/* Overview hub + chapter hubs — scoped Lehrbuch tokens (no global tokens.css). */
.lecture-page {
  --lecture-bg: #F6F5F1; --lecture-surface: #FAF8F2; --lecture-sunken: #EFEDE6;
  --lecture-ink-1: #1F2421; --lecture-ink-2: #4A4D48; --lecture-ink-3: #7A7D77; --lecture-ink-mute: #A7AAA3;
  --lecture-rule: #DDD9CF; --lecture-rule-strong: #C9C5B9; --lecture-accent: #DC3B55;
  --lecture-font: "Mona Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
}
@font-face { font-family: "Mona Sans"; src: url("../fonts/MonaSansVF_wght_opsz_.woff2") format("woff2"); font-weight: 100 900; font-style: normal; font-display: swap; }
* { box-sizing: border-box; }
body.lecture-page { margin: 0; background: var(--lecture-bg); color: var(--lecture-ink-1); font-family: var(--lecture-font); -webkit-font-smoothing: antialiased; }
.lecture-wrap { max-width: 1280px; margin: 0 auto; padding: 0 32px; }

/* header (redeclared so overview.css stands alone) */
.lecture-header { position: sticky; top: 0; z-index: 20; border-bottom: 1px solid var(--lecture-rule); background: rgba(250,248,242,.92); backdrop-filter: saturate(1.2) blur(8px); }
.lecture-header-inner { max-width: 1320px; margin: 0 auto; padding: 0 24px; height: 60px; display: flex; align-items: center; gap: 20px; }
.lecture-logo { display: flex; align-items: center; gap: 11px; text-decoration: none; color: var(--lecture-ink-1); min-width: 0; }
.lecture-logo img { display: block; flex: none; }
.lecture-book-title { font-weight: 700; font-size: 16px; letter-spacing: -.01em; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.lecture-toc { margin: 0 auto; position: relative; }
.lecture-toc-dropdown > summary { list-style: none; cursor: pointer; font-size: 15px; font-weight: 600; color: var(--lecture-ink-2); padding: 8px 14px; border-radius: 8px; border: 1px solid var(--lecture-rule); background: #fff; user-select: none; }
.lecture-toc-dropdown > summary::-webkit-details-marker { display: none; }
.lecture-toc-dropdown[open] > summary { border-color: var(--lecture-accent); color: var(--lecture-ink-1); }
.lecture-toc-dropdown ul { position: absolute; top: calc(100% + 8px); left: 50%; transform: translateX(-50%); margin: 0; padding: 8px; list-style: none; min-width: 340px; max-height: 70vh; overflow: auto; background: #fff; border: 1px solid var(--lecture-rule); border-radius: 12px; box-shadow: 0 18px 50px -24px rgba(31,36,33,.5); }
.lecture-toc-dropdown li a { display: block; padding: 9px 12px; border-radius: 8px; font-size: 14px; color: var(--lecture-ink-2); text-decoration: none; }
.lecture-toc-dropdown li a:hover { background: var(--lecture-bg); color: var(--lecture-ink-1); }
.lecture-toc-dropdown li a[aria-current="page"] { color: var(--lecture-accent); font-weight: 600; }
.lecture-escape { font-size: 14px; color: var(--lecture-ink-3); text-decoration: none; white-space: nowrap; }
.lecture-escape:hover { color: var(--lecture-accent); }
.lecture-crumbs { font-size: 13px; color: var(--lecture-ink-3); padding: 22px 0 0; }
.lecture-crumbs a { color: var(--lecture-ink-3); text-decoration: none; }
.lecture-crumbs a:hover { color: var(--lecture-accent); }
.lecture-crumbs .sep { margin: 0 8px; opacity: .6; }

/* hero */
.lecture-hero { padding: 56px 0 36px; border-bottom: 1px solid var(--lecture-rule); }
.lecture-hero .eyebrow { font-size: 14px; font-weight: 600; letter-spacing: .1em; text-transform: uppercase; color: var(--lecture-accent); margin-bottom: 16px; }
.lecture-hero h1 { margin: 0; font-size: clamp(34px, 5vw, 54px); font-weight: 700; line-height: 1.06; letter-spacing: -.025em; max-width: 900px; text-wrap: balance; }
.lecture-hero p { margin: 18px 0 0; font-size: clamp(17px, 2.4vw, 21px); line-height: 1.5; color: var(--lecture-ink-2); max-width: 740px; }
.lecture-hero .meta { display: flex; gap: 28px; margin-top: 24px; font-size: 15px; color: var(--lecture-ink-3); }
.lecture-hero .meta b { color: var(--lecture-ink-1); font-weight: 700; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.lecture-hero .cta { display: inline-flex; align-items: center; gap: 9px; text-decoration: none; font-size: 15px; font-weight: 600; padding: 12px 20px; border-radius: 11px; border: 1px solid var(--lecture-rule); background: #fff; color: var(--lecture-ink-1); transition: border-color .12s, transform .12s, background .12s; }
.lecture-hero .cta:hover { border-color: var(--lecture-accent); transform: translateY(-1px); }
.lecture-hero .cta.primary { background: var(--lecture-ink-1); border-color: var(--lecture-ink-1); color: #fff; }
.lecture-hero .cta.primary:hover { background: #000; border-color: #000; }
.chapter-hero { border-bottom: 1px solid var(--lecture-rule); }
.chapter-hero .meta { margin-top: 18px; font-size: 15px; color: var(--lecture-ink-3); }
.chapter-hero .meta b { color: var(--lecture-ink-1); }

/* chapter section + grid */
.lecture-chapter { padding: 44px 0 4px; scroll-margin-top: 76px; }
.chapter-head { display: flex; align-items: baseline; gap: 16px; margin-bottom: 22px; }
.chapter-head .knum { font-size: 15px; font-weight: 700; color: var(--lecture-accent); letter-spacing: .04em; text-decoration: none; }
.chapter-head .knum:hover { text-decoration: underline; }
.chapter-head h2 { margin: 0; font-size: clamp(22px, 3vw, 30px); font-weight: 700; letter-spacing: -.015em; }
.chapter-head .count { font-size: 14px; color: var(--lecture-ink-mute); margin-left: auto; }
.lecture-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 18px; }
@media (max-width: 1080px) { .lecture-grid { grid-template-columns: repeat(3, 1fr); } }
@media (max-width: 640px) { .lecture-grid { grid-template-columns: repeat(2, 1fr); } .lecture-toc, .lecture-crumbs { display: none; } }
.lecture-thumb { text-decoration: none; color: inherit; display: flex; flex-direction: column; gap: 9px; }
.lecture-thumb .frame { position: relative; aspect-ratio: 1920 / 1080; border: 1px solid var(--lecture-rule); border-radius: 9px; overflow: hidden; background: var(--lecture-surface); transition: border-color .12s, transform .12s, box-shadow .12s; }
.lecture-thumb:hover .frame { border-color: var(--lecture-accent); transform: translateY(-2px); box-shadow: 0 12px 26px -16px rgba(31,36,33,.5); }
.lecture-thumb .frame img { width: 100%; height: 100%; object-fit: cover; display: block; }
.lecture-thumb .frame .n { position: absolute; left: 8px; top: 8px; background: rgba(31,36,33,.78); color: #fff; font-size: 12px; font-weight: 600; padding: 2px 8px; border-radius: 6px; font-variant-numeric: tabular-nums; }
.lecture-thumb .cap { font-size: 14px; line-height: 1.35; color: var(--lecture-ink-2); font-weight: 500; }
.lecture-thumb.divider-thumb .frame { border-color: var(--lecture-rule-strong); }
.lecture-thumb.divider-thumb .cap { color: var(--lecture-accent); font-weight: 600; }

.lecture-footer { max-width: 1280px; margin: 48px auto 0; padding: 32px; border-top: 1px solid var(--lecture-rule); display: flex; flex-wrap: wrap; gap: 12px; justify-content: space-between; align-items: center; font-size: 14px; color: var(--lecture-ink-3); }
.lecture-footer a { color: var(--lecture-ink-3); text-decoration: none; }
.lecture-footer a:hover { color: var(--lecture-accent); }