/* Shared visual system. Models retain their subject-specific scientific colours. */
:root{--bg:#edf2f7;--paper:#fff;--ink:#142a3e;--muted:#52677b;--border:#d5e0e9;--accent:#096b9d;--lavender:#9ddaf7;--dark:#0b1727;--tech-cyan:#67e2eb;--tech-line:#cddce8;--tech-wash:#e9f4fa;--tech-shadow:0 12px 32px #183a5810}
body{background-color:var(--bg);background-image:radial-gradient(ellipse at 80% 0,#d9edf980,transparent 60%);color:var(--ink)}
::selection{background:#b4e8fa;color:#0b2c43}
button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid #168cc1;outline-offset:3px}
input[type=range],input[type=checkbox]{accent-color:#0876aa}
input,select,textarea{font-variant-numeric:tabular-nums}
input[type=number]{font-size:16px!important}
h1,h2,h3{text-wrap:balance}
.app-header{background:#0d1b2d;color:#edf7ff;border-bottom:1px solid #29415b;padding-left:clamp(18px,3vw,52px);padding-right:clamp(18px,3vw,52px)}
.app-header .brand{color:#edf7ff;letter-spacing:.4px}
.app-header .brand small{color:#9fb6cd;font-size:10px;letter-spacing:2px}
.app-header .brand-mark{background:#143651;color:#76e6ed;border:1px solid #2c6582;border-radius:11px;box-shadow:inset 0 0 18px #31c2ff10}
.app-header .section-tabs{background:#162a40;border:1px solid #2c4157;padding:4px;border-radius:9px}
.app-header .section-tabs a{color:#c1d2e1;border-radius:6px;font-weight:500;min-height:40px;display:flex;align-items:center;justify-content:center}
.app-header .section-tabs a:hover{background:#243c55;color:#fff}
.app-header .section-tabs a[aria-current=page]{color:#09283c;background:#a6e2f3;box-shadow:none}
.app-header .quiet-button,.app-header .header-note{color:#c1d2e1}
.app-header .learning-entry{color:#b4ecf3;border-bottom:1px solid #407586;padding-bottom:3px}
.app-header .language-picker{background:#142940;color:#e7f5ff;border:1px solid #37516c;border-radius:8px;min-height:44px}
.app-header .language-picker:hover{border-color:#74c3de;background:#1e3650}
.app-header .language-picker option{color:#15283c;background:white}
.app-header .language-name,.app-header .language-chevron{color:inherit}
.module-tabs{background:#fff;gap:6px;padding-top:9px;padding-bottom:9px;border-bottom:1px solid #d2dfea;box-shadow:0 3px 14px #18374c05}
.module-tabs a{color:#516579;border-radius:6px;min-height:42px}
.module-tabs a:hover{background:#eef6fb;color:#125778}
.module-tabs a[aria-current]{background:#e6f4fa;color:#075c88;box-shadow:inset 0 -2px #1089bc}
.eyebrow,.learn-eyebrow{font-size:11px;letter-spacing:.16em;color:#076d98;font-weight:600}
.page-heading h1,.science-heading h1,.space-heading h1,.atlas-heading h1,.sandbox-heading h1{font-size:clamp(28px,3vw,38px);letter-spacing:-.035em;line-height:1.3}
.page-heading,.science-heading,.space-heading,.atlas-heading,.sandbox-heading{margin-bottom:28px}
.page-heading p,.science-heading p,.space-heading p,.atlas-heading>p,.sandbox-heading p{color:#53687b;line-height:1.8;margin-top:12px}
.parameter-panel,.formula-panel,.insight-panel,.science-panel,.selection-panel,.recipe-panel,.space-body-panel,.observation-panel{border-color:var(--tech-line);border-radius:14px;box-shadow:var(--tech-shadow)}
.parameter-panel,.formula-panel,.science-panel{background:#fff}
.panel-title h2{letter-spacing:-.015em}
.visual-panel,.space-panel,.cell-viewer{border-color:#274660;box-shadow:0 16px 44px #0e263c18}
.sidebar{background:#f7fafc;border-color:#d5e1eb}
.experiment-button.active,.experiment-button.active:hover{background:#e0f0f9;color:#075f8f;box-shadow:inset 3px 0 #1389bd}
.experiment-button:hover{background:#ebf3f9}
.sidebar-heading,.sidebar-bottom{color:#5f7284}
.parameter-label>span:first-child{color:#125f82}
.parameter-number{background:white;border-color:#b6c9da}
.apply-button,.primary-practice,.learn-button.primary{background:#096f9f;color:#fff;border-color:#096f9f;box-shadow:0 4px 12px #08649316}
.apply-button:hover,.primary-practice:hover,.learn-button.primary:hover{background:#075b85}
.primary-practice:disabled{box-shadow:none}
.outline-button{border-color:#c2d4e2;color:#3e5b72}
.outline-button:hover{border-color:#147faf;color:#075e87;background:#f1f9fc}
.insight-panel,.formula-badge,.equation-block{background:#edf6fb;border-color:#d5e9f4;color:#174d70}
.standard-equation,.tile-equation,.selected-formula,.textbook-symbol{color:#144f77}
.symbol-table th,.symbol-table td{border-color:#dce6ee}
.symbol-table th{color:#405c74;background:#f5f9fc}
.detail-section h3,.insight-panel .panel-title{color:#125d82}
.syntax-hint,.model-note,.range-labels,.panel-subtitle,.notation-note{color:#576d80}
.symbol-chip,.symbol-token{background:#edf5fa;color:#165b82;border-color:#ccdeea}

/* Four subject doors: dark scientific shell, concise typography, no extra landing-page UI. */
.home-page{background:#091726;background-image:linear-gradient(#5099c00c 1px,transparent 1px),linear-gradient(90deg,#5099c00c 1px,transparent 1px),radial-gradient(ellipse at 50% 20%,#153750,transparent 70%);background-size:54px 54px,54px 54px,auto}
.home-header.app-header{background:transparent;border-bottom:1px solid #29415880;color:#e5f4ff;padding-top:27px;padding-bottom:27px}
.home-title{color:#e5f4ff;font-size:1.15rem;letter-spacing:.05em}
.home-main{max-width:1620px;padding-top:50px;padding-bottom:65px}
.subject-choices{gap:18px;counter-reset:subject}
.subject-choices .subject-card{counter-increment:subject;--subject-accent:#75d7f4;background:linear-gradient(155deg,#172d43,#0e2034);border:1px solid #2f4a61;border-radius:14px;box-shadow:0 24px 44px #020a131c;min-height:460px;padding:30px 26px 23px}
.subject-card::before{height:3px;width:40px;background:var(--subject-accent);margin-bottom:28px;box-shadow:0 0 17px color-mix(in srgb,var(--subject-accent) 30%,transparent)}
.subject-card::after{content:'0' counter(subject);position:absolute;top:23px;right:23px;font:12px/1.5 ui-monospace,SFMono-Regular,Consolas,monospace;color:#91acc4;letter-spacing:.15em}
.subject-choices .subject-chemistry{--subject-accent:#efbc76}
.subject-choices .subject-biology{--subject-accent:#8adac1}
.subject-choices .subject-astrophysics{--subject-accent:#b2bfff}
.subject-english{color:var(--subject-accent);font-size:11px;letter-spacing:.16em}
.subject-choices .subject-card h2{color:#f0f7ff;font-size:clamp(1.65rem,2.3vw,2.4rem);letter-spacing:-.025em;line-height:1.3}
.subject-quotation blockquote p,.subject-astrophysics .subject-blurb{color:#c9d9e8;font-size:15px;line-height:1.95}
.subject-quotation figcaption{border-top:1px solid #304860;margin-top:26px;padding-top:19px;color:#a2b7cc}
.quote-author{color:#e0edf9}.quote-edition,.quote-location{color:#a3b8cc}
.quote-book{color:var(--subject-accent)}
.subject-enter{color:var(--subject-accent)}
@media(hover:hover){.subject-choices .subject-card:hover{background:linear-gradient(155deg,#1a354e,#13273f);border-color:var(--subject-accent);box-shadow:0 22px 46px #01081150;transform:translateY(-4px)}}

/* Formula atlas: each equation has a readable, separate mathematical surface. */
.atlas-main{max-width:1440px;padding-top:36px}
.atlas-controls{border-color:#ccdae6;box-shadow:0 7px 22px #11395406;border-radius:12px;padding:20px}
.atlas-controls label{color:#46647b;font-size:13px}
.atlas-controls input,.atlas-controls select{background:#f9fcfe;color:#203e54;border-color:#bfcfdd;border-radius:6px;font-size:16px;height:46px}
.atlas-results-bar,.atlas-results-bar p{color:#4f6b81;font-variant-numeric:tabular-nums}
.formula-grid{gap:18px}
.formula-tile{--topic-color:#1480b1;border:1px solid #d0deea;border-top:3px solid var(--topic-color);border-radius:12px;padding:21px;min-height:250px;box-shadow:0 6px 18px #12304e04}
.formula-tile:hover{border-color:var(--topic-color);box-shadow:0 14px 28px #123a5514}
.topic-waves{--topic-color:#25887d}.topic-electricity{--topic-color:#b17720}.topic-thermal{--topic-color:#be6d45}.topic-modern{--topic-color:#6771af}
.tile-meta{color:#50667c;font-size:12px}
.tile-level{background:#edf5fa;color:#325c7b;border:1px solid #d5e5ee;font:11px/1.5 ui-monospace,SFMono-Regular,Consolas,monospace}
.tile-name{font-size:16px;color:#14324a;margin-top:16px}
.tile-equation{background:#f2f7fc;border:1px solid #e1eaf2;border-radius:7px;padding:13px 12px;margin:17px 0 20px;min-height:88px;font-size:23px}
.tile-foot{color:#516d82;font-size:12px}.tile-foot b{color:#116e9a}.tile-foot i{background:#7092ad}.tile-foot.has-animation i{background:#24836c}
#formula-dialog{border:1px solid #c0d4e4;border-top:4px solid #147daa;box-shadow:0 28px 90px #06162440}
#formula-dialog::backdrop{background:#051526a8;backdrop-filter:blur(5px)}
.atlas-close{background:#eaf4fa;color:#1b6087;border:1px solid #bad4e6;min-height:42px;min-width:42px}
.detail-level{color:#426d8a;font-family:ui-monospace,SFMono-Regular,Consolas,monospace}
.detail-section p{color:#496276}.detail-example{background:#f0f8f5;border-color:#d5e7df}
.detail-actions a,.guided-link{color:#085f89;border-color:#c4ddeb;background:#eaf5fb}
.detail-source{color:#446981}

/* Shared learning surfaces and the new learning-centre layout. */
.learn-surface{background:var(--bg)}
.learn-page{max-width:1440px;padding-top:34px}
.learn-card{border-color:#d2e0ea;border-radius:12px;box-shadow:0 7px 25px #15344806}
.learn-muted,.learn-subtitle{color:#536b80}
.learn-button,.learn-link{background:#edf6fb;color:#105f88;border:1px solid #c6dce9;border-radius:7px;min-height:44px}
.learn-button:hover,.learn-link:hover{background:#deeff8;border-color:#97bfd6}
.learn-button[aria-pressed=true]{background:#096c99;color:#fff;border-color:#096c99}
.learn-controls input,.learn-controls select{border-color:#b9ccdc!important;background:#fff!important;color:#203d53!important;font-size:16px!important}
.learn-tabs{display:flex;gap:8px;flex-wrap:wrap;padding:7px;border:1px solid #d0dfe9;border-radius:10px;background:#fff;margin:27px 0 24px}
.learn-tabs .learn-button{background:transparent;border-color:transparent;color:#4c687e;padding-left:19px;padding-right:19px}
.learn-tabs .learn-button[aria-pressed=true]{background:#e2f1fa;color:#0b638f;border-color:#c5deed}
.learning-hero{display:grid;grid-template-columns:minmax(0,1fr) auto;align-items:end;gap:24px;background:#10283e;border:1px solid #284c66;border-radius:15px;padding:30px 32px;color:#e9f4ff;position:relative;overflow:hidden;background-image:linear-gradient(90deg,transparent 65%,#38708b10 65%),radial-gradient(ellipse at 100% 0,#1f526a70,transparent 65%)}
.learning-hero .learn-eyebrow{color:#83dcea;font:11px/1.6 ui-monospace,SFMono-Regular,Consolas,monospace;letter-spacing:.15em}
.learning-hero h1{color:#f0f8ff;font-size:clamp(27px,3.2vw,40px);line-height:1.2;max-width:750px;letter-spacing:-.045em;margin:14px 0 12px}
.learning-hero p{color:#b7d0e2;font-size:15px;max-width:680px;line-height:1.8}
.learning-hero .learn-link{background:#b2e7f5;color:#083651;border-color:#b2e7f5;white-space:normal;text-align:center;max-width:235px;font-weight:600;padding:13px 18px}
.learning-hero .learn-link:hover{background:#d4f5ff}
.learning-quicklinks{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px;margin:22px 0 29px}
.learning-resource{display:grid;grid-template-columns:auto minmax(0,1fr);gap:18px;padding:22px;background:#fff;border:1px solid #cfdeea;border-radius:11px;text-decoration:none;box-shadow:0 4px 14px #163d5505;align-items:start}
.learning-resource:hover{border-color:#2f91b9;background:#fafdff;box-shadow:0 10px 25px #0a486e0d}
.resource-index{color:#12698f;font:12px/1.8 ui-monospace,SFMono-Regular,Consolas,monospace;padding-top:2px;border-top:2px solid #24a2c1;min-width:26px}
.learning-resource strong{display:block;font-size:17px;color:#19394f;line-height:1.4;margin-bottom:7px}
.learning-resource small{display:block;color:#536f85;font-size:13px;line-height:1.6}
.learning-workspace{display:grid;grid-template-columns:minmax(0,1fr) 260px;gap:28px;align-items:start}
.learning-content{min-width:0}
.learning-content>.learn-controls:first-child{margin-top:0}
.learning-workspace>.learning-save{position:sticky;top:20px;margin:0;padding:20px;border:1px solid #cfdee9;background:#f8fbfd;border-radius:11px;font-size:13px;color:#526d81;line-height:1.75;grid-column:2;grid-row:1}
.learning-save label{display:flex;gap:10px;align-items:flex-start;font-weight:600;color:#214c69;font-size:14px;line-height:1.6}
.learning-save input{flex:none;width:18px;height:18px;margin-top:3px}
.learning-save p{font-size:12px;margin-top:12px}
.learning-content .learn-controls{padding:18px;background:#fff;border:1px solid #d0dfea;border-radius:10px;margin-bottom:14px}
.learning-content .learn-controls label{flex:1}
.learning-content>.learn-muted{margin-bottom:20px;font-size:13px}
.route-list{gap:19px}
.route-unit{border-left:3px solid #398fb5;padding:24px 27px}
.route-unit .route-level{color:#287498;font-size:11px;letter-spacing:.07em;text-transform:uppercase}
.route-unit h3{font-size:22px;margin:10px 0;color:#173c54;letter-spacing:-.02em}
.route-unit .route-target{padding:16px 18px;background:#f3f8fc;border:1px solid #e0eaf3;border-radius:8px;font-size:14px;color:#375c75;margin-top:18px}
.route-unit .learn-actions{margin-top:20px}
.route-unit .review-tags{border-top:1px solid #e1e9f0;padding-top:16px;margin-bottom:0}
.route-unit .review-tags .learn-button{font-size:12px;padding:7px 12px;min-height:38px;background:#fff;border-color:#cfdae4;color:#526b7f}
.route-unit .review-tags .learn-button[aria-pressed=true]{background:#e1f3ed;color:#236e59;border-color:#9ecbbb}
.learn-page .route-unit+.route-unit{margin-top:0}
.search-results a{border-color:#ccdfea;border-left:3px solid #368aae;border-radius:9px}
.search-results a:hover{background:#f8fcff;border-color:#73aac8}
.bilingual-term,.search-results small{color:#536f85}
.study-recommendation{border-color:#4a9f8e;background:#eaf6f1;border-radius:8px}
.progress-chip,.term-tags span{background:#edf6fb;color:#3b627b;border-color:#ccdfeb}
.hint-panel,.review-note,.practice-options,.learning-strip{background:#edf6fb;border-color:#c8dce9;color:#325b76}
.chapter-index .learn-button{background:white;border-color:#d0deea;color:#3b5c74}
.chapter-index .learn-button[aria-pressed=true]{background:#e0f1f9;color:#0a6088;border-color:#6facce}
.term-grid a{color:#105f85;border-color:#d7e5ee}
.practice-progress [aria-current]{color:#0b6c98}.practice-progress [aria-current] b{background:#0974a3;border-color:#0974a3}
.topic-choices button,.practice-formulas button{border-color:#cddde9;box-shadow:0 5px 16px #163c5105}
.topic-choices button:hover,.practice-formulas button:hover,.practice-formulas button[aria-pressed=true]{border-color:#2481ae;background:#ecf7fc}
.topic-choices small{color:#536d80}
.guided-example{border-color:#cedee9}

@media(min-width:1350px){.learning-content .route-list{grid-template-columns:repeat(2,minmax(0,1fr))}.learning-content .route-unit{padding:22px}.learning-content .route-unit .learn-actions{display:grid;grid-template-columns:1fr}.learning-content .route-unit .learn-actions a{justify-content:flex-start}}
@media(max-width:1100px){.home-main{padding-top:35px}.subject-choices .subject-card{min-height:370px}.learning-workspace{grid-template-columns:minmax(0,1fr) 220px;gap:20px}.learning-resource{padding:18px;gap:12px}.learning-hero{padding:27px}.learning-resource strong{font-size:16px}}
@media(max-width:850px){.learning-workspace{grid-template-columns:1fr}.learning-workspace>.learning-save{position:static;grid-column:auto;grid-row:auto;margin-top:8px}.learning-hero{grid-template-columns:1fr}.learning-hero .learn-link{justify-self:start;max-width:none}.learning-quicklinks{gap:12px}.learning-resource{grid-template-columns:1fr;gap:9px}.resource-index{justify-self:start;min-width:30px}.route-unit{padding:22px}.learning-content .route-list{grid-template-columns:1fr}}
@media(max-width:600px){.app-header .brand{font-size:16px}.app-header .brand small{font-size:9px;letter-spacing:1.4px}.app-header .language-picker{padding:7px 10px}.app-header .section-tabs{width:100%;border-radius:8px}.module-tabs a{font-size:14px}.subject-choices .subject-card{min-height:0;padding:27px 24px}.home-main{padding-top:25px}.subject-choices .subject-card h2{font-size:2rem}.subject-quotation blockquote p{font-size:16px}.home-header.app-header{min-height:82px;padding:20px 22px}.formula-tile{padding:19px;min-height:235px}.tile-name{font-size:17px}.atlas-controls{padding:15px}.learning-hero{padding:24px 21px}.learning-hero h1{font-size:30px}.learning-quicklinks{grid-template-columns:1fr;margin-top:16px;gap:10px}.learning-resource{grid-template-columns:auto minmax(0,1fr);gap:16px;padding:17px 19px}.learning-resource strong{font-size:17px;margin-bottom:4px}.learning-tabs{margin-top:23px}.learn-tabs{gap:5px;padding:6px}.learn-tabs .learn-button{flex:1;min-width:110px;padding:9px 10px;font-size:13px}.learning-content .learn-controls{padding:15px}.route-unit{padding:21px}.route-unit .learn-actions{display:grid;grid-template-columns:1fr}.route-unit .learn-actions a{justify-content:flex-start}.route-unit .review-tags{gap:6px}.route-unit .review-tags .learn-button{min-height:42px}.tile-equation{font-size:24px}}
@media(prefers-reduced-motion:reduce){.subject-card,.formula-tile,.learning-resource{transition:none!important;transform:none!important}}
@media print{body,.home-page{background:#fff!important;color:#111!important}.learning-hero{background:#fff!important;border-color:#aaa;color:#111!important}.learning-hero h1,.learning-hero p,.learning-hero .learn-eyebrow{color:#111!important}.learning-quicklinks{display:none}.learning-workspace{display:block}.learn-card{box-shadow:none}}
/* Topic-first discovery, shared navigation and focused scientific images. */
.app-header .top-back{border:1px solid #496277;background:#163149;color:#edf7ff;border-radius:9px;padding:10px 14px;white-space:nowrap;font:inherit;font-size:13px;cursor:pointer}.app-header .top-back:hover{background:#244862}.top-back:focus-visible{outline:3px solid #71d7f4;outline-offset:3px}.app-header{gap:16px}.app-header .subject-tabs{flex-wrap:wrap}.app-header .subject-tabs a{white-space:nowrap;padding-inline:13px}
.atlas-controls{display:grid;grid-template-columns:minmax(220px,1fr) 210px}.atlas-topic-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}.atlas-topic-card{text-align:left;position:relative;padding:28px;border:1px solid #d5dfe9;border-top:3px solid #607eaa;border-radius:16px;background:linear-gradient(135deg,#fff,#f2f7fb);cursor:pointer;color:#162d44;min-height:235px;box-shadow:0 8px 22px #0d243a06;transition:transform .18s,box-shadow .18s}.atlas-topic-card:hover{transform:translateY(-3px);box-shadow:0 12px 30px #1d547513}.atlas-topic-card h2{font-size:23px;margin:14px 0 10px}.atlas-topic-card p{color:#687c91;line-height:1.6;min-height:50px}.topic-number{font:12px monospace;letter-spacing:.14em;color:#497b99}.topic-count{font-size:12px;color:#688095}.topic-open{display:block;margin-top:20px;color:#286b8c;font-size:13px;font-weight:600}.atlas-topic-heading{display:flex;align-items:center;gap:20px;margin-bottom:22px}.atlas-topic-heading h2{font-size:24px}.atlas-topic-card:focus-visible{outline:3px solid #398aaa;outline-offset:3px}.atlas-topic-grid[hidden],.atlas-topic-heading[hidden],.formula-grid[hidden]{display:none}
.element-tile{position:relative;padding-bottom:20px!important}.isotope-badge{position:absolute;bottom:4px;left:6px;font:600 8px/1.3 system-ui;letter-spacing:.06em;opacity:.88;border:1px solid currentColor;border-radius:3px;padding:0 2px}.isotope-legend{display:flex;align-items:center;flex-wrap:wrap;gap:7px;margin:12px 22px;color:#66778a;font-size:12px;line-height:1.7}.isotope-key{font:600 10px system-ui;border:1px solid #7695a9;padding:1px 4px;border-radius:3px}.isotope-legend a{color:#40738a}
.organ-detail-actions{display:grid;gap:16px;border-top:1px solid #e0e8eb;padding-top:22px;margin-top:24px}.organ-detail-actions>.explore-button{width:100%;min-height:46px;margin:0}.organ-detail-actions>.organ-source{margin:0;font-size:12px}
.image-zoom{width:100%;min-width:0}.image-zoom-viewport{position:relative;overflow:hidden;background:#111c28;height:270px;border-radius:10px;touch-action:none;cursor:zoom-in}.image-zoom-viewport.is-zoomed{cursor:grab}.image-zoom-viewport:active{cursor:grabbing}.microscopy-card .image-zoom-viewport img,.image-zoom-viewport img{display:block;width:100%;height:100%;object-fit:contain;max-height:none;border-radius:0;transform-origin:center;user-select:none;pointer-events:none}.image-zoom-controls{display:flex;gap:8px;align-items:center;margin:10px 0 14px}.image-zoom-controls output{min-width:48px;text-align:center;font:12px monospace}.image-zoom-controls button{min-width:38px;min-height:38px}.image-zoom-controls button:disabled{opacity:.4;cursor:default}.image-zoom-viewport:focus-visible{outline:3px solid #54afce;outline-offset:3px}.microscopy-dialog .explorer-body{display:block}.image-zoom-large{height:min(66vh,850px)}
.immune-diagram.has-selection .immune-picture{opacity:.24;filter:grayscale(.9);transition:opacity .2s}.immune-spotlight{position:absolute;inset:0;width:100%;height:100%;object-fit:contain;pointer-events:none}.immune-marker{z-index:2;transition:opacity .2s,filter .2s}.immune-marker[aria-pressed=false]{opacity:.42;filter:saturate(.25)}.immune-marker[aria-pressed=false]:hover,.immune-marker:focus-visible{opacity:1}.immune-marker[aria-pressed=true]{box-shadow:0 0 0 5px #278b7928}
@media(min-width:1440px){.home-page .subject-choices{grid-template-columns:repeat(5,minmax(0,1fr))}}@media(max-width:1250px){.app-header{flex-wrap:wrap}.app-header .subject-tabs{order:5;width:100%;justify-content:center}.app-header .learning-entry{margin-left:auto}.app-header .brand{margin-right:auto}}@media(max-width:850px){.atlas-topic-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}@media(max-width:600px){.atlas-topic-grid{grid-template-columns:1fr}.atlas-controls{grid-template-columns:1fr}.app-header{gap:9px}.app-header .top-back{font-size:12px;padding:9px}.app-header .learning-entry{display:none}.app-header .subject-tabs{justify-content:flex-start;flex-wrap:nowrap;overflow-x:auto}.app-header .subject-tabs a{padding:9px;font-size:12px}.atlas-topic-card{min-height:200px}.atlas-topic-heading{align-items:flex-start}.image-zoom-large{height:58vh}}
@media(prefers-reduced-motion:reduce){.atlas-topic-card,.immune-marker{transition:none}.atlas-topic-card:hover{transform:none}}

.subject-choices .subject-computer-science{--subject-accent:#6ee3da}.subject-computer-science .subject-blurb{color:#b3c8d9;font-size:17px;line-height:1.85;margin-top:24px}.subject-computer-science .learn-muted{color:#8da6bc}.subject-choices{grid-template-columns:repeat(3,minmax(0,1fr))}@media(min-width:1550px){.subject-choices{grid-template-columns:repeat(5,minmax(0,1fr))}.home-main{max-width:1780px}}@media(max-width:1100px){.subject-choices{grid-template-columns:repeat(2,minmax(0,1fr))}}@media(max-width:720px){.subject-choices{grid-template-columns:1fr}}

.periodic-table{grid-template-rows:23px repeat(7,90px) 13px repeat(2,90px)}.immune-mask-defs{position:absolute;pointer-events:none}.immune-spotlight{transition:opacity .2s}@media(max-width:1500px){.app-header{flex-wrap:wrap}.app-header .subject-tabs{order:5;width:100%;justify-content:center}.app-header .brand{margin-right:auto}}@media(max-width:600px){.app-header .subject-tabs{justify-content:flex-start}.atlas-controls{grid-template-columns:1fr}}

/* The same English wordmark in every language, with a compact two-line lockup. */
.app-header .brand{gap:11px;max-width:none;min-width:0;text-decoration:none;flex-shrink:0}
.app-header .brand-symbol{display:block;width:48px;height:48px;object-fit:contain;flex:none}
.app-header .brand-name{display:block;font:600 18px/1.16 'Space Grotesk',system-ui,sans-serif;letter-spacing:-.3px;color:#f0f8ff}
.app-header .brand-name>span{display:block;color:#8de2e7}
.home-header.app-header{flex-wrap:wrap}
.home-header .home-title{margin:0;margin-right:auto;letter-spacing:0;font-size:inherit}
.home-header .brand-symbol{width:52px;height:52px}
.home-header .brand-name{font-size:21px}
@media(max-width:700px){
 .app-header .brand{gap:8px}
 .app-header .brand-symbol,.home-header .brand-symbol{width:38px;height:38px}
 .app-header .brand-name,.home-header .brand-name{font-size:16px;letter-spacing:-.15px}
 .home-header .home-title{flex:1 0 auto}
}