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:root{color-scheme:dark;--bg:#081b27;--card:#102b3a;--line:#284759;--ink:#f3f1e8;--soft:#b0c8d1;--mint:#91deca;--gold:#f5c66c;--red:#f0a08d}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:17px/1.6 'Segoe UI',sans-serif}a{color:var(--mint);text-underline-offset:4px}button,input,select,textarea{font:inherit}button,select{cursor:pointer}button{border:1px solid #567585;background:#203d4d;color:var(--ink);padding:.7rem 1.1rem;border-radius:10px}button:hover{background:#315363}button:disabled{opacity:.45;cursor:default}button.primary{background:var(--mint);color:#072832;border-color:var(--mint);font-weight:650}input,select,textarea{background:#091f2b;color:var(--ink);border:1px solid #5b7a89;border-radius:8px;padding:.65rem;width:100%}textarea{resize:vertical;min-height:4em}label{display:block;margin:.55rem 0;color:var(--soft)}:focus-visible{outline:3px solid var(--gold);outline-offset:4px}.skip{position:absolute;left:-10000px}.skip:focus{left:12px;top:10px;background:var(--bg);z-index:20}header{max-width:1700px;margin:auto;padding:25px 4%;display:flex;justify-content:space-between;gap:24px;border-bottom:1px solid var(--line)}header nav{display:flex;gap:24px;align-items:center;flex-wrap:wrap}.brand{text-decoration:none;font-size:27px;font-weight:750;color:var(--ink)}.brand span{font-size:10px;letter-spacing:.13em;display:block;color:var(--mint)}main{max-width:1700px;margin:auto;padding:0 4%}.hero{padding:62px 0 45px;max-width:1040px}.hero h1{font-size:clamp(38px,4.4vw,72px);line-height:1.1;letter-spacing:-.04em;margin:10px 0 22px}.hero h1 em{font-style:normal;color:var(--mint)}.hero>p:not(.eyebrow):not(.small){font-size:21px;max-width:770px;color:var(--soft)}.eyebrow{font-size:12px;letter-spacing:.12em;font-weight:750;color:var(--mint);margin:0 0 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16px}.section-head{display:flex;justify-content:space-between;gap:20px;align-items:flex-start}.help-select{font-size:12px;min-width:180px;margin:0}.help-select select{font-size:13px}.feedback{padding:13px 17px;background:#082330;border-left:3px solid var(--mint);min-height:52px}.feedback.error{border-color:var(--red)}.hint{color:var(--soft)}.fields{display:grid;grid-template-columns:1fr 1fr;gap:18px}.proof{border-left:3px solid var(--gold);padding-left:17px}.notice{padding:18px;border:1px solid var(--gold);border-radius:10px;color:var(--gold)}.lesson-navigation{display:flex;justify-content:space-between;gap:15px;margin:28px 0 50px}.actions{display:flex;gap:10px;flex-wrap:wrap;margin:15px 0}.experiment-card{background:#0b2330;border-radius:13px;padding:22px;margin:12px 0;border:1px solid var(--line)}.object-row{display:flex;gap:24px;align-items:center}.object-row 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nav{font-size:14px}.section-head{display:block}.help-select{max-width:260px;margin-bottom:15px}}@media(max-width:760px){header{display:block}header nav{gap:12px;margin-top:18px}.hero{padding-top:35px}.course-layout{display:block}.curriculum{margin-bottom:30px}#course-list{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px}.lesson-item{font-size:12px;padding:10px}.hour-list h3{font-size:11px}.fields,.trace{grid-template-columns:1fr}.predict,.practice,.transfer{padding:19px}.object-row{align-items:flex-start}.object-row img{width:100px;height:100px}.film-meta{font-size:12px}.lesson-navigation button{font-size:14px}h3{font-size:21px}.test-table{font-size:13px}.test-table td,.test-table th{padding:5px}}@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}}

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