.reader-hero,.reader-main{max-width:1200px;margin:0 auto;padding-left:60px;padding-right:60px}.reader-hero{padding-top:110px;padding-bottom:46px}.reader-hero h1{color:var(--white);max-width:820px;margin:14px 0}.reader-hero h1 em{color:var(--blue-lt);font-style:normal}.reader-hero p{max-width:720px;font-size:1.05rem;line-height:1.8}.reader-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:24px}.reader-main{padding-bottom:80px}.chapter-grid,.lab-grid-reader{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:24px 0 42px}.chapter-card,.lab-card-reader{display:block;background:var(--card-bg);border:1px solid var(--border);border-radius:var(--radius);padding:20px;color:var(--off-white)}.chapter-card:hover,.lab-card-reader:hover{background:var(--card-hover);color:var(--white)}.chapter-card strong,.lab-card-reader strong{display:block;color:var(--white);font-family:var(--font-display);font-size:1.12rem;margin-bottom:6px}.chapter-card span,.lab-card-reader span{display:block;color:var(--accent);font:600 .7rem var(--font-mono);letter-spacing:.1em;text-transform:uppercase;margin-bottom:8px}.reader-panel{background:#fff;color:#202a36;border-radius:var(--radius);padding:24px;margin-top:24px}.reader-panel h2{color:#202a36;margin-bottom:8px}.reader-panel p{color:#536273}.book-frame{width:100%;height:760px;border:1px solid #d8dee8;border-radius:var(--radius-sm);margin-top:18px}.reader-note{border-left:3px solid var(--accent);background:rgba(245,158,11,.07);padding:16px 20px;margin:22px 0}.reader-note p{color:var(--off-white);font-size:.9rem}.lab-content{display:grid;grid-template-columns:minmax(0,1fr) 280px;gap:24px}.lab-copy,.lab-side{background:var(--card-bg);border:1px solid var(--border);border-radius:var(--radius);padding:24px}.lab-copy h2,.lab-side h2{color:var(--white);margin-bottom:14px}.lab-copy p{margin-bottom:16px}.lab-side ul{list-style:none;display:grid;gap:12px}.lab-side li{color:var(--muted);font-size:.9rem}.lab-side strong{display:block;color:var(--off-white)}.reader-footer{max-width:1200px;margin:0 auto;padding:30px 60px 60px;border-top:1px solid var(--border);display:flex;justify-content:space-between;gap:20px;flex-wrap:wrap}@media(max-width:900px){.reader-hero,.reader-main{padding-left:24px;padding-right:24px}.reader-hero{padding-top:88px}.chapter-grid,.lab-grid-reader{grid-template-columns:1fr}.lab-content{grid-template-columns:1fr}.book-frame{height:620px}.reader-footer{padding:28px 24px 44px}}