:root {
  --primary: #123b5d;
  --primary-2: #1f6f8b;
  --accent: #3aa6a0;
  --ink: #17212b;
  --muted: #637381;
  --surface: #f6f9fb;
  --border: #dfe7ec;
}
html { scroll-behavior: smooth; }
body { color: var(--ink); background: #fff; font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; }
a { color: var(--primary-2); }
.navbar { background: rgba(255,255,255,.96); backdrop-filter: blur(8px); border-bottom: 1px solid var(--border); }
.brand-mark { width: 40px; height: 40px; border-radius: 10px; display:inline-flex; align-items:center; justify-content:center; background: var(--primary); color:#fff; font-weight:800; letter-spacing:-.04em; }
.brand-name { font-weight: 800; letter-spacing: -.02em; color: var(--primary); }
.hero { background: linear-gradient(135deg, #f3f8fb 0%, #ffffff 58%, #eef8f7 100%); padding: 7rem 0 6rem; border-bottom: 1px solid var(--border); }
.eyebrow { color: var(--primary-2); text-transform: uppercase; letter-spacing: .14em; font-weight: 700; font-size: .78rem; }
.display-title { color: var(--primary); font-weight: 800; letter-spacing: -.045em; }
.section { padding: 5rem 0; }
.section-alt { background: var(--surface); }
.card-clean { border: 1px solid var(--border); border-radius: 18px; box-shadow: 0 12px 35px rgba(18,59,93,.06); }
.book-cover { min-height: 430px; border-radius: 14px; padding: 2rem; color:#fff; background: radial-gradient(circle at 75% 20%, rgba(58,166,160,.8), transparent 25%), linear-gradient(145deg, #0c2f4a, #1f6f8b 55%, #123b5d); position: relative; overflow:hidden; display:flex; flex-direction:column; justify-content:space-between; box-shadow: 0 20px 45px rgba(18,59,93,.2); }
.book-cover::after { content:""; position:absolute; width:240px; height:240px; border:1px solid rgba(255,255,255,.18); border-radius:50%; right:-90px; bottom:-90px; box-shadow:0 0 0 30px rgba(255,255,255,.04),0 0 0 60px rgba(255,255,255,.03); }
.book-cover .cover-content { position:relative; z-index:1; }
.book-cover h2 { font-weight:800; line-height:1.08; letter-spacing:-.035em; }
.book-cover .cover-rule { width:55px; height:4px; background:#8ed8d1; border-radius:4px; margin:1.2rem 0; }
.book-cover .cover-small { font-size:.78rem; letter-spacing:.12em; text-transform:uppercase; opacity:.8; }
.badge-soft { background:#e8f4f4; color:#17655f; font-weight:600; }
.btn-primary { --bs-btn-bg: var(--primary); --bs-btn-border-color: var(--primary); --bs-btn-hover-bg: #0d2d46; --bs-btn-hover-border-color:#0d2d46; }
.btn-outline-primary { --bs-btn-color: var(--primary); --bs-btn-border-color: var(--primary); --bs-btn-hover-bg: var(--primary); --bs-btn-hover-border-color:var(--primary); }
.icon-box { width:48px; height:48px; display:flex; align-items:center; justify-content:center; border-radius:12px; background:#eaf4f8; color:var(--primary); font-size:1.2rem; }
.breadcrumb a { text-decoration:none; }
.book-meta dt { color:var(--muted); font-weight:600; }
.book-meta dd { font-weight:650; margin-bottom:1rem; }
.chapter-list .list-group-item { border-color: var(--border); padding: 1rem 1.1rem; }
.footer { background:#102b3e; color:#cbd8e0; }
.footer a { color:#e6f1f5; text-decoration:none; }
.footer .brand-name { color:#fff; }
.small-caps { text-transform:uppercase; letter-spacing:.1em; font-size:.75rem; font-weight:700; }
@media (max-width: 767.98px) { .hero { padding: 5rem 0 4rem; } .book-cover { min-height: 380px; } .section { padding:4rem 0; } }