;letter-spacing:.25px}.transfer-electrons circle,.shared-electrons circle{fill:#ffdf6e;stroke:#fff5bb;stroke-width:2}.covalent-lines line{stroke:#c9f1ff;stroke-width:4;stroke-linecap:round;opacity:.75}.ionic-attraction text:last-child{fill:#ffe587;font-size:22px}.partial-charges text{fill:#fff0a7;font-size:19px;font-weight:950}.arrangement-label{fill:#e2f6fb;font-size:12px;font-weight:850}.bond-narration{min-height:82px;margin:-4px 13px 13px;padding:12px 14px;border:1px solid #28505b;border-radius:13px;background:#0d2b35;color:#fff;display:grid;grid-template-columns:34px 1fr;gap:10px;align-items:start}.bond-narration>span{width:31px;height:31px;display:grid;place-items:center;border-radius:9px;background:#ffde69;color:#483900;font-weight:950}.bond-narration strong{font-size:12px}.bond-narration p{margin:3px 0 0;color:#bdd0d5;font-size:10px;line-height:1.45}.bond-readout{min-width:0;padding:17px;border:1px solid #dce8e2;border-radius:18px;background:#f9fcfa;display:flex;flex-direction:column}.bond-identity{display:grid;grid-template-columns:1fr auto;align-items:center;-moz-column-gap:10px;column-gap:10px;padding-bottom:13px;border-bottom:1px solid #dce8e2}.bond-identity span{color:#526960;font-size:10px;font-weight:850}.bond-identity strong{grid-row:1/3;grid-column:2;font-size:27px}.bond-identity small{color:#38594d;font-size:9px;font-weight:800}.bond-force-card{margin:12px 0 10px;padding:12px;border-radius:12px;background:#e4f7ff;color:#153e4d}.bond-force-card>div{display:flex;gap:7px;align-items:center}.bond-force-card strong{font-size:10px}.bond-force-card p{margin:6px 0 0;color:#345763;font-size:9px;line-height:1.5}.shell-ledgers{display:grid;gap:7px}.shell-ledger{padding:10px;border:1px solid #dde8e3;border-radius:11px;background:#fff}.shell-ledger>div:first-child{display:flex;justify-content:space-between;align-items:center;gap:6px}.shell-ledger span{color:#50685e;font-size:8px;font-weight:900;text-transform:uppercase}.shell-ledger strong{font-size:13px}.shell-slots{display:grid;grid-template-columns:repeat(8,1fr);gap:3px;margin:7px 0}.shell-slots i{aspect-ratio:1;max-height:12px;border-radius:50%;border:1px solid #9cb2a9;background:#eef4f1}.shell-slots i.occupied{border-color:#846900;background:#ffde69;box-shadow:inset 0 0 0 2px #fff5c9}.shell-ledger.filled{border-color:#7cb99c;background:#edfff5}.shell-ledger p{margin:0;color:#52685f;font-size:8px;line-height:1.4}.bond-playback{display:flex;align-items:center;gap:7px;margin-top:auto;padding-top:12px}.bond-playback .primary-button{flex:1;min-height:40px;justify-content:center}.bond-playback .quiet-button{min-height:40px}.bond-phase-strip{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin-top:11px}.bond-phase-strip button{min-height:58px;padding:9px;border:1px solid #dce8e2;border-radius:12px;background:#f8fbf9;display:grid;grid-template-columns:30px 1fr;gap:8px;align-items:center;text-align:left;cursor:pointer}.bond-phase-strip button:hover{border-color:#75a994}.bond-phase-strip button.active{border-color:#147a55;background:#e4ffef}.bond-phase-strip button.complete{border-color:#b8d8c9}.bond-phase-strip i{width:29px;height:29px;border-radius:9px;background:#e9f0ed;color:#566c63;display:grid;place-items:center;font-style:normal;font-size:10px;font-weight:950}.bond-phase-strip .active i{background:#b9f46e;color:#294c18}.bond-phase-strip span{min-width:0;display:flex;flex-direction:column}.bond-phase-strip strong{font-size:10px}.bond-phase-strip small{margin-top:2px;color:#51675e;font-size:8px}.bond-science-note{margin-top:11px;padding:13px 14px;border-radius:13px;background:#fff8d7;color:#493d16;display:grid;grid-template-columns:25px 1fr auto;align-items:center;gap:10px}.bond-science-note>svg{color:#806700}.bond-science-note p{margin:0;font-size:9px;line-height:1.5}.bond-science-note span{max-width:285px;padding-left:10px;border-left:1px solid #dac765;color:#5a4b1b;display:flex;align-items:center;gap:5px;font-size:8px;font-weight:800;line-height:1.4}.quantum-method-grid{margin:18px 0 0;display:grid;grid-template-columns:repeat(3,1fr);gap:9px}.quantum-method-grid>div{min-width:0;padding:14px;border:1px solid #d5e8e9;border-radius:15px;background:#f3fcfe;display:grid;grid-template-columns:34px 1fr;gap:10px;align-items:center}.quantum-method-grid svg{width:31px;height:31px;padding:7px;border-radius:10px;background:#d8f6fc;color:#12677d}.quantum-method-grid span{display:flex;flex-direction:column;min-width:0}.quantum-method-grid strong{font-size:11px}.quantum-method-grid small{margin-top:3px;color:#4d655d;font-size:8px;line-height:1.4}.quantum-bond-stage{width:100%;height:420px;position:relative;overflow:hidden;background:#04171f}.quantum-bond-stage canvas{display:block}.quantum-atom-label{position:absolute;z-index:3;bottom:18px;min-width:76px;padding:7px 9px;border:1px solid rgba(183,235,245,.25);border-radius:10px;background:#061f28d1;color:#fff;display:flex;flex-direction:column;text-align:center;pointer-events:none}.quantum-atom-label.left{left:16%}.quantum-atom-label.right{right:16%}.quantum-atom-label strong{font-size:18px}.quantum-atom-label small{color:#b7d2d8;font-size:7px;text-transform:uppercase;letter-spacing:.45px}.quantum-charge{position:absolute;z-index:4;top:72px;width:36px;height:36px;display:grid;place-items:center;border-radius:50%;background:#fff0a8;color:#493600;font-size:17px;font-weight:950;box-shadow:0 0 24px #ffe1686b;pointer-events:none}.quantum-charge.left{left:26%}.quantum-charge.right{right:26%}.quantum-scale-note{position:absolute;z-index:3;right:13px;top:13px;max-width:190px;padding:6px 8px;border-radius:8px;background:#f7fefbe6;color:#38564c;font-size:7px;font-weight:900;text-transform:uppercase;letter-spacing:.4px;text-align:right;pointer-events:none}.substance-reveal{margin-top:18px;min-height:430px;display:grid;grid-template-columns:.9fr 1.1fr;overflow:hidden}.reveal-copy{padding:34px;display:flex;flex-direction:column;justify-content:center}.success-chip{width:-moz-fit-content;width:fit-content;padding:6px 9px;background:#e4ffef;color:#147a55;border-radius:999px;font-size:9px;font-weight:900;display:flex;gap:5px;align-items:center;margin-bottom:17px}.reveal-copy h2{font-size:34px;margin:0 0 9px}.reveal-copy h2 span{color:#147a55}.reveal-copy>p:not(.eyebrow){color:#60736b;font-size:13px;line-height:1.55}.substance-stats{display:flex;gap:8px;margin:13px 0 18px;flex-wrap:wrap}.substance-stats span{padding:10px;border-radius:10px;background:#f2f7f4;display:flex;flex-direction:column;font-size:8px;text-transform:uppercase;color:#74867e;font-weight:900}.substance-stats strong{color:var(--ink);text-transform:none;font-size:11px}.substance-reveal .science-canvas{border-radius:0;height:430px;min-height:430px}.product-view-controls{display:grid;grid-template-columns:1fr 1fr;gap:7px;margin-top:10px}.product-view-controls button{min-height:52px;padding:8px 10px;border:1px solid #d9e5df;border-radius:12px;background:#f7faf8;color:#294239;cursor:pointer;display:flex;align-items:center;gap:8px;text-align:left}.product-view-controls button:hover{border-color:#6aa78f}.product-view-controls button.active{border:2px solid #147a55;background:#e4ffef;box-shadow:0 4px 13px #147a551a}.product-view-controls span{display:flex;flex-direction:column;min-width:0}.product-view-controls strong{font-size:10px}.product-view-controls small{margin-top:2px;color:#52675e;font-size:8px}.product-model-canvas .model-label{max-width:min(390px,calc(100% - 78px))}.product-model-canvas .model-label small{max-width:340px;white-space:normal;line-height:1.3}.substance-canvas{position:relative}.substance-label{position:absolute;left:15px;bottom:15px;max-width:calc(100% - 80px);padding:8px 11px;border-radius:12px;background:#f9fffceb;display:grid;grid-template-columns:9px 1fr;-moz-column-gap:7px;column-gap:7px;align-items:center;color:#23483c}.substance-label .live-dot{grid-row:1/3}.substance-label strong{font-size:9px;text-transform:uppercase;letter-spacing:.45px}.substance-label small{font-size:7px;color:#6f817a;text-transform:uppercase;letter-spacing:.4px}.substance-formula{position:absolute;right:15px;top:15px;min-width:48px;height:48px;padding:0 10px;display:grid;place-items:center;border-radius:14px;background:#f9fffce6;color:#173b31;font-weight:950;box-shadow:0 8px 18px #0000001f}.reaction-picker{margin-top:22px;padding:21px}.reaction-elements{display:grid;grid-template-columns:repeat(auto-fit,minmax(66px,1fr));gap:7px}.reaction-elements button{min-height:76px;border:1px solid #dce8e2;background:#f7fbf9;border-radius:11px;position:relative;cursor:pointer;display:flex;flex-direction:column;align-items:center;justify-content:center;transition:opacity .2s,transform .2s}.reaction-elements button:hover{transform:translateY(-2px)}.reaction-elements button>span{position:absolute;left:6px;top:5px;font-size:8px}.reaction-elements button strong{font-size:21px}.reaction-elements button small{font-size:8px;color:#71837b}.reaction-elements button i{position:absolute;right:4px;top:4px;padding:2px 4px;background:#b9f46e;border-radius:5px;color:#385a19;font-size:6px;font-style:normal;text-transform:uppercase;font-weight:900}.reaction-elements .dimmed{opacity:.17}.reaction-elements .partner{border-color:#82bd99;background:#e4ffef}.reaction-elements .selected{border:3px solid #162922;background:#ffde69}.highlight-key{margin:13px 0 0;color:#62776e;font-size:10px;display:flex;gap:7px;align-items:center}.equation-panel{margin:15px 0;padding:18px 21px;display:grid;grid-template-columns:46px 1fr auto;align-items:center;gap:13px}.equation-icon{width:46px;height:46px;display:grid;place-items:center;border-radius:14px;background:#ffdfd9;color:#a54a3b}.equation-panel h2{margin:0 0 3px}.equation-panel p:not(.eyebrow){margin:0;color:#6c8077;font-size:10px}.conservation-badge,.safety-chip{padding:7px 9px;border-radius:999px;background:#e4ffef;color:#147a55;display:flex;gap:5px;align-items:center;font-size:9px;font-weight:900}.simulation-safety{display:block;margin-top:7px;color:#845221;font-size:9px;line-height:1.4}.reaction-workbench{display:grid;grid-template-columns:250px minmax(420px,1fr) 250px;gap:15px;align-items:stretch}.reagent-shelf,.reaction-observations{padding:18px}.reagent-shelf h2,.reaction-observations h2{margin:0 0 14px}.reagent{width:100%;border:1px solid #dce7e2;background:#f7fbf9;border-radius:13px;padding:11px;display:grid;grid-template-columns:38px 1fr 20px;gap:8px;text-align:left;align-items:center;cursor:grab;margin-bottom:8px}.reagent.added{border-color:#147a55;background:#e4ffef}.sample-vial{width:30px;height:42px;border:3px solid #8aa59a;border-top:0;border-radius:2px 2px 9px 9px;background:var(--sample-color);box-shadow:inset 0 11px #ffffff59}.reagent strong{font-size:12px}.reagent p{margin:2px 0 0;color:#71837b;font-size:8px}.reagent svg{width:15px}.drag-tip{font-size:9px;color:#74877f;display:flex;gap:5px;align-items:start;margin-top:15px}.reaction-chamber{padding:15px;min-height:470px;overflow:hidden}.beaker-scene{min-height:385px;border-radius:15px;background:#eefaf4;display:grid;place-items:center;position:relative}.beaker{width:160px;height:205px;border:8px solid rgba(105,139,126,.6);border-top:0;border-radius:4px 4px 31px 31px;position:relative;overflow:visible}.beaker:before{content:"";position:absolute;top:-7px;left:-17px;right:-17px;height:13px;border:6px solid rgba(105,139,126,.62);border-radius:50%;background:#eefaf4}.beaker-liquid{position:absolute;left:0;right:0;bottom:0;height:38%;background:#91d7ff;border-radius:0 0 21px 21px;transition:height .5s,background .5s}.beaker.mixing .beaker-liquid{height:65%;background:#ff9f8f;animation:liquidReact .45s infinite alternate}.sample-drop{position:absolute;z-index:3;top:36px;left:34px;width:42px;height:42px;border-radius:50%;background:#91d7ff;display:grid;place-items:center;font-weight:900;font-size:11px;animation:dropSample .65s both}.drop-1{left:88px;background:#ff9f8f;animation-delay:.2s}.reaction-spark{width:12px;height:12px;position:absolute;background:#fff1a1;border-radius:50%;left:40%;top:60%;box-shadow:0 0 18px 7px #ffd34e;animation:sparkBurst .7s infinite}.reaction-spark.s2{left:70%;top:40%;animation-delay:.2s}.reaction-spark.s3{left:20%;top:72%;animation-delay:.4s}@keyframes dropSample{0%{transform:translateY(-100px);opacity:0}to{transform:translateY(90px);opacity:.9}}@keyframes liquidReact{to{transform:skew(2deg)}}@keyframes sparkBurst{to{transform:translate(18px,-40px) scale(0);opacity:0}}.chamber-instructions{position:absolute;bottom:15px;color:#60766d;font-size:10px;display:flex;gap:7px;align-items:center}.reaction-chamber .science-canvas{height:385px;min-height:385px}.sensor-list{display:grid;gap:8px}.sensor-list>div{padding:10px;border-radius:11px;background:#f3f7f5;display:flex;align-items:center;gap:8px}.sensor-list svg{width:17px;color:#147a55}.sensor-list span{display:flex;flex-direction:column;font-size:8px;color:#7a8983;text-transform:uppercase;font-weight:900}.sensor-list strong{font-size:9px;color:var(--ink);text-transform:none}.product-card{margin-top:13px;padding:13px;border-radius:12px;background:#e4ffef;display:flex;flex-direction:column}.product-card span{text-transform:uppercase;font-size:8px;color:#147a55;font-weight:900}.product-card strong{font-size:14px;margin-top:3px}.product-card p{font-size:20px;font-weight:900;margin:5px 0}.product-card small{color:#557067;line-height:1.4}.reaction-summary{margin-top:15px;padding:23px;display:grid;grid-template-columns:40px 1fr auto;gap:15px;align-items:center;background:#e4ffef}.reaction-summary>svg{color:#147a55}.reaction-summary h2{margin:0 0 4px}.reaction-summary p:not(.eyebrow){margin:0;color:#577067;font-size:11px}.reaction-outcome{margin-top:15px;padding:23px;background:#f7fffa;border-color:#cfe8da}.outcome-intro{display:grid;grid-template-columns:42px 1fr;gap:12px;align-items:center}.outcome-intro>svg{width:40px;height:40px;padding:9px;border-radius:12px;background:#b9f46e;color:#315b1a}.outcome-intro h2{margin:0 0 3px}.outcome-intro p:not(.eyebrow){margin:0;color:#61756d;font-size:11px;line-height:1.45}.outcome-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:9px;margin:18px 0 13px}.outcome-grid>div{padding:13px;border:1px solid #dce9e3;border-radius:13px;background:#fff}.outcome-grid span{color:#147a55;font-size:8px;text-transform:uppercase;letter-spacing:.6px;font-weight:950}.outcome-grid strong{display:block;margin:4px 0;font-size:12px}.outcome-grid p{margin:0;color:#71827b;font-size:9px;line-height:1.4}.outcome-footer{display:flex;align-items:center;justify-content:space-between;gap:15px}.outcome-footer p{margin:0;display:flex;align-items:center;gap:7px;color:#567067;font-size:10px}.outcome-footer svg{color:#147a55}.chamber-actions{display:flex;align-items:center;gap:7px}.view-toggle{border:1px solid #cfe1d8;border-radius:10px;padding:7px 9px;background:#fff;color:#32604f;display:flex;align-items:center;gap:6px;font-size:9px;font-weight:900;cursor:pointer}.view-toggle.active{border-color:#147a55;background:#e4ffef;color:#147a55}.particle-reaction-canvas{position:relative}.particle-cycle{position:absolute;left:50%;bottom:14px;transform:translate(-50%);width:-moz-max-content;width:max-content;max-width:calc(100% - 24px);padding:7px 10px;border-radius:999px;background:#f9fffceb;color:#244c3e;display:flex;align-items:center;gap:7px;font-size:8px;font-weight:900;text-transform:uppercase;letter-spacing:.35px}.particle-cycle i{color:#147a55;font-style:normal}.particle-scale-note{position:absolute;top:13px;left:13px;z-index:4;padding:6px 8px;border-radius:8px;background:#f9fffce6;color:#536d63;font-size:7px;font-weight:900;text-transform:uppercase;letter-spacing:.45px}.atom-interaction-story{margin-top:15px;padding:21px}.atom-interaction-story>div:first-child{display:grid;grid-template-columns:42px 1fr;gap:12px;align-items:center}.atom-interaction-story>div:first-child>svg{grid-row:1/3}.atom-interaction-story h2{margin:0;font-size:21px}@media(max-width:1100px){.tool-grid{grid-template-columns:repeat(2,1fr)}.hero{grid-template-columns:1fr .75fr;padding-inline:52px}.hero h1{font-size:62px}.periodic-layout,.atom-layout,.sim-layout,.fission-layout{grid-template-columns:1fr}.element-inspector,.bond-guide{position:static}.atom-stage,.fission-stage,.space-stage{min-height:520px}.atom-stage .science-canvas,.fission-stage .science-canvas,.space-stage .science-canvas{height:500px;min-height:500px}.simulation-results,.reactor-dashboard,.workflow-strip,.particle-story{grid-column:auto}.simulation-results{grid-template-columns:48px 1fr}.result-stats{grid-column:1/-1;grid-template-columns:repeat(2,minmax(0,1fr))}.builder-layout{grid-template-columns:220px 1fr}.bond-guide{grid-column:1/-1}.bond-properties{grid-template-columns:repeat(4,1fr)}.reaction-workbench{grid-template-columns:220px 1fr}.reaction-observations{grid-column:1/-1}.sensor-list{grid-template-columns:repeat(2,1fr)}.nuclear-phase-list{grid-template-columns:repeat(3,1fr)}.readiness-grid{grid-template-columns:repeat(2,1fr)}}@media(max-width:760px){.section-shell{width:min(100% - 24px,1400px)}.site-header{height:66px}.header-nav{display:none;position:absolute;top:66px;left:12px;right:12px;background:#fff;border:1px solid #dbe7e1;border-radius:16px;padding:8px;box-shadow:0 18px 40px #16292224}.header-nav.open{display:grid}.header-nav button{justify-content:flex-start}.menu-button{display:grid}.fullscreen-button,.lab-badge{display:none}.hero{margin-top:12px;min-height:660px;grid-template-columns:1fr;padding:40px 24px 25px;align-content:start}.hero h1{font-size:49px;letter-spacing:-3px}.hero-visual{min-height:290px;transform:scale(.77);margin:-15px -50px -45px}.explorer-section{padding-top:55px}.section-heading{align-items:center}.section-heading h2{font-size:30px}.filter-bar{align-items:stretch;flex-direction:column}.search-box{min-width:0;width:100%}.grade-pills{overflow-x:auto;flex-wrap:nowrap;padding-bottom:4px}.grade-pills button{white-space:nowrap}.tool-grid{grid-template-columns:1fr}.tool-art{height:135px}.science-note{align-items:flex-start}.footer-inner{flex-direction:column;text-align:center}.tool-page{padding-top:14px}.tool-intro{min-height:210px;padding:27px 24px}.tool-intro h1{font-size:39px;letter-spacing:-2px}.tool-intro-orb{right:-80px;opacity:.7}.periodic-controls{align-items:stretch;flex-direction:column}.periodic-controls select{min-width:0}.control-tip{margin-left:0}.periodic-stage{padding:10px}.periodic-grid{min-width:840px}.atom-stage,.fission-stage,.space-stage{min-height:410px}.atom-stage .science-canvas,.fission-stage .science-canvas,.space-stage .science-canvas{height:390px;min-height:390px}.atom-overlay{flex-wrap:wrap;right:20px}.atom-overlay>div{min-width:72px}.atom-facts{grid-template-columns:1fr}.explain-panel{grid-template-columns:44px 1fr}.explain-spark{display:none}.mode-switch{width:100%}.mode-switch button{min-width:0;flex:1;padding:9px}.sim-controls,.fission-controls{padding:20px}.result-stats{grid-template-columns:1fr}.workflow-strip{overflow-x:auto;grid-template-columns:repeat(5,130px)}.reactor-gauges{grid-template-columns:1fr 1fr}.cutaway-toggle{top:18px;right:18px;padding:8px 9px;font-size:9px}.particle-story-heading{grid-template-columns:38px 1fr}.particle-story-heading>span{grid-column:1/-1;width:-moz-fit-content;width:fit-content}.interaction-story-steps{grid-template-columns:1fr}.particle-key{flex-wrap:wrap}.particle-key small{width:100%;margin-left:0}.nuclear-phase-list{display:flex;overflow-x:auto}.nuclear-phase-list button{min-width:215px}.particle-cycle{width:calc(100% - 20px);justify-content:center;flex-wrap:wrap;border-radius:12px}.chamber-heading{align-items:flex-start}.chamber-actions{align-items:flex-end;flex-direction:column-reverse}.game-mode button span{display:none}.quest-brief{grid-template-columns:auto 1fr}.quest-actions{grid-column:1/-1;justify-content:space-between}.builder-layout,.reaction-workbench{grid-template-columns:1fr}.element-palette{order:2}.builder-workspace{order:1;min-height:540px}.bond-guide{order:3}.mini-element-grid{max-height:290px;grid-template-columns:repeat(5,1fr)}.bond-properties{grid-template-columns:1fr 1fr}.builder-canvas{height:300px}.substance-reveal{grid-template-columns:1fr}.substance-reveal .science-canvas{height:350px;min-height:350px}.reaction-elements{grid-template-columns:repeat(4,1fr)}.equation-panel{grid-template-columns:42px 1fr}.conservation-badge{grid-column:1/-1;width:-moz-fit-content;width:fit-content}.reaction-chamber{min-height:430px}.reaction-outcome .outcome-grid{grid-template-columns:1fr}.outcome-footer{align-items:stretch;flex-direction:column}.outcome-footer .primary-button{width:100%}.sensor-list{grid-template-columns:1fr}}@media(max-width:920px){.bond-lab-layout{grid-template-columns:1fr}.bond-profile-picker{display:flex;overflow-x:auto;padding-bottom:4px}.bond-profile-picker button{min-width:105px}.bond-readout{min-height:0}.bond-playback{margin-top:12px}}@media(max-width:760px){.bond-microscope{padding:15px}.bond-microscope-heading{flex-direction:column;gap:10px}.bond-microscope-heading h2{font-size:21px}.bond-stage{min-height:0}.quantum-method-grid{grid-template-columns:1fr}.quantum-bond-stage{height:350px}.quantum-atom-label.left{left:9px}.quantum-atom-label.right{right:9px}.quantum-charge{top:130px}.quantum-charge.left{left:18%}.quantum-charge.right{right:18%}.quantum-scale-note{top:58px;right:10px;bottom:auto;max-width:145px}.bond-stage-label{max-width:calc(100% - 26px);border-radius:9px;white-space:normal}.bond-narration{margin-top:0}.bond-phase-strip{grid-template-columns:1fr}.bond-science-note{grid-template-columns:24px 1fr;align-items:start}.bond-science-note span{grid-column:1/-1;max-width:none;padding:9px 0 0;border-left:0;border-top:1px solid #dac765}}@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation-duration:.01ms!important;animation-iteration-count:1!important;scroll-behavior:auto!important;transition-duration:.01ms!important}}.result-count,.card-meta,.footer-inner,.tool-breadcrumb,.control-tip{color:#4b6057}.tool-intro .eyebrow,.tool-intro p:not(.eyebrow){color:#243d34!important}.mode-switch button span{color:#52655d;opacity:1}.mode-switch button.active span{color:#fff}.element-tile,.element-tile .atomic-number,.element-tile small{color:#20362e;opacity:1}.range-labels,.particle span,.fact-card p,.fact-card span,.sim-slider small{color:#4b6057}.mini-element-grid button>span,.mini-element-grid small{color:#43584f}.reaction-elements button small,.nuclear-phase-list small,.model-caveat{color:#4b6057}.composition-tray>p,.bond-guide>p:not(.eyebrow),.legend-note{color:#4b6057}.stat-grid span,.info-block p,.info-block li{color:#4b6057}@media(max-width:760px){.tool-error>div{align-items:stretch;flex-direction:column}}.tool-breadcrumb button,.category-legend button,.isotope-control input[type=range],.sim-slider input[type=range],.rod-slider input[type=range]{min-height:24px}.atom-layout>*,.fission-layout>*{min-width:0}@media(max-width:900px){.site-header{height:66px}.header-nav{display:none;position:absolute;top:66px;left:12px;right:12px;background:#fff;border:1px solid #dbe7e1;border-radius:16px;padding:8px;box-shadow:0 18px 40px #16292224}.header-nav.open{display:grid}.header-nav button{justify-content:flex-start}.menu-button{display:grid}.fullscreen-button,.lab-badge{display:none}}.lessons-callout{margin-top:4px;margin-bottom:18px;padding:25px 28px;display:grid;grid-template-columns:54px 1fr auto;gap:18px;align-items:center;background:#fffdf3;border-color:#eadfae}.lessons-callout-icon{width:54px;height:54px;border-radius:17px;display:grid;place-items:center;background:#ffde69;color:#5e4b00}.lessons-callout h2{margin:0 0 5px;font-size:23px}.lessons-callout p:not(.eyebrow){margin:0;color:#53675f;font-size:13px;line-height:1.5}.lessons-hero{min-height:320px;padding:clamp(30px,6vw,72px);overflow:hidden;display:grid;grid-template-columns:1fr 360px;align-items:center;background:#fff9d9;border-color:#ecdf9d;position:relative}.lessons-hero>div:first-child{max-width:790px;position:relative;z-index:2}.lessons-hero .eyebrow{display:flex;align-items:center;gap:7px;color:#6b5700!important}.lessons-hero h1{max-width:760px;margin:10px 0 14px;font:900 clamp(40px,5vw,68px)/1 Manrope,system-ui,sans-serif;letter-spacing:-3.5px}.lessons-hero p:not(.eyebrow){margin:0;max-width:720px;color:#59675f;line-height:1.65}.lesson-stack-art{height:210px;position:relative}.lesson-stack-art span{position:absolute;width:160px;height:95px;padding:18px;border:1px solid rgba(22,41,34,.12);border-radius:18px;background:#fff;color:#24463a;font-weight:950;text-transform:uppercase;letter-spacing:1px;box-shadow:0 16px 32px #5145071a}.lesson-stack-art span:nth-child(1){left:25px;top:5px;transform:rotate(-8deg);background:#dff6ff}.lesson-stack-art span:nth-child(2){right:5px;top:28px;transform:rotate(8deg);background:#e4ffef}.lesson-stack-art span:nth-child(3){left:5px;bottom:10px;transform:rotate(4deg);background:#ffe7e2}.lesson-stack-art span:nth-child(4){right:25px;bottom:0;transform:rotate(-5deg);background:#e8e0ff}.lesson-catalog{margin-top:62px}.lesson-grade-groups{display:grid;gap:48px}.lesson-grade-heading{display:grid;grid-template-columns:82px 1fr 44px;gap:16px;align-items:center;margin-bottom:15px}.lesson-grade-heading>span{height:66px;border-radius:19px;background:#162922;color:#fff;display:grid;place-items:center;font-weight:950}.lesson-grade-heading h3{margin:0 0 3px;font:850 24px Manrope,system-ui,sans-serif}.lesson-grade-heading p{margin:0;color:#52675e;font-size:13px}.lesson-grade-heading>strong{height:38px;border-radius:12px;background:#e4ffef;color:#126746;display:grid;place-items:center}.lesson-card-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.lesson-card{min-width:0;min-height:190px;padding:21px;border:1px solid #dce8e2;border-radius:20px;background:#fff;display:grid;grid-template-columns:37px 1fr 22px;gap:12px;align-items:start;text-align:left;cursor:pointer;box-shadow:0 8px 24px #1629220a;transition:transform .2s,border-color .2s,box-shadow .2s}.lesson-card:hover{transform:translateY(-3px);border-color:#72a991;box-shadow:0 15px 34px #16292217}.lesson-card-index{width:37px;height:37px;border-radius:12px;background:#e4ffef;color:#147a55;display:grid;place-items:center;font-size:11px;font-weight:950}.lesson-card h4{margin:1px 0 8px;font:850 18px/1.2 Manrope,system-ui,sans-serif}.lesson-card p:not(.eyebrow){margin:0;color:#52675e;font-size:12px;line-height:1.5}.lesson-card small{display:block;margin-top:15px;color:#556a61;font-size:9px;line-height:1.45;text-transform:uppercase;font-weight:850;letter-spacing:.35px}.lesson-card>svg{margin-top:7px;color:#147a55}.lesson-back{min-height:38px;margin-bottom:15px;padding:7px 11px;border:0;border-radius:10px;background:#edf6f1;color:#126746;display:inline-flex;align-items:center;gap:7px;font-size:12px;font-weight:900;cursor:pointer}.lesson-detail-header{min-height:280px;padding:clamp(28px,5vw,60px);display:grid;grid-template-columns:1fr 130px;gap:24px;align-items:center;background:#e4ffef;border-color:#cae9d7}.lesson-detail-header h1{margin:5px 0 12px;font:900 clamp(38px,5vw,62px)/1 Manrope,system-ui,sans-serif;letter-spacing:-3px}.lesson-detail-header>div>p:not(.eyebrow){margin:0;max-width:760px;color:#466257;line-height:1.55}.concept-chips{display:flex;flex-wrap:wrap;gap:6px;margin-top:20px}.concept-chips span{padding:6px 8px;border:1px solid #bcdccc;border-radius:999px;background:#ffffffb3;color:#35584a;font-size:9px;text-transform:uppercase;letter-spacing:.4px;font-weight:900}.lesson-number{justify-self:end;width:116px;height:150px;border-radius:25px;background:#162922;color:#fff;display:flex;flex-direction:column;align-items:center;justify-content:center;transform:rotate(3deg)}.lesson-number small,.lesson-number span{font-size:9px;text-transform:uppercase;letter-spacing:.7px;color:#b8ccc3;font-weight:900}.lesson-number strong{font-size:50px;line-height:1.05;font-family:Manrope,sans-serif}.lesson-learning-grid{margin-top:18px;display:grid;grid-template-columns:minmax(0,1.15fr) minmax(350px,.65fr);gap:18px;align-items:start}.lesson-reading,.lesson-interactive-column{display:grid;gap:18px}.lesson-copy,.lesson-language,.lesson-diagram,.lesson-mini,.lesson-source-note,.flashcard-panel,.practice-panel,.lesson-footer{padding:clamp(20px,3vw,32px)}.lesson-copy h2,.lesson-diagram h2,.lesson-language h2,.lesson-mini h2,.lesson-source-note h2,.recall-heading h2{margin:0 0 12px}.lesson-copy>p:not(.eyebrow){color:#405a50;line-height:1.75;font-size:15px}.lesson-copy>p:last-child{margin-bottom:0;padding:14px 16px;border-left:4px solid #147a55;border-radius:0 12px 12px 0;background:#f0faf5}.lesson-diagram{background:#fffdf4;border-color:#e6ddb5}.lesson-diagram figcaption h2{margin-bottom:20px}.diagram-flow{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;align-items:center}.diagram-flow>div{display:contents}.diagram-flow span{min-height:78px;padding:13px;border:1px solid #d6e3dd;border-radius:15px;background:#fff;display:grid;place-items:center;text-align:center;font-size:12px;font-weight:900}.diagram-flow svg{position:absolute;opacity:0}.lesson-diagram>p{margin:16px 0 0;color:#566960;font-size:11px;line-height:1.5;text-align:center}.definition-callout{display:grid;grid-template-columns:52px 1fr;gap:14px;align-items:center;padding-bottom:22px;border-bottom:1px solid #e3ebe7}.definition-callout>span{width:52px;height:52px;border-radius:16px;background:#dcd2ff;color:#513ea3;display:grid;place-items:center}.definition-callout p:not(.eyebrow){margin:0;color:#496158;line-height:1.55}.lesson-glossary{margin-top:22px}.lesson-glossary dl{display:grid;grid-template-columns:repeat(3,1fr);gap:9px;margin:0}.lesson-glossary dl>div{padding:13px;border-radius:13px;background:#f3f8f5}.lesson-glossary dt{font-weight:950;font-size:12px}.lesson-glossary dd{margin:5px 0 0;color:#4e655b;font-size:10px;line-height:1.45}.lesson-mini{position:sticky;top:94px;overflow:hidden}.mini-heading{margin-bottom:18px}.mini-heading>span{display:flex;align-items:center;gap:6px;color:#147a55;font-size:9px;font-weight:950;text-transform:uppercase;letter-spacing:.7px}.mini-heading h2{margin:6px 0 0;font-size:22px}.lesson-mini label{display:flex;flex-direction:column;gap:6px;color:#4b6258;font-size:10px;font-weight:850}.lesson-mini input[type=range]{width:100%;min-height:24px;accent-color:#147a55}.lesson-mini select{height:38px;font-size:11px}.mini-status{min-height:38px;margin:14px 0 0;padding:10px 11px;border-radius:10px;background:#f1f7f4;color:#3f5b50;font-size:10px;line-height:1.4}.mini-status.success{background:#e4ffef;color:#126746}.mini-actions{display:flex;justify-content:center;margin-top:12px}.mini-actions button,.flashcard-actions button{min-height:34px;border:1px solid #cadbd3;border-radius:10px;background:#fff;color:#2e5a49;padding:7px 10px;display:inline-flex;align-items:center;justify-content:center;gap:5px;font-size:10px;font-weight:900;cursor:pointer}.mini-segmented{display:grid;grid-template-columns:repeat(2,1fr);gap:5px;padding:4px;border-radius:12px;background:#edf4f0}.mini-segmented button{min-height:33px;border:0;border-radius:9px;background:transparent;font-size:10px;font-weight:900;cursor:pointer}.mini-segmented button.active{background:#fff;color:#147a55;box-shadow:0 3px 8px #16292214}.mini-element-row{display:grid;grid-template-columns:repeat(5,1fr);gap:5px}.mini-element-row button{min-height:62px;border:1px solid #d7e4de;border-radius:10px;background:#f7fbf9;display:flex;flex-direction:column;align-items:center;justify-content:center;cursor:pointer}.mini-element-row button.active{border:3px solid #162922;background:#ffde69}.mini-element-row small{font-size:7px}.mini-element-row strong{font-size:18px}.mini-readout{margin-top:12px;display:grid;grid-template-columns:48px 1fr;gap:10px;align-items:center}.mini-readout>span{height:48px;border-radius:13px;background:#e4ffef;color:#147a55;display:grid;place-items:center;font-size:19px;font-weight:950}.mini-readout div{display:flex;flex-direction:column}.mini-readout small{margin-top:3px;color:#53675f;font-size:9px}.mini-atom{text-align:left}.mini-nucleus{width:105px;height:105px;margin:4px auto 18px;border-radius:50%;background:#ff9f8f;border:8px solid #ffd0c8;box-shadow:0 0 0 25px #ecf5ff,0 0 0 27px #aacbe0;display:grid;place-content:center;text-align:center;position:relative;font-size:10px;font-weight:950}.mini-nucleus span{display:block}.mini-electron-orbit:before,.mini-electron-orbit:after{content:"";position:absolute;width:8px;height:8px;border-radius:50%;background:#147a55}.mini-electron-orbit:before{left:-29px;top:42px}.mini-electron-orbit:after{right:-29px;bottom:36px}.mini-sliders{display:grid;grid-template-columns:repeat(3,1fr);gap:8px}.shell-rows{display:grid;gap:7px}.shell-rows>div{display:grid;grid-template-columns:42px 1fr 30px;align-items:center;gap:7px;padding:9px;border-radius:10px;background:#f4f8f6;font-size:9px}.shell-rows>div>span{display:flex;gap:3px;flex-wrap:wrap}.shell-rows i{width:9px;height:9px;border-radius:50%;border:1px solid #9fb4aa;background:#fff}.shell-rows i.filled{border-color:#147a55;background:#147a55;box-shadow:0 0 0 2px #d4f5e2}.mini-formula>label{max-width:160px;margin:auto}.formula-atoms{min-height:110px;display:flex;align-items:center;justify-content:center;gap:8px}.formula-atoms span,.mini-molecule span,.mini-molecule strong{width:42px;height:42px;border-radius:50%;display:grid;place-items:center;border:3px solid white;box-shadow:0 0 0 1px #9eb7ac;font-size:12px}.atom-h,.mini-molecule span{background:#e6f5fb}.atom-o,.mini-molecule strong{background:#ff9f8f}.atom-c{background:#687c74;color:#fff}.atom-na{background:#c6b6ff}.atom-cl{background:#b9f46e}.atom-n{background:#91d7ff}.formula-counts{display:flex;justify-content:center;gap:7px}.formula-counts span{padding:7px 9px;border-radius:9px;background:#eef6f2;font-size:10px}.particle-box{height:140px;margin-top:12px;border:2px solid #a9bbb2;border-radius:13px;background:#f1fbf6;position:relative;overflow:hidden}.particle-box i{position:absolute;width:13px;height:13px;border-radius:50%;background:#48a880;left:calc(8% + (var(--particle-index) % 4) * 25%);top:calc(15% + (var(--particle-index) / 4) * 22%);animation:miniParticle 1.3s ease-in-out infinite alternate;animation-delay:calc(var(--particle-index) * -.07s)}.mini-matter.solid .particle-box i{animation-duration:2.4s}.mini-matter.liquid .particle-box i{animation-duration:1.25s}.mini-matter.gas .particle-box i{animation-duration:.5s;transform:translate(calc((var(--particle-index) % 3) * 12px),calc((var(--particle-index) % 2) * -15px))}.mini-matter.gas .particle-box i:nth-child(3n){top:8%}.mini-matter.gas .particle-box i:nth-child(4n){left:79%}.mini-matter.gas .particle-box i:nth-child(5n){top:72%}@keyframes miniParticle{to{translate:8px -6px}}.scale-stage{height:160px;display:grid;place-items:center}.mini-vessel{width:110px;height:130px;border:7px solid #9ab1a7;border-top:0;border-radius:0 0 22px 22px;position:relative}.mini-vessel:before{content:"";position:absolute;left:-13px;right:-13px;top:-4px;height:12px;border:5px solid #9ab1a7;border-radius:50%}.mini-vessel i{position:absolute;left:3px;right:3px;bottom:3px;height:62%;background:#91d7ff;border-radius:0 0 13px 13px}.mini-molecule{display:flex;align-items:center}.mini-molecule span:first-child{transform:translate(5px,25px)}.mini-molecule span:last-child{transform:translate(-5px,25px)}.bond-stage{min-height:150px;display:flex;align-items:center;justify-content:space-around;position:relative}.mini-bond-atom{width:64px;height:64px;border-radius:50%;background:#e9f7fb;border:4px solid white;box-shadow:0 0 0 1px #94aaa0;display:grid;place-items:center;position:relative;z-index:2;font-weight:950;transition:transform .5s}.mini-bond-atom.right{background:#b9f46e}.mini-bond-atom i{position:absolute;width:8px;height:8px;border-radius:50%;background:#147a55;right:-14px}.mini-bond-atom.right i{left:-14px;right:auto}.mini-bond.stage-1 .mini-bond-atom.left,.mini-bond.stage-2 .mini-bond-atom.left{transform:translate(32px)}.mini-bond.stage-1 .mini-bond-atom.right,.mini-bond.stage-2 .mini-bond-atom.right{transform:translate(-32px)}.bond-cloud{position:absolute;width:78px;height:38px;border-radius:50%;background:#91d7ff99;filter:blur(2px);opacity:0;transition:opacity .4s}.mini-bond.covalent.stage-1 .bond-cloud,.mini-bond.covalent.stage-2 .bond-cloud{opacity:1}.travel-electron{position:absolute;z-index:4;font-size:10px;font-weight:950;color:#147a55;opacity:0}.mini-bond.ionic.stage-1 .travel-electron{opacity:1;animation:electronTravel 1s infinite alternate}.mini-bond.ionic.stage-2 .mini-bond-atom.left:after{content:"+";position:absolute;right:0;top:-12px}.mini-bond.ionic.stage-2 .mini-bond-atom.right:after{content:"−";position:absolute;right:0;top:-12px}@keyframes electronTravel{0%{translate:-45px 0}to{translate:45px 0}}.polarity-stage{height:130px;display:flex;align-items:center;justify-content:space-between;position:relative;padding:0 18px}.polarity-stage i{width:52px;height:52px;border-radius:50%;display:grid;place-items:center;background:#e7f6fb;border:2px solid white;box-shadow:0 0 0 1px #9fb6ac;font-style:normal;font-weight:950;z-index:2}.polarity-stage i:nth-of-type(2){background:#b9f46e}.polarity-stage strong{color:#527066;font-size:11px}.polarity-cloud{position:absolute;left:calc(50% - 50px);width:100px;height:45px;border-radius:50%;background:#91d7ff8c;transition:transform .2s}.reaction-mini-stage{min-height:120px;display:flex;align-items:center;justify-content:center;gap:8px}.reaction-mini-stage .pair,.reaction-mini-stage .products{display:flex;align-items:center}.reaction-mini-stage i{width:30px;height:30px;border-radius:50%;display:grid;place-items:center;background:#e7f6fb;border:2px solid white;box-shadow:0 0 0 1px #a1b5ac;font-style:normal;font-size:9px;font-weight:950}.reaction-mini-stage .oxygen i,.reaction-mini-stage .products i:nth-child(2){background:#ff9f8f}.reaction-mini-stage .products{opacity:.2}.mini-reaction.reacted .pair,.mini-reaction.reacted>.reaction-mini-stage>b:first-of-type{opacity:.2}.mini-reaction.reacted .products{opacity:1}.reaction-mini-stage em{font-size:9px;margin-left:4px}.equation-controls{display:flex;align-items:center;justify-content:center;gap:5px;flex-wrap:wrap}.equation-controls>div{display:flex;align-items:center;gap:4px}.equation-controls button{width:28px;height:28px;border:1px solid #ccdcd4;border-radius:8px;background:#fff;cursor:pointer}.equation-controls strong{padding:7px;border-radius:8px;background:#f2f7f4;font-size:10px}.equation-controls span{margin-left:5px}.atom-ledger{display:grid;grid-template-columns:1fr 1fr;gap:7px;margin-top:15px}.atom-ledger span{padding:9px;border-radius:9px;background:#eef6f2;text-align:center;font-size:10px;font-weight:900}.energy-track{height:130px;margin-top:10px;border-bottom:3px solid #7f9389;position:relative}.energy-track:before{content:"";position:absolute;left:62%;bottom:0;width:3px;height:95px;background:#ff9f8f}.energy-track>span{position:absolute;bottom:4px;color:#147a55;transition:left .2s}.energy-barrier{position:absolute;left:calc(62% - 36px);top:8px;width:74px;text-align:center;color:#8a493f;font-size:8px;font-style:normal;font-weight:900}.mini-orbital .mini-segmented{grid-template-columns:repeat(4,1fr)}.orbital-shape{height:150px;display:grid;place-items:center;position:relative}.orbital-shape i{position:absolute;width:74px;height:74px;border-radius:50%;background:#91d7ff8f;border:1px solid rgba(21,90,137,.35)}.orbital-p i:nth-child(1),.orbital-d i:nth-child(1),.orbital-f i:nth-child(1){transform:translate(-38px) scaleX(.8)}.orbital-p i:nth-child(2),.orbital-d i:nth-child(2),.orbital-f i:nth-child(2){transform:translate(38px) scaleX(.8)}.orbital-p i:nth-child(n+3){display:none}.orbital-s i:nth-child(n+2){display:none}.orbital-d i:nth-child(3),.orbital-f i:nth-child(3){transform:translateY(-38px) scaleY(.8);background:#c6b6ff7a}.orbital-d i:nth-child(4),.orbital-f i:nth-child(4){transform:translateY(38px) scaleY(.8);background:#c6b6ff7a}.orbital-f i{border-radius:45% 55%}.fission-mini-stage{height:155px;position:relative;display:grid;place-items:center;overflow:hidden}.fission-nucleus{width:92px;height:92px;border-radius:50%;background:#c6b6ff;border:8px solid #e5deff;transition:all .45s}.fission-nucleus i{position:absolute;width:18px;height:18px;border-radius:50%;background:#8a76cf}.fission-nucleus i:nth-child(2){translate:34px 22px;background:#ff9f8f}.fission-nucleus i:nth-child(3){translate:52px 50px}.incoming-neutron{position:absolute;left:9%;width:25px;height:25px;border-radius:50%;background:#91d7ff;display:grid;place-items:center;font-size:9px;font-weight:950;transition:left .5s}.outgoing-neutrons,.fission-fragment{opacity:0;position:absolute}.fission-step-1 .incoming-neutron,.fission-step-2 .incoming-neutron{left:39%}.fission-step-2 .fission-nucleus{transform:scaleX(1.45);border-radius:40%}.fission-step-3 .fission-nucleus,.fission-step-4 .fission-nucleus,.fission-step-3 .incoming-neutron,.fission-step-4 .incoming-neutron{opacity:0}.fission-step-3 .fission-fragment,.fission-step-4 .fission-fragment{opacity:1;width:58px;height:68px;border-radius:50%;background:#c6b6ff;left:25%}.fission-step-3 .fission-fragment.two,.fission-step-4 .fission-fragment.two{left:auto;right:24%;width:50px;height:60px;background:#ff9f8f}.fission-step-3 .outgoing-neutrons,.fission-step-4 .outgoing-neutrons{opacity:1;color:#147a55;font-size:10px;font-weight:950;transform:translateY(57px)}.mini-reactor{display:grid;grid-template-columns:1fr 110px;gap:10px}.mini-reactor>label:nth-of-type(2){grid-column:1}.reactor-mini-core{grid-column:2;grid-row:1/3;height:140px;border:5px solid #8da398;border-radius:18px;position:relative;overflow:hidden;background:#e8f7ff}.reactor-mini-core span{position:absolute;left:16px;right:16px;top:0;background:#394e46;border-radius:0 0 6px 6px}.reactor-mini-core i{position:absolute;left:8px;right:8px;bottom:8px;height:48%;border-radius:10px;background:#91d7ff;box-shadow:0 0 18px #4aabdb80}.reactor-mini-core i.hot{background:#ff9f8f;box-shadow:0 0 18px #ff806d}.mini-reactor .mini-status{grid-column:1/-1}.star-mini-stage{height:170px;display:grid;place-items:center;overflow:hidden;background:#06171d;border-radius:14px;margin-top:10px}.star-mini-stage>i{width:105px;height:105px;border-radius:50%;background:var(--star-color);transform:scale(var(--star-scale));box-shadow:inset -18px -12px 26px #230a0038,inset 14px 8px 18px #ffffff80,0 0 18px 7px var(--star-color),0 0 50px 15px color-mix(in srgb,var(--star-color) 42%,transparent);position:relative}.star-mini-stage>i.pulsar:before,.star-mini-stage>i.pulsar:after{content:"";position:absolute;left:50%;width:5px;height:90px;background:#b9dcff;box-shadow:0 0 13px #75bdff;transform-origin:bottom}.star-mini-stage>i.pulsar:before{bottom:50%}.star-mini-stage>i.pulsar:after{top:50%;transform:rotate(180deg);transform-origin:top}.star-readouts{display:grid;grid-template-columns:repeat(3,1fr);gap:5px;margin-top:8px}.star-readouts span{padding:7px;border-radius:8px;background:#f0f6f3;text-align:center;font-size:9px;font-weight:900}.star-readouts small{display:block;margin-top:2px;color:#53685f;font-size:7px;text-transform:uppercase}.fusion-mini-stage{display:grid;grid-template-columns:repeat(3,1fr);gap:5px;margin-top:12px}.fusion-mini-stage span{min-height:105px;padding:10px 7px;border:1px solid #dbe6e1;border-radius:11px;background:#f4f8f6;display:flex;flex-direction:column;align-items:center;text-align:center;opacity:.38}.fusion-mini-stage span.active{opacity:1;background:#e4ffef;border-color:#8ec7a9}.fusion-mini-stage i{width:24px;height:24px;border-radius:50%;background:#162922;color:#fff;display:grid;place-items:center;font-size:8px;font-style:normal;font-weight:950}.fusion-mini-stage small{margin-top:8px;font-size:8px;line-height:1.35;color:#38564c}.tokamak-mini-stage{height:120px;display:grid;place-items:center;position:relative}.tokamak-mini-stage>span{width:170px;height:70px;border:10px solid #688b82;border-radius:50%;box-shadow:inset 0 0 18px #0a2c3459}.tokamak-mini-stage>i{position:absolute;width:125px;height:32px;border:8px solid #91d7ff;border-radius:50%;box-shadow:0 0 12px #91d7ff}.tokamak-mini-stage.ignited>i{border-color:#ffde69;box-shadow:0 0 20px #ff9f8f}.tokamak-mini-stage>b{position:absolute;color:#147a55}.mini-check{flex-direction:row!important;align-items:center;margin:7px 0}.mini-check input{width:20px;height:20px;accent-color:#147a55}.lesson-source-note{position:relative}.lesson-source-note p:not(.eyebrow){color:#4c6359;font-size:11px;line-height:1.5}.lesson-source-note a{min-height:34px;margin-top:6px;padding:8px 10px;border-radius:10px;background:#f1f7f4;color:#126746;text-decoration:none;display:flex;align-items:center;justify-content:space-between;gap:8px;font-size:10px;font-weight:850}.lesson-recall-grid{margin-top:18px;display:grid;grid-template-columns:.75fr 1.25fr;gap:18px;align-items:start}.recall-heading{display:flex;justify-content:space-between;align-items:start;gap:12px}.recall-heading h2{font-size:22px}.recall-heading>span{min-width:38px;height:30px;padding:0 7px;border-radius:9px;background:#e4ffef;color:#147a55;display:grid;place-items:center;font-size:10px;font-weight:950}.lesson-flashcard{width:100%;min-height:230px;padding:24px;border:1px solid #d6e5dd;border-radius:18px;background:#fff9d9;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;cursor:pointer;box-shadow:inset 0 -8px #6a56000d}.lesson-flashcard.flipped{background:#e4ffef}.lesson-flashcard>span{color:#6b5700;font-size:9px;font-weight:950;text-transform:uppercase;letter-spacing:.7px}.lesson-flashcard>strong{margin:13px 0;font-size:20px;line-height:1.4}.lesson-flashcard>small{color:#52675e;font-size:9px}.flashcard-actions{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-top:10px}.practice-list{display:grid;gap:16px}.practice-list fieldset{margin:0;padding:16px;border:1px solid #dce7e2;border-radius:15px}.practice-list legend{max-width:100%;padding:0 4px;display:flex;align-items:center;gap:8px;font-size:12px;font-weight:900}.practice-list legend span{min-width:24px;height:24px;border-radius:8px;background:#162922;color:#fff;display:grid;place-items:center;font-size:9px}.practice-list fieldset>div{display:grid;grid-template-columns:repeat(3,1fr);gap:6px;margin-top:8px}.practice-list fieldset button{min-height:42px;padding:8px;border:1px solid #d5e2dc;border-radius:10px;background:#fff;font-size:10px;font-weight:850;cursor:pointer;display:flex;align-items:center;justify-content:center;gap:5px}.practice-list fieldset button.correct{border-color:#147a55;background:#e4ffef;color:#126746}.practice-list fieldset button.incorrect{border-color:#b85245;background:#fff0ed;color:#8b382e}.answer-feedback{margin:9px 0 0;padding:9px 10px;border-radius:9px;background:#fff0ed;color:#773e37;font-size:10px;line-height:1.45}.answer-feedback.correct{background:#e4ffef;color:#126746}.lesson-footer{margin-top:18px;display:flex;align-items:center;justify-content:space-between;gap:20px;background:#162922;color:#fff}.lesson-footer>div{display:flex;align-items:center;gap:12px}.lesson-footer>div>svg{color:#b9f46e}.lesson-footer p{margin:0;display:flex;flex-direction:column}.lesson-footer span{margin-top:3px;color:#b9cbc3;font-size:10px}.lesson-footer .primary-button{background:#b9f46e;color:#203f18;box-shadow:none}@media(max-width:1100px){.lesson-card-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.lesson-learning-grid{grid-template-columns:1fr}.lesson-mini{position:static}.lesson-interactive-column{grid-template-columns:1fr 1fr}.lesson-recall-grid{grid-template-columns:1fr}}@media(max-width:760px){.lessons-callout{grid-template-columns:46px 1fr;padding:20px}.lessons-callout-icon{width:46px;height:46px}.lessons-callout .primary-button{grid-column:1/-1;width:100%}.lessons-hero{min-height:410px;grid-template-columns:1fr;padding:30px 24px}.lessons-hero h1{font-size:42px;letter-spacing:-2.5px}.lesson-stack-art{height:120px;transform:scale(.72);transform-origin:left top;margin-bottom:-28px}.lesson-catalog{margin-top:42px}.lesson-card-grid{grid-template-columns:1fr}.lesson-grade-heading{grid-template-columns:64px 1fr 36px}.lesson-grade-heading>span{height:56px;font-size:11px}.lesson-card{min-height:0}.lesson-detail-header{grid-template-columns:1fr;padding:28px 22px}.lesson-detail-header h1{font-size:39px;letter-spacing:-2px}.lesson-number{display:none}.lesson-learning-grid,.lesson-interactive-column,.lesson-glossary dl,.diagram-flow{grid-template-columns:1fr}.diagram-flow span{min-height:58px}.mini-sliders{grid-template-columns:1fr}.mini-nucleus{transform:scale(.82);margin-block:-5px 5px}.lesson-recall-grid{grid-template-columns:1fr}.practice-list fieldset>div{grid-template-columns:1fr}.lesson-footer{align-items:stretch;flex-direction:column}.lesson-footer .primary-button{width:100%}.fusion-mini-stage{grid-template-columns:1fr}.fusion-mini-stage span{min-height:62px;align-items:flex-start;text-align:left;flex-direction:row;gap:8px}.mini-reactor{grid-template-columns:1fr 90px}}.lesson-detail [id]{scroll-margin-top:94px}.lesson-mini{position:static}.lesson-section-nav{margin:16px 0;padding:8px;display:grid;grid-template-columns:repeat(4,1fr);gap:7px;background:#f4f8f6}.lesson-section-nav a{min-height:42px;padding:8px 12px;border-radius:11px;color:#35584a;display:grid;place-items:center;text-decoration:none;font-size:11px;font-weight:950}.lesson-section-nav a:hover,.lesson-section-nav a:focus-visible{background:#fff;color:#126746;box-shadow:0 5px 16px #16292214}.lesson-goals{padding:clamp(22px,3vw,34px);display:grid;grid-template-columns:minmax(230px,.7fr) 1.3fr;gap:28px;align-items:center;background:linear-gradient(135deg,#fff9d9,#fffdf3);border-color:#e8d989}.lesson-goals>div{display:grid;grid-template-columns:42px 1fr;-moz-column-gap:12px;column-gap:12px;align-items:center}.lesson-goals>div>svg{grid-row:1/3;width:42px;height:42px;padding:10px;border-radius:13px;background:#ffde69;color:#5e4b00}.lesson-goals .eyebrow{margin:0}.lesson-goals h2{margin:2px 0 0;font-size:21px}.lesson-goals ol{margin:0;padding:0;list-style:none;display:grid;gap:8px;counter-reset:goals}.lesson-goals li{min-height:44px;padding:10px 13px 10px 43px;border:1px solid rgba(113,93,8,.14);border-radius:12px;background:#ffffffbf;color:#3f544c;position:relative;font-size:12px;line-height:1.5}.lesson-goals li:before{counter-increment:goals;content:counter(goals);position:absolute;left:11px;top:10px;width:23px;height:23px;border-radius:8px;background:#162922;color:#fff;display:grid;place-items:center;font-size:9px;font-weight:950}.lesson-copy>section{padding:20px 0;border-top:1px solid #e2ebe6;display:grid;grid-template-columns:34px 1fr;gap:13px}.lesson-copy>section:first-of-type{border-top:0}.lesson-copy>section>span{width:30px;height:30px;border-radius:10px;background:#e4ffef;color:#126746;display:grid;place-items:center;font-size:10px;font-weight:950}.lesson-copy h3{margin:2px 0 7px;font-size:16px}.lesson-copy section p{margin:0;color:#405a50;line-height:1.75;font-size:14px}.lesson-reasoning-grid{display:grid;grid-template-columns:1.06fr .94fr;gap:18px}.worked-example,.misconception-panel,.investigation-guide,.lesson-transfer{padding:clamp(20px,3vw,28px)}.worked-example{background:#eefbff;border-color:#cde6ee}.misconception-panel{background:#fff2ef;border-color:#efcec7}.depth-heading{display:flex;align-items:flex-start;gap:12px}.depth-heading>svg{flex:0 0 auto;width:38px;height:38px;padding:9px;border-radius:12px;background:#fff;color:#147a55}.depth-heading .eyebrow{margin:0 0 3px}.depth-heading h2{margin:0;font-size:17px;line-height:1.35}.worked-example ol,.investigation-guide ol{margin:18px 0;padding:0;list-style:none;counter-reset:steps;display:grid;gap:8px}.worked-example li,.investigation-guide li{padding:11px 12px 11px 42px;border-radius:11px;background:#ffffffd1;color:#3e5b50;font-size:11px;line-height:1.5;position:relative}.worked-example li:before,.investigation-guide li:before{counter-increment:steps;content:counter(steps);position:absolute;left:11px;top:10px;width:22px;height:22px;border-radius:8px;background:#162922;color:#fff;display:grid;place-items:center;font-size:8px;font-weight:950}.worked-example>p{margin:0;padding:11px;border-radius:10px;background:#162922;color:#fff;display:flex;align-items:flex-start;gap:8px;font-size:11px;line-height:1.5}.worked-example>p svg{flex:0 0 auto;color:#b9f46e}.misconception-panel blockquote{margin:20px 0 12px;padding:14px 16px;border-left:4px solid #d76453;border-radius:0 11px 11px 0;background:#fff;color:#7b3b32;font:850 14px/1.55 Manrope,system-ui,sans-serif}.misconception-panel>p{margin:0;color:#554f4c;font-size:11px;line-height:1.6}.investigation-guide{background:#f0ecff;border-color:#d9d0f7}.investigation-guide .depth-heading>svg{color:#5844aa}.investigation-guide ol{margin-bottom:0}.lesson-transfer{display:grid;gap:14px;background:#f8fbf9}.lesson-transfer>div{display:grid;grid-template-columns:40px 1fr;align-items:center;gap:12px}.lesson-transfer>div>svg{width:40px;height:40px;padding:9px;border-radius:12px;background:#e4ffef;color:#147a55}.lesson-transfer p{margin:0;display:flex;flex-direction:column;gap:4px}.lesson-transfer p span{color:#4b6258;font-size:11px;line-height:1.55}.lesson-transfer blockquote{margin:0;padding:13px 15px;border-radius:11px;background:#fff9d9;color:#544b28;font-size:11px;line-height:1.55}.lesson-sequence-nav{margin-top:18px;display:grid;grid-template-columns:repeat(2,1fr);gap:12px}.lesson-sequence-nav button{min-height:68px;padding:12px 15px;border:1px solid #d9e6e0;border-radius:15px;background:#fff;color:#284c3e;display:flex;align-items:center;gap:10px;text-align:left;cursor:pointer}.lesson-sequence-nav button:last-child{justify-content:flex-end;text-align:right}.lesson-sequence-nav button:disabled{opacity:.42;cursor:default}.lesson-sequence-nav span{min-width:0;display:flex;flex-direction:column;gap:3px}.lesson-sequence-nav small{color:#52675e;font-size:8px;font-weight:900;text-transform:uppercase;letter-spacing:.5px}.lesson-sequence-nav strong{overflow:hidden;text-overflow:ellipsis;font-size:11px}.mini-challenge{margin:-5px 0 16px;padding:11px 12px;border:1px solid #e9d676;border-radius:12px;background:#fff9d9;color:#54470d;display:grid;grid-template-columns:22px 1fr;gap:9px;align-items:start}.mini-challenge svg{margin-top:1px}.mini-challenge strong{font-size:9px;text-transform:uppercase;letter-spacing:.45px}.mini-challenge p{margin:3px 0 0;font-size:10px;line-height:1.45}.mini-evidence{margin:16px -32px -32px;padding:12px 32px;border-top:1px solid #e0e9e4;background:#f7faf8;color:#53675f;display:flex;align-items:center;justify-content:space-between;gap:10px;font-size:9px}.mini-evidence strong{padding:5px 7px;border-radius:8px;background:#e8efeb;color:#3a554a}.mini-evidence.active{background:#edfff4;color:#126746}.mini-evidence.active strong{background:#c9f3da;color:#126746}.mini-task-row{min-height:38px;margin-bottom:10px;padding:7px 8px 7px 11px;border-radius:10px;background:#f1f7f4;display:flex;align-items:center;justify-content:space-between;gap:10px;color:#405b50;font-size:9px;line-height:1.35}.mini-task-row button{flex:0 0 auto;min-height:26px;padding:5px 8px;border:1px solid #ccddd4;border-radius:8px;background:#fff;color:#126746;font-size:8px;font-weight:900;cursor:pointer}.mini-dual-controls{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:9px}.compact-select{margin:9px 0 0}.mini-question{margin-top:12px}.mini-question input[type=number]{height:38px;border:1px solid #cbdcd3;border-radius:9px;padding:8px;font:inherit}.lesson-mini select{width:100%;border:1px solid #c9d9d1;border-radius:9px;background:#fff;padding:0 9px;color:#2f4d42}.mini-particle-model{display:flex;align-items:center;justify-content:center;flex-wrap:wrap;max-width:200px}.mini-particle-model span{width:49px;height:49px;margin:-2px;border:3px solid white;border-radius:50%;background:#e6f5fb;box-shadow:0 0 0 1px #9eb7ac;display:grid;place-items:center;color:#27483c;font-size:9px;font-weight:950}.mini-particle-model span:nth-child(2n){background:#ff9f8f}.mini-vessel.salt i,.mini-vessel.quartz i{height:50%;background:repeating-linear-gradient(135deg,#f7fbff 0 8px,#d9e5ea 8px 14px)}.mini-vessel.quartz i{background:linear-gradient(135deg,#e6f7ff,#cbbcff 54%,#fff);clip-path:polygon(50% 0,90% 25%,78% 100%,20% 100%,8% 28%)}.bond-cloud{color:#174f69;display:grid;place-items:center;filter:none;font-size:7px;font-weight:950;text-align:center}.mini-stage-picker{margin-top:6px;display:grid;grid-template-columns:repeat(3,1fr);gap:5px}.mini-stage-picker button{min-width:0;min-height:50px;padding:7px;border:1px solid #d7e3dd;border-radius:9px;background:#f5f8f6;color:#4a6158;display:flex;flex-direction:column;align-items:center;justify-content:flex-start;gap:4px;font-size:7px;line-height:1.3;font-weight:850;cursor:pointer}.mini-stage-picker button>span{width:18px;height:18px;border-radius:6px;background:#dce7e1;display:grid;place-items:center;font-size:7px}.mini-stage-picker button.active{border-color:#70aa91;background:#e4ffef;color:#126746}.mini-stage-picker button.active>span{background:#147a55;color:#fff}.mini-stage-picker.compact{grid-template-columns:repeat(5,1fr)}.dipole-arrow{position:relative;z-index:3;color:#147a55;font-weight:950}.reaction-equation{min-height:54px;margin-top:10px;padding:9px;border-radius:11px;background:#162922;color:#fff;display:grid;grid-template-columns:1fr 28px 1fr;align-items:center;text-align:center;font-size:10px}.reaction-equation svg{color:#ffde69}.reaction-particles{height:82px;margin:8px 0;border-radius:11px;background:#eff7f3;position:relative;overflow:hidden}.reaction-particles i{position:absolute;left:calc(7% + var(--reaction-particle) * 11%);top:calc(22% + (var(--reaction-particle) - 3) * 2%);width:18px;height:18px;border:2px solid white;border-radius:50%;background:#91d7ff;box-shadow:0 0 0 1px #8daaa0;transition:transform .45s,background .45s}.reaction-particles i:nth-child(2n){top:53%;background:#ff9f8f}.reaction-step-1 .reaction-particles i{transform:translate(calc((3 - var(--reaction-particle)) * 8px))}.reaction-step-2 .reaction-particles i{transform:translate(calc((3 - var(--reaction-particle)) * 11px),calc((var(--reaction-particle) - 3) * -2px));background:#ffde69}.reaction-step-3 .reaction-particles i{transform:translate(calc((var(--reaction-particle) - 3) * 5px))}.atom-ledger span.matched{background:#e4ffef;color:#126746}.energy-track:before{left:var(--barrier)}.energy-barrier{left:calc(var(--barrier) - 36px)}.energy-track.catalyzed:before{background:#7a61d0}.energy-track.endo{background:linear-gradient(to top,rgba(255,222,105,.15),transparent 55%)}.orbital-boxes{margin:9px 0;display:flex;justify-content:center;gap:4px}.orbital-boxes span{width:28px;height:36px;border:2px solid #547569;border-top:0;background:#f7fbf9;display:flex;align-items:center;justify-content:center;color:#147a55;font-size:15px;font-weight:950;letter-spacing:-4px;padding-right:4px}.generation-bars{grid-column:1/-1;height:58px;padding:7px 10px 0;border-radius:10px;background:#f1f7f4;display:flex;align-items:end;justify-content:center;gap:9px}.generation-bars>i{width:17px;min-height:5px;max-height:42px;border-radius:4px 4px 0 0;background:#147a55;position:relative}.generation-bars span{position:absolute;bottom:-12px;left:6px;color:#51665d;font-size:6px;font-style:normal}.star-mini-stage{position:relative}.star-core-layers{position:absolute;inset:50% auto auto 50%;width:82px;height:82px;transform:translate(-50%,-50%);border-radius:50%;background:#ff663b;box-shadow:inset 0 0 0 17px #ffb247,inset 0 0 0 31px #ffe285,0 0 24px #ff9650;display:grid;place-items:center}.star-core-layers span:first-child{width:20px;height:20px;border-radius:50%;background:#fff;box-shadow:0 0 13px #fff}.star-core-layers span:nth-child(n+2){display:none}.fusion-equation{margin-top:9px;padding:10px;border-radius:10px;background:#162922;color:#fff;text-align:center;font-size:9px;font-weight:850}.fusion-mini-stage button{min-height:105px;padding:10px 7px;border:1px solid #dbe6e1;border-radius:11px;background:#f4f8f6;display:flex;flex-direction:column;align-items:center;text-align:center;opacity:.42;cursor:pointer}.fusion-mini-stage button.active{opacity:1;background:#e4ffef;border-color:#8ec7a9}.mini-status svg{display:inline-block;vertical-align:middle;margin-right:4px}@media(max-width:1100px){.lesson-interactive-column{grid-template-columns:minmax(0,.85fr) minmax(0,1.15fr)}.lesson-source-note{grid-column:1/-1}}@media(max-width:760px){.lesson-section-nav{position:static;overflow-x:auto;grid-template-columns:repeat(4,minmax(90px,1fr))}.lesson-goals{grid-template-columns:1fr;gap:18px}.lesson-reasoning-grid,.lesson-interactive-column{grid-template-columns:1fr}.lesson-source-note{grid-column:auto}.lesson-copy>section{grid-template-columns:30px 1fr}.lesson-sequence-nav{grid-template-columns:1fr}.lesson-sequence-nav button:last-child{justify-content:flex-start;text-align:left}.lesson-sequence-nav button:last-child>span{order:2}.lesson-sequence-nav button:last-child>svg{order:1;transform:rotate(180deg)}.mini-evidence{margin-inline:-20px;margin-bottom:-20px;padding-inline:20px}.mini-dual-controls,.mini-stage-picker,.mini-stage-picker.compact{grid-template-columns:1fr}.mini-stage-picker button{min-height:42px;flex-direction:row;justify-content:flex-start;text-align:left}.fusion-mini-stage button{min-height:62px;align-items:flex-start;text-align:left;flex-direction:row;gap:8px}.mini-reactor{grid-template-columns:1fr 90px}}.section-shell{width:min(1440px,calc(100% - (var(--page-gutter) * 2)))}.site-header{height:78px}.header-inner{gap:var(--space-6)}.header-nav{gap:var(--space-2)}.header-nav button{padding:11px 15px}.header-actions{gap:var(--space-3)}.panel{border-radius:var(--panel-radius);box-shadow:0 12px 36px #1629220e}.hero{margin-top:var(--space-6);padding:76px clamp(48px,7vw,104px)}.explorer-section{padding-block:104px 72px}.section-heading{margin-bottom:var(--space-6)}.filter-bar{margin-bottom:var(--space-6);gap:var(--space-5)}.tool-grid{gap:var(--space-5)}.tool-card{border-radius:var(--panel-radius)}.tool-card-body{padding:26px 26px 22px}.card-meta{margin-top:var(--space-5);padding-top:var(--space-4)}.lessons-callout{margin-bottom:var(--space-5);padding:30px 32px;gap:var(--space-5)}.science-note{margin-top:var(--space-5);margin-bottom:var(--space-9);padding:30px 34px;gap:var(--space-5)}.site-footer{padding:var(--space-6) 0}.tool-page{padding-top:28px;padding-bottom:112px}.tool-breadcrumb{margin-bottom:var(--space-5)}.tool-intro{min-height:208px;padding:46px clamp(36px,4vw,58px);border-radius:32px}.tool-intro h1{margin-bottom:var(--space-3)}.tool-intro p:not(.eyebrow){line-height:1.6}.panel-heading{gap:var(--space-4)}.primary-button{min-height:46px;padding:13px 20px}.quiet-button{min-height:42px;padding:10px 14px}.periodic-controls{margin:28px 0;padding:var(--space-4);gap:var(--space-4)}.periodic-layout{gap:var(--space-5)}.periodic-stage{padding:var(--space-5)}.category-legend{margin-top:var(--space-5);padding-top:var(--space-4);gap:10px 16px}.element-inspector{padding:22px}.inspector-title{margin:var(--space-5) 0 var(--space-3)}.stat-grid{gap:var(--space-3);margin:var(--space-5) 0}.stat-grid div{padding:var(--space-3)}.info-block{padding-top:var(--space-4);margin-top:var(--space-4)}.atom-layout,.fission-layout{gap:var(--space-5);margin-top:28px}.sim-layout{gap:var(--space-5)}.atom-stage,.fission-stage,.space-stage{padding:var(--space-3)}.atom-controls,.sim-controls,.fission-controls{padding:30px}.atom-controls .panel-heading,.sim-controls .panel-heading,.fission-controls .panel-heading{margin-bottom:var(--space-6)}.isotope-control{margin-top:var(--space-5);padding:20px}.particle-counts{gap:var(--space-3);margin:var(--space-5) 0}.particle{padding:var(--space-3)}.subshell-panel{margin-bottom:var(--space-4);padding:var(--space-4)}.atom-facts{gap:var(--space-5);margin:var(--space-5) 0}.fact-card{padding:var(--space-5)}.explain-panel{padding:var(--space-6);gap:var(--space-5)}.mode-switch{margin:28px 0;gap:var(--space-3);padding:6px}.mode-switch button{padding:12px 18px}.sim-slider{padding:20px 0 14px}.simulation-results{padding:28px;gap:var(--space-5)}.result-stats{gap:var(--space-3)}.result-stats span{padding:var(--space-3)}.workflow-strip{padding:20px;gap:var(--space-3)}.workflow-strip>div{padding:var(--space-3)}.particle-story{padding:28px}.interaction-story-steps{gap:var(--space-3);margin-top:var(--space-5)}.interaction-story-steps>span{padding:var(--space-4)}.particle-key{margin-top:var(--space-5);padding-top:var(--space-4);gap:var(--space-5)}.observation-card{padding:var(--space-5);margin-bottom:var(--space-5)}.reactor-choices{gap:var(--space-5)}.rod-slider{padding:var(--space-4)}.reactor-dashboard{padding:28px}.reactor-gauges{gap:var(--space-3);margin:var(--space-5) 0}.reactor-gauges>div{padding:var(--space-4)}.safety-note{padding:var(--space-3) var(--space-4)}.nuclear-interaction-strip{margin-top:var(--space-5);padding:28px}.nuclear-phase-list{gap:var(--space-3);margin-top:var(--space-5)}.nuclear-phase-list button{padding:var(--space-4)}.model-caveat{margin-top:var(--space-4)}.game-mode{margin-bottom:var(--space-5)}.quest-brief{gap:var(--space-5);padding:var(--space-5);margin-bottom:var(--space-5)}.quest-success-criteria{margin-top:var(--space-2)}.quest-formula-unlocked{margin-top:var(--space-3);padding:7px 10px}.builder-layout{gap:20px}.element-palette{padding:20px}.palette-heading,.workspace-heading,.reaction-picker-heading,.chamber-heading{margin-bottom:var(--space-4);gap:var(--space-4)}.mini-element-grid{gap:var(--space-2);margin-top:var(--space-3)}.builder-workspace{padding:var(--space-5)}.composition-tray{padding:var(--space-4) 0;gap:var(--space-2)}.game-message{padding:var(--space-3);margin-bottom:var(--space-4)}.bond-guide{padding:22px}.bond-properties{gap:var(--space-2)}.bond-properties>div{padding:10px}.legend-note{margin-top:var(--space-4);padding:var(--space-3)}.substance-reveal{margin-top:var(--space-5)}.reveal-copy{padding:40px}.success-chip{margin-bottom:var(--space-5)}.product-view-controls{gap:var(--space-3);margin-top:var(--space-4)}.product-view-controls button{min-height:58px;padding:11px 12px}.substance-stats{gap:var(--space-3);margin:var(--space-4) 0 var(--space-5)}.substance-stats span{padding:var(--space-3)}.bond-microscope{margin-top:28px;padding:var(--space-6)}.bond-microscope-heading{gap:var(--space-5);margin-bottom:var(--space-5)}.bond-profile-picker{gap:10px;margin-bottom:var(--space-5)}.bond-profile-picker button{min-height:62px;padding:10px 8px}.bond-lab-layout{gap:20px}.bond-readout{padding:22px}.bond-identity{padding-bottom:var(--space-4)}.bond-force-card{margin:var(--space-4) 0 var(--space-3);padding:var(--space-4)}.shell-ledgers{gap:10px}.shell-ledger{padding:var(--space-3)}.bond-playback{gap:var(--space-3);padding-top:var(--space-4)}.bond-phase-strip{gap:var(--space-3);margin-top:var(--space-4)}.bond-phase-strip button{min-height:66px;padding:var(--space-3)}.bond-science-note{margin-top:var(--space-4);padding:var(--space-4) 18px;gap:var(--space-3)}.quantum-method-grid{margin-top:var(--space-5);gap:var(--space-3)}.quantum-method-grid>div{padding:var(--space-4);gap:var(--space-3)}.reaction-picker{margin-top:28px;padding:var(--space-5)}.reaction-elements{gap:10px}.reaction-elements button{min-height:82px}.highlight-key{margin-top:var(--space-4)}.equation-panel{margin:20px 0;padding:22px var(--space-5);gap:var(--space-4)}.reaction-workbench{gap:20px}.reagent-shelf,.reaction-observations{padding:22px}.reagent-shelf h2,.reaction-observations h2{margin-bottom:var(--space-4)}.reagent{padding:var(--space-3);gap:10px;margin-bottom:10px}.drag-tip{margin-top:var(--space-4)}.reaction-chamber{padding:18px}.sensor-list{gap:10px}.sensor-list>div{padding:var(--space-3)}.product-card{margin-top:var(--space-4);padding:var(--space-4)}.reaction-summary,.reaction-outcome,.atom-interaction-story{margin-top:20px;padding:28px}.outcome-grid{gap:var(--space-3);margin:var(--space-5) 0 var(--space-4)}.outcome-grid>div{padding:var(--space-4)}.outcome-footer{gap:var(--space-5)}.lessons-hero{min-height:350px;padding:clamp(42px,6vw,76px)}.lesson-catalog{margin-top:76px}.lesson-grade-groups{gap:var(--space-8)}.lesson-grade-heading{margin-bottom:var(--space-5)}.lesson-card-grid{gap:18px}.lesson-card{min-height:206px;padding:var(--space-5);gap:var(--space-4);border-radius:22px}.lesson-card h4{margin-bottom:10px}.lesson-card small{margin-top:var(--space-4)}.lesson-back{margin-bottom:var(--space-5);padding:9px 13px}.lesson-detail-header{min-height:300px;padding:clamp(36px,5vw,64px);gap:var(--space-6)}.lesson-section-nav{margin:20px 0 var(--space-5);padding:10px;gap:10px}.lesson-section-nav a{min-height:46px}.lesson-goals{padding:var(--panel-pad);gap:var(--space-6)}.lesson-learning-grid{margin-top:var(--space-5);gap:var(--space-5)}.lesson-reading,.lesson-interactive-column{gap:var(--space-5)}.lesson-copy,.lesson-language,.lesson-diagram,.lesson-mini,.lesson-source-note,.flashcard-panel,.practice-panel,.lesson-footer{padding:var(--panel-pad)}.lesson-copy>section{padding:var(--space-5) 0;gap:var(--space-4)}.lesson-reasoning-grid{gap:var(--space-5)}.worked-example,.misconception-panel,.investigation-guide,.lesson-transfer{padding:var(--panel-pad)}.worked-example ol,.investigation-guide ol{margin:var(--space-5) 0;gap:var(--space-3)}.worked-example li,.investigation-guide li{padding-block:var(--space-3)}.definition-callout{padding-bottom:var(--space-5);gap:var(--space-4)}.lesson-glossary{margin-top:var(--space-5)}.lesson-glossary dl{gap:var(--space-3)}.lesson-glossary dl>div{padding:var(--space-4)}.lesson-transfer{gap:var(--space-4)}.mini-heading{margin-bottom:var(--space-5)}.mini-challenge{margin-bottom:var(--space-5);padding:var(--space-4);gap:var(--space-3)}.mini-status{margin-top:var(--space-4);padding:var(--space-3)}.mini-actions{margin-top:var(--space-4);gap:var(--space-2)}.mini-evidence{margin-top:var(--space-5)}.lesson-source-note p:not(.eyebrow){line-height:1.6}.lesson-source-note a{min-height:40px;margin-top:var(--space-2);padding:10px 12px}.lesson-recall-grid{margin-top:var(--space-5);gap:var(--space-5)}.lesson-flashcard{min-height:250px;padding:var(--space-6)}.flashcard-actions{gap:var(--space-3);margin-top:var(--space-3)}.practice-list{gap:var(--space-5)}.practice-list fieldset{padding:20px}.practice-list fieldset>div{gap:var(--space-2);margin-top:var(--space-3)}.answer-feedback{margin-top:var(--space-3);padding:var(--space-3)}.lesson-sequence-nav{margin-top:var(--space-5);gap:var(--space-4)}.lesson-sequence-nav button{min-height:76px;padding:var(--space-4) 18px}.lesson-footer{margin-top:var(--space-5)}.nuclear-reaction-overlay{position:absolute;z-index:5;top:16px;left:16px;max-width:calc(100% - 240px);padding:10px 12px;border:1px solid rgba(185,244,110,.46);border-radius:14px;background:#f4fdf9eb;box-shadow:0 12px 32px #000f1338;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);color:#15362d;pointer-events:none}.nuclear-reaction-overlay small{display:block;margin-bottom:7px;color:#3d6557;font-size:7px;font-weight:950;text-transform:uppercase;letter-spacing:.75px}.nuclear-reaction-overlay>div{display:flex;flex-wrap:wrap;align-items:center;gap:6px;font-size:10px;font-weight:950}.nuclear-reaction-overlay span,.nuclear-reaction-overlay em,.nuclear-reaction-overlay strong{padding:6px 8px;border-radius:8px;font-style:normal;white-space:nowrap}.nuclear-reaction-overlay span{background:#e6f2ed}.nuclear-reaction-overlay em{background:#fff0af;color:#6d5100}.nuclear-reaction-overlay strong{background:#dffbec;color:#116643}.nuclear-reaction-overlay b{color:#709084;font-size:12px}.fission-reaction-overlay{top:50px;max-width:calc(100% - 32px)}.microscope-equation{margin-top:var(--space-4);padding:12px 14px;border:1px solid #d9e8e1;border-radius:13px;background:linear-gradient(135deg,#f1faf6,#fff8cf);display:flex;align-items:center;justify-content:space-between;gap:var(--space-4)}.microscope-equation span{color:#517066;font-size:8px;font-weight:950;text-transform:uppercase;letter-spacing:.55px}.microscope-equation strong{color:#183d32;font-size:12px;text-align:right}@media(max-width:1100px){:root{--page-gutter: 24px;--panel-pad: 28px}.tool-grid{gap:20px}.periodic-layout,.atom-layout,.sim-layout,.fission-layout{gap:var(--space-5)}}@media(max-width:760px){:root{--page-gutter: 16px;--panel-pad: 22px;--panel-radius: 22px}.section-shell{width:min(1440px,calc(100% - (var(--page-gutter) * 2)))}.site-header{height:68px}.header-inner{gap:var(--space-3)}.header-nav{top:68px;left:var(--space-4);right:var(--space-4);padding:var(--space-3)}.header-nav button{min-height:44px;padding:11px 13px}.hero{margin-top:var(--space-4);padding:42px var(--space-5) 30px}.explorer-section{padding-block:64px 48px}.section-heading{margin-bottom:var(--space-5)}.filter-bar{gap:var(--space-4);margin-bottom:var(--space-5)}.tool-grid{gap:var(--space-4)}.tool-card-body{padding:22px}.lessons-callout{padding:var(--space-5);gap:var(--space-4)}.science-note{margin-bottom:var(--space-8);padding:var(--space-5);gap:var(--space-4)}.site-footer{padding:var(--space-6) 0}.tool-page{padding-top:18px;padding-bottom:80px}.tool-breadcrumb{margin-bottom:var(--space-4)}.tool-intro{min-height:220px;padding:32px var(--space-5);border-radius:26px}.periodic-controls,.mode-switch,.reaction-picker,.atom-layout,.fission-layout{margin-top:var(--space-5)}.periodic-controls{margin-bottom:var(--space-5);padding:var(--space-4)}.periodic-layout,.atom-layout,.sim-layout,.fission-layout,.builder-layout,.reaction-workbench{gap:var(--space-4)}.periodic-stage{padding:var(--space-3)}.element-inspector,.atom-controls,.sim-controls,.fission-controls{padding:var(--space-5)}.atom-controls .panel-heading,.sim-controls .panel-heading,.fission-controls .panel-heading{margin-bottom:var(--space-5)}.atom-facts{gap:var(--space-4);margin:var(--space-5) 0}.fact-card{padding:var(--space-5)}.explain-panel{padding:var(--space-5);gap:var(--space-4)}.simulation-results,.reactor-dashboard,.nuclear-interaction-strip,.particle-story{padding:var(--space-5)}.workflow-strip{gap:var(--space-2);padding:var(--space-4)}.quest-brief{padding:20px;gap:var(--space-4)}.builder-workspace,.element-palette,.bond-guide{padding:20px}.reveal-copy{padding:30px var(--space-5)}.substance-reveal{margin-top:var(--space-5)}.bond-microscope{padding:20px}.bond-microscope-heading{gap:var(--space-4);margin-bottom:var(--space-5)}.bond-profile-picker{gap:var(--space-2);margin-bottom:var(--space-4)}.bond-readout{padding:20px}.bond-phase-strip{gap:10px;margin-top:var(--space-4)}.bond-phase-strip button{min-height:70px;padding:var(--space-3)}.bond-science-note{margin-top:var(--space-4);padding:var(--space-4)}.reaction-picker,.reagent-shelf,.reaction-observations,.reaction-chamber{padding:20px}.reaction-elements{gap:var(--space-2)}.equation-panel{margin:var(--space-4) 0;padding:20px}.reaction-summary,.reaction-outcome,.atom-interaction-story{margin-top:var(--space-4);padding:var(--space-5)}.lessons-hero{min-height:430px;padding:36px var(--space-5)}.lesson-catalog{margin-top:var(--space-8)}.lesson-grade-groups{gap:var(--space-7)}.lesson-grade-heading{margin-bottom:var(--space-4)}.lesson-card-grid{gap:var(--space-3)}.lesson-card{min-height:0;padding:20px;gap:var(--space-3)}.lesson-detail-header{padding:34px var(--space-5)}.lesson-section-nav{margin:var(--space-4) 0 var(--space-5);padding:var(--space-2);gap:var(--space-1);grid-template-columns:repeat(4,minmax(0,1fr));overflow-x:visible}.lesson-section-nav a{min-width:0;padding-inline:3px;font-size:10px}.lesson-learning-grid,.lesson-recall-grid,.lesson-reading,.lesson-interactive-column{gap:var(--space-4)}.lesson-copy,.lesson-language,.lesson-diagram,.lesson-mini,.lesson-source-note,.flashcard-panel,.practice-panel,.lesson-footer,.worked-example,.misconception-panel,.investigation-guide,.lesson-transfer,.lesson-goals{padding:var(--panel-pad)}.lesson-copy>section{padding:20px 0}.lesson-glossary dl{gap:10px}.lesson-flashcard{min-height:230px;padding:var(--space-5)}.practice-list fieldset{padding:var(--space-4)}.lesson-footer{gap:var(--space-5)}.mini-evidence{margin-inline:calc(var(--panel-pad) * -1);margin-bottom:calc(var(--panel-pad) * -1);padding-inline:var(--panel-pad)}.fusion-reaction-overlay{top:72px;left:10px;right:10px;max-width:none}.fission-reaction-overlay{top:48px;left:10px;right:10px;max-width:none}.nuclear-reaction-overlay{padding:9px 10px}.nuclear-reaction-overlay>div{gap:4px;font-size:8px}.nuclear-reaction-overlay span,.nuclear-reaction-overlay em,.nuclear-reaction-overlay strong{padding:5px 6px}.microscope-equation{align-items:flex-start;flex-direction:column;gap:6px}.microscope-equation strong{text-align:left}}@media(max-width:340px){.particle-counts{grid-template-columns:repeat(3,minmax(0,1fr));gap:var(--space-2)}.particle{min-width:0;padding:10px 8px;flex-direction:column;align-items:flex-start}.particle span{min-width:0}}
