.lesson-page{padding:30px 0 60px}.lesson-hero{background:linear-gradient(135deg,#eef7fa,#f8fbfc);border-bottom:1px solid #dce7ec;padding:32px 0}.lesson-hero h1{margin:9px 0 10px;font-size:38px;color:#153449}.lesson-hero p{max-width:850px;line-height:1.65}.lesson-meta{display:flex;gap:8px;flex-wrap:wrap;margin-top:15px}.lesson-meta span{padding:7px 10px;border-radius:999px;background:#fff;border:1px solid #d9e6ec;font-size:11px;font-weight:800}.content-card{background:#fff;border:1px solid #d9e6ec;border-radius:20px;padding:24px;margin:18px 0;box-shadow:0 9px 24px rgba(18,52,73,.04)}.content-card h2{margin-top:0;color:#153449}.content-card h3{color:#1f5f8b}.content-card p,.content-card li{line-height:1.7}.study-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.study-box{background:#f6fafb;border:1px solid #dce8ed;border-radius:15px;padding:16px}.study-box h3{margin-top:0}.note{background:#edf9f4;border-left:5px solid #2d9c7a;padding:15px;border-radius:12px}.warning-note{background:#fff7e8;border-left:5px solid #e0a22b;padding:15px;border-radius:12px}.mini-test{display:grid;gap:12px}.q{background:#f8fbfc;border:1px solid #dce8ed;border-radius:14px;padding:15px}.nav-end{display:flex;justify-content:space-between;gap:10px;margin-top:24px}.nav-end a{padding:12px 16px;border-radius:11px;text-decoration:none;font-weight:900}.nav-end .back{background:#eef3f6;color:#153449}.nav-end .next{background:#1f5f8b;color:#fff}@media(max-width:750px){.study-grid{grid-template-columns:1fr}.nav-end{flex-direction:column}}