@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;600;700&family=Playfair+Display:wght@600&display=swap');
:root{--accent:#277655;--accent-soft:#e6f2e8;--ink:#17342d;--muted:#60736c;--paper:#fbfaf5;--surface:#fff;--line:#dce4dd;--serif:'Playfair Display',Georgia,serif;--sans:'DM Sans',system-ui,sans-serif}.mathematics{--accent:#4f55b6;--accent-soft:#eeefff;--ink:#242650}.physics{--accent:#146da0;--accent-soft:#e7f3fb;--ink:#173b52}.chemistry{--accent:#a54d2d;--accent-soft:#f8e9e2;--ink:#482d23}.biology{--accent:#277655;--accent-soft:#e6f2e8;--ink:#17342d}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:100px}body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--sans);font-size:16px}.skip-link{position:fixed;top:-80px;left:12px;z-index:30;background:#fff;padding:12px}.skip-link:focus{top:8px}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0)}button,input,textarea,select{font:inherit;color:inherit}.app-header{height:84px;padding:0 28px;display:flex;align-items:center;gap:28px;background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:20}.brand img{display:block;width:150px}.subject-switcher{display:flex;gap:7px;margin:auto}.subject-switcher a{padding:9px 12px;border-radius:999px;text-decoration:none;color:#53645f;font-size:.82rem}.subject-switcher a[aria-current]{background:var(--accent-soft);color:var(--accent);font-weight:700}.searchwrap{position:relative}.searchwrap input{width:230px;border:1px solid var(--line);border-radius:999px;background:#f8faf8;padding:11px 16px}.searchwrap #results{position:absolute;right:0;top:50px;width:min(390px,90vw);max-height:420px;overflow:auto;background:#fff;border:1px solid var(--line);border-radius:14px;box-shadow:0 18px 60px #17342d22;padding:8px}.searchwrap #results button{display:block;width:100%;text-align:left;border:0;background:transparent;padding:12px;border-radius:9px}.searchwrap #results button:hover{background:var(--accent-soft)}.searchwrap #results small{display:block;color:var(--muted);margin-top:4px}body.subject-page > #workspace{display:grid;grid-template-columns:300px minmax(0,1fr);min-height:calc(100vh - 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@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}
.bio-flow{display:flex;gap:12px;align-items:center;flex-wrap:wrap}.bio-flow b,.term-list span{background:#fff;border:1px solid var(--line);border-radius:999px;padding:10px 14px}.term-list{display:flex;gap:9px;flex-wrap:wrap}.photo-atlas{display:grid;grid-template-columns:.8fr 1.2fr;gap:24px;background:#183d31;color:white;border-radius:20px;padding:30px;margin:35px 0}.photo-atlas h3{margin:12px 0!important}.leaf-diagram{display:grid;grid-template-columns:repeat(2,1fr);gap:9px;background:radial-gradient(ellipse at center,#5f9b62,#2b6244 70%);padding:35px;border-radius:50% 15% 50% 15%;min-height:330px}.leaf-diagram button{border:1px solid #ffffff55;background:#ffffffed;color:#17342d;border-radius:12px;padding:13px;font-weight:700;cursor:pointer}.leaf-diagram button[aria-pressed=true]{background:#d9ed72;outline:3px solid #d9ed7255}.leaf-diagram span{display:block;font-size:.72rem;margin-top:4px}.event-grid{display:grid;grid-template-columns:.8fr 1.2fr;gap:15px}.event-tabs{display:grid;gap:8px}.event-tabs button{border:1px solid var(--line);background:#fff;border-radius:12px;padding:17px;text-align:left;cursor:pointer}.event-tabs button[aria-pressed=true]{background:var(--accent-soft);border-color:var(--accent);color:var(--accent)}.event-story{background:var(--accent-soft);border-radius:16px;padding:25px}.event-story h3{margin:10px 0!important}.photo-lab{display:grid;grid-template-columns:1fr 1fr;background:#183d31;color:white;border-radius:18px;overflow:hidden}.lab-controls,.lab-result{padding:28px}.lab-controls label{display:block;margin-bottom:22px}.lab-controls output{float:right}.lab-controls input[type=range]{display:block;width:100%;margin-top:10px;accent-color:#d9ed72}.water-check{display:flex!important;gap:9px}.lab-controls button,.observations button,.photo-quiz button{border:1px solid #ffffff55;border-radius:999px;padding:10px 14px;background:transparent;color:inherit;margin:4px;cursor:pointer}.lab-result{background:#234e3e}.lab-result>strong{display:block;font:5rem var(--serif)}.lab-result meter{width:100%;height:20px}.observations{border:1px solid var(--line);padding:20px;border-radius:14px;margin-top:14px}.observations button,.photo-quiz button{color:var(--accent);border-color:var(--accent)}.photo-quiz label{display:block;padding:10px;border:1px solid var(--line);border-radius:9px;margin:7px 0}.photo-quiz input{accent-color:var(--accent)}
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#lesson [data-lesson-start]{scroll-margin-top:100px}.section-nav{display:flex;gap:8px;flex-wrap:wrap;margin:0 0 30px}.subject-page #lesson .section-nav :is(a,button){border:1px solid var(--line);min-height:44px;cursor:pointer;color:var(--accent);background:var(--accent-soft);border-radius:999px;padding:9px 13px;text-decoration:none;font-weight:700;font-size:.82rem}.comparison{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.comparison article{background:#fff;border:1px solid var(--line);border-radius:14px;padding:18px}.comparison h4{color:var(--accent)}.journey{list-style:none;padding:0;counter-reset:journey}.journey li{counter-increment:journey;margin:10px 0}.journey button{width:100%;display:grid;grid-template-columns:55px 180px 1fr;gap:18px;text-align:left;border:1px solid var(--line);background:#fff;border-radius:12px;padding:17px;cursor:pointer}.journey button:before{content:counter(journey,decimal-leading-zero);color:var(--accent);font-weight:700}.label-practice button,.match-practice button{border:1px solid var(--accent);background:#fff;border-radius:999px;padding:10px 14px;margin:4px;cursor:pointer}.match-practice [aria-pressed=true]{background:var(--accent);color:#fff}@media(max-width:650px){.comparison{grid-template-columns:1fr}.journey button{grid-template-columns:45px 1fr}.journey button span{grid-column:2}}

body.biology [hidden]{display:none!important}


/* Focus and contrast corrections are scoped to the learning shell/components. */
.subject-page :is(a,button,input,select,textarea,summary):focus-visible{outline:3px solid var(--accent);outline-offset:3px}
.subject-page #lesson .section-nav button[aria-pressed="true"]{background:var(--accent);border-color:var(--accent);color:#fff}
.subject-page #lesson :is(.photo-atlas,.photo-lab) .overline{color:#e3f1dc}
.subject-page #lesson :is(.photo-atlas,.photo-lab) :is(button,input):focus-visible{outline-color:#fff}
.subject-page.physics #lesson .concept-visual #lesson-diagram{background:#102936;color:#dce8ff;border-radius:12px;padding:12px}
.subject-page.physics #lesson .concept-visual figure{margin:0}
.subject-page.physics #lesson .concept-visual figcaption{line-height:1.65;margin-top:12px}
.subject-page.physics #lesson .experiment{display:block;margin-top:20px;line-height:1.6}
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.subject-page.physics #lesson .experiment select{max-width:100%;min-height:44px;background:#fff;border:1px solid var(--line);border-radius:8px;padding:8px}
@media(max-width:560px){.subject-page #lesson > h2,.subject-page .heading h2{font-size:clamp(2rem,9vw,2.6rem);line-height:1.12;overflow-wrap:anywhere}}