/* 高效訓練科學系統｜實證擴充版 */

:root {
  color-scheme: light dark;

  --bg: #f4f6f9;
  --bg-elev: #ffffff;
  --bg-sunken: #eceff4;
  --ink: #14171c;
  --ink-2: #454c59;
  --ink-3: #6d7686;
  --line: #dde2ea;
  --line-2: #eaeef4;

  --brand: #3d4ee8;
  --brand-ink: #2c39c4;
  --brand-soft: #eceefe;
  --accent: #b4530a;
  --accent-soft: #fdf0e2;
  --warn: #a8322d;
  --warn-soft: #fdedec;
  --ok: #1d7a52;
  --ok-soft: #e6f5ee;

  --radius: 14px;
  --radius-sm: 9px;
  --shadow: 0 1px 2px rgba(18, 24, 40, .05), 0 8px 24px -14px rgba(18, 24, 40, .18);
  --shadow-lg: 0 2px 6px rgba(18, 24, 40, .06), 0 24px 48px -24px rgba(18, 24, 40, .28);

  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans TC",
    "PingFang TC", "Microsoft JhengHei", sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, monospace;

  --sidebar-w: 286px;
  --topbar-h: 58px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1015;
    --bg-elev: #161a21;
    --bg-sunken: #11151b;
    --ink: #e7eaf0;
    --ink-2: #b3bbc9;
    --ink-3: #838d9d;
    --line: #262c36;
    --line-2: #1e242c;

    --brand: #8b95ff;
    --brand-ink: #a8b0ff;
    --brand-soft: #1b1f38;
    --accent: #e5a25f;
    --accent-soft: #2a2117;
    --warn: #f0918b;
    --warn-soft: #2c1a1a;
    --ok: #63c79b;
    --ok-soft: #12251d;

    --shadow: 0 1px 2px rgba(0, 0, 0, .4), 0 8px 24px -14px rgba(0, 0, 0, .7);
    --shadow-lg: 0 2px 6px rgba(0, 0, 0, .45), 0 24px 48px -24px rgba(0, 0, 0, .8);
  }
}

:root[data-theme="light"] {
  color-scheme: light;
  --bg: #f4f6f9; --bg-elev: #fff; --bg-sunken: #eceff4;
  --ink: #14171c; --ink-2: #454c59; --ink-3: #6d7686;
  --line: #dde2ea; --line-2: #eaeef4;
  --brand: #3d4ee8; --brand-ink: #2c39c4; --brand-soft: #eceefe;
  --accent: #b4530a; --accent-soft: #fdf0e2;
  --warn: #a8322d; --warn-soft: #fdedec;
  --ok: #1d7a52; --ok-soft: #e6f5ee;
  --shadow: 0 1px 2px rgba(18,24,40,.05), 0 8px 24px -14px rgba(18,24,40,.18);
  --shadow-lg: 0 2px 6px rgba(18,24,40,.06), 0 24px 48px -24px rgba(18,24,40,.28);
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0d1015; --bg-elev: #161a21; --bg-sunken: #11151b;
  --ink: #e7eaf0; --ink-2: #b3bbc9; --ink-3: #838d9d;
  --line: #262c36; --line-2: #1e242c;
  --brand: #8b95ff; --brand-ink: #a8b0ff; --brand-soft: #1b1f38;
  --accent: #e5a25f; --accent-soft: #2a2117;
  --warn: #f0918b; --warn-soft: #2c1a1a;
  --ok: #63c79b; --ok-soft: #12251d;
  --shadow: 0 1px 2px rgba(0,0,0,.4), 0 8px 24px -14px rgba(0,0,0,.7);
  --shadow-lg: 0 2px 6px rgba(0,0,0,.45), 0 24px 48px -24px rgba(0,0,0,.8);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--topbar-h) + 16px); }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }

h1, h2, h3, h4 { line-height: 1.32; margin: 0; font-weight: 700; letter-spacing: -.01em; }

/* ── Topbar ─────────────────────────────── */
.topbar {
  position: sticky; top: 0; z-index: 60;
  height: var(--topbar-h);
  display: flex; align-items: center; gap: 14px;
  padding: 0 18px;
  background: color-mix(in srgb, var(--bg-elev) 88%, transparent);
  backdrop-filter: saturate(160%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.topbar .mark {
  font-weight: 800; font-size: 15px; letter-spacing: -.02em;
  display: flex; align-items: center; gap: 9px; white-space: nowrap;
}
.mark .dot {
  width: 22px; height: 22px; border-radius: 7px; flex: none;
  background: linear-gradient(140deg, var(--brand), #7f5bf0);
  display: grid; place-items: center; color: #fff; font-size: 12px;
}
.topbar .spacer { flex: 1; }

.progress-wrap { display: flex; align-items: center; gap: 9px; font-size: 12.5px; color: var(--ink-3); }
.progress-track { width: 108px; height: 6px; border-radius: 99px; background: var(--bg-sunken); overflow: hidden; border: 1px solid var(--line-2); }
.progress-bar { height: 100%; width: 0; background: linear-gradient(90deg, var(--brand), #7f5bf0); transition: width .35s ease; }

.icon-btn {
  border: 1px solid var(--line); background: var(--bg-elev); color: var(--ink-2);
  border-radius: 9px; height: 34px; min-width: 34px; padding: 0 9px;
  cursor: pointer; font-size: 14px; font-family: inherit;
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
}
.icon-btn:hover { border-color: var(--brand); color: var(--brand); }
.menu-btn { display: none; }

/* ── Shell ──────────────────────────────── */
.shell { display: flex; align-items: flex-start; max-width: 1440px; margin: 0 auto; }

.sidebar {
  position: sticky; top: var(--topbar-h);
  width: var(--sidebar-w); flex: none;
  height: calc(100vh - var(--topbar-h));
  overflow-y: auto; padding: 20px 12px 60px 18px;
  border-right: 1px solid var(--line);
}
.sidebar h4 {
  font-size: 11px; text-transform: uppercase; letter-spacing: .09em;
  color: var(--ink-3); margin: 16px 0 8px 8px; font-weight: 700;
}
.sidebar h4:first-child { margin-top: 0; }

.nav-item {
  display: flex; gap: 9px; align-items: baseline;
  padding: 7px 10px; border-radius: var(--radius-sm);
  color: var(--ink-2); font-size: 13.5px; line-height: 1.5;
  border-left: 2px solid transparent;
}
.nav-item:hover { background: var(--bg-sunken); text-decoration: none; color: var(--ink); }
.nav-item.active { background: var(--brand-soft); color: var(--brand-ink); border-left-color: var(--brand); font-weight: 600; }
.nav-item .n { font-family: var(--mono); font-size: 11px; color: var(--ink-3); flex: none; width: 32px; }
.nav-item.active .n { color: var(--brand-ink); }
.nav-item .done { margin-left: auto; color: var(--ok); font-size: 12px; opacity: 0; }
.nav-item.is-done .done { opacity: 1; }

.content { flex: 1; min-width: 0; padding: 0 clamp(16px, 3.4vw, 52px) 100px; }

/* ── Hero ───────────────────────────────── */
.hero { padding: 52px 0 34px; border-bottom: 1px solid var(--line); }
.eyebrow {
  display: inline-flex; align-items: center; gap: 7px;
  font-size: 12px; font-weight: 650; letter-spacing: .02em;
  color: var(--brand-ink); background: var(--brand-soft);
  padding: 5px 11px; border-radius: 99px; margin-bottom: 18px;
}
.hero h1 { font-size: clamp(30px, 4.6vw, 46px); letter-spacing: -.03em; }
.hero .tagline { font-size: clamp(16px, 1.6vw, 19px); color: var(--ink-2); margin: 14px 0 0; max-width: 62ch; }

.statline { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 26px; }
.stat {
  background: var(--bg-elev); border: 1px solid var(--line);
  border-radius: var(--radius-sm); padding: 10px 15px; min-width: 96px;
}
.stat b { display: block; font-size: 21px; letter-spacing: -.02em; line-height: 1.2; }
.stat span { font-size: 11.5px; color: var(--ink-3); }

.sourcebox {
  margin-top: 26px; background: var(--bg-elev); border: 1px solid var(--line);
  border-left: 3px solid var(--accent); border-radius: var(--radius-sm);
  padding: 14px 18px; font-size: 13.5px; color: var(--ink-2);
}
.sourcebox b { color: var(--ink); }

/* ── Sections ───────────────────────────── */
section { scroll-margin-top: calc(var(--topbar-h) + 12px); }
.method { padding: 42px 0; border-bottom: 1px solid var(--line); }
.method > h2 { font-size: 26px; letter-spacing: -.02em; }
.method > p { color: var(--ink-2); max-width: 72ch; margin: 12px 0 0; }

.method-grid { display: grid; gap: 14px; grid-template-columns: repeat(auto-fit, minmax(255px, 1fr)); margin-top: 24px; }
.method-card { background: var(--bg-elev); border: 1px solid var(--line); border-radius: var(--radius); padding: 17px 19px; }
.method-card h3 { font-size: 15px; margin-bottom: 7px; }
.method-card p { margin: 0; font-size: 13.5px; color: var(--ink-2); line-height: 1.7; }

.grades { margin-top: 22px; display: flex; flex-wrap: wrap; gap: 8px; }
.grade { font-size: 12.5px; border: 1px solid var(--line); border-radius: 99px; padding: 5px 13px; background: var(--bg-elev); color: var(--ink-2); }
.grade b { color: var(--ink); }

/* ── Chapter ────────────────────────────── */
.chapter { padding: 46px 0; border-bottom: 1px solid var(--line); }
.ch-head { display: flex; align-items: flex-start; gap: 16px; flex-wrap: wrap; }
.ch-no {
  font-family: var(--mono); font-size: 12px; font-weight: 700;
  color: #fff; background: var(--brand); padding: 4px 10px; border-radius: 7px;
  flex: none; margin-top: 5px; letter-spacing: .02em;
}
.chapter[data-kind="ext"] .ch-no { background: var(--accent); }
.chapter[data-kind="map"] .ch-no { background: var(--ink-3); }
.ch-title { flex: 1; min-width: 240px; }
.ch-title h2 { font-size: clamp(21px, 2.5vw, 27px); letter-spacing: -.025em; }
.ch-title .lede { color: var(--ink-2); margin: 10px 0 0; font-size: 15.5px; max-width: 68ch; }

.done-btn {
  border: 1px solid var(--line); background: var(--bg-elev); color: var(--ink-3);
  border-radius: 99px; padding: 6px 14px; font-size: 12.5px; cursor: pointer;
  font-family: inherit; white-space: nowrap; margin-top: 4px;
}
.done-btn:hover { border-color: var(--ok); color: var(--ok); }
.done-btn[aria-pressed="true"] { background: var(--ok-soft); border-color: var(--ok); color: var(--ok); font-weight: 600; }

.origin {
  margin-top: 20px; background: var(--bg-sunken); border: 1px solid var(--line-2);
  border-radius: var(--radius-sm); padding: 12px 16px; font-size: 13px; color: var(--ink-2);
}
.origin b { color: var(--ink); font-size: 12px; letter-spacing: .02em; }
.origin ul { margin: 7px 0 0; padding-left: 18px; }
.origin li { margin: 2px 0; }

.goals { margin-top: 18px; }
.goals b { font-size: 12px; letter-spacing: .04em; text-transform: uppercase; color: var(--ink-3); }
.goals ol { margin: 8px 0 0; padding-left: 20px; color: var(--ink-2); font-size: 14.5px; }
.goals li { margin: 4px 0; }

/* ── Video ──────────────────────────────── */
.videos { margin-top: 28px; display: grid; gap: 20px; }
.video-card { background: var(--bg-elev); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); }

.frame { position: relative; aspect-ratio: 16 / 9; background: #000; }
.frame iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.frame .poster {
  position: absolute; inset: 0; width: 100%; height: 100%;
  border: 0; padding: 0; cursor: pointer; background-size: cover; background-position: center;
  display: grid; place-items: center;
}
.frame .poster::after {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(180deg, rgba(0,0,0,.05), rgba(0,0,0,.45));
}
.frame .play {
  position: relative; z-index: 1;
  width: 66px; height: 46px; border-radius: 12px;
  background: rgba(220, 34, 34, .93); display: grid; place-items: center;
  box-shadow: 0 6px 20px rgba(0,0,0,.4); transition: transform .18s ease;
}
.frame .play svg { width: 24px; height: 24px; fill: #fff; }
.frame .poster:hover .play { transform: scale(1.09); background: #f00; }

.v-body { padding: 15px 19px 18px; }
.v-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; margin-bottom: 8px; }
.v-role {
  font-size: 11px; font-weight: 700; letter-spacing: .04em;
  padding: 3px 9px; border-radius: 6px; background: var(--brand-soft); color: var(--brand-ink);
}
.v-role.alt { background: var(--bg-sunken); color: var(--ink-3); }
.v-chan { font-size: 12.5px; color: var(--ink-3); }
.v-stats { margin-left: auto; display: flex; gap: 12px; font-size: 12px; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.v-stats span { display: inline-flex; align-items: center; gap: 4px; }

.v-title { font-size: 15.5px; font-weight: 650; margin: 0 0 10px; }
.v-title a { color: var(--ink); }

.why { background: var(--brand-soft); border-radius: var(--radius-sm); padding: 12px 15px; font-size: 13.8px; color: var(--ink-2); line-height: 1.72; }
.why b { color: var(--brand-ink); display: block; font-size: 11.5px; letter-spacing: .05em; text-transform: uppercase; margin-bottom: 5px; }
.why strong { color: var(--ink); }

/* ── Evidence ───────────────────────────── */
.block-h {
  margin: 34px 0 14px; font-size: 13px; font-weight: 700;
  letter-spacing: .06em; text-transform: uppercase; color: var(--ink-3);
  display: flex; align-items: center; gap: 10px;
}
.block-h::after { content: ""; flex: 1; height: 1px; background: var(--line); }

.ev-grid { display: grid; gap: 13px; }
.ev {
  background: var(--bg-elev); border: 1px solid var(--line);
  border-left: 3px solid var(--ok); border-radius: var(--radius-sm); padding: 15px 18px;
}
.ev-top { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin-bottom: 7px; }
.ev-type {
  font-size: 11px; font-weight: 700; padding: 2px 8px; border-radius: 5px;
  background: var(--ok-soft); color: var(--ok); letter-spacing: .02em;
}
.ev-xref { font-size: 11px; color: var(--ink-3); border: 1px dashed var(--line); padding: 2px 8px; border-radius: 5px; }
.ev h4 { font-size: 15px; }
.ev .cite { font-size: 12.5px; color: var(--ink-3); margin: 5px 0 10px; font-style: italic; }
.ev .finding { font-size: 14px; color: var(--ink); margin: 0 0 9px; line-height: 1.72; }
.ev .teaches { font-size: 13.2px; color: var(--ink-2); margin: 0; padding-left: 12px; border-left: 2px solid var(--line); }
.ev .teaches b { color: var(--ink-2); }
.ids { display: flex; flex-wrap: wrap; gap: 7px; margin-top: 11px; }
.id-pill {
  font-family: var(--mono); font-size: 11.5px; padding: 3px 9px;
  border: 1px solid var(--line); border-radius: 6px; color: var(--ink-2); background: var(--bg-sunken);
}
.id-pill:hover { border-color: var(--brand); color: var(--brand); text-decoration: none; }
.id-pill.none { color: var(--ink-3); border-style: dashed; }

/* ── Practice / pitfalls ────────────────── */
.two-col { display: grid; gap: 14px; grid-template-columns: repeat(auto-fit, minmax(290px, 1fr)); margin-top: 30px; }
.panel { border-radius: var(--radius-sm); padding: 15px 18px; border: 1px solid var(--line); }
.panel h4 { font-size: 13px; letter-spacing: .04em; text-transform: uppercase; margin-bottom: 9px; }
.panel ul { margin: 0; padding-left: 19px; font-size: 14px; line-height: 1.75; }
.panel li { margin: 6px 0; }
.panel.do { background: var(--ok-soft); border-color: color-mix(in srgb, var(--ok) 32%, transparent); }
.panel.do h4 { color: var(--ok); }
.panel.dont { background: var(--warn-soft); border-color: color-mix(in srgb, var(--warn) 32%, transparent); }
.panel.dont h4 { color: var(--warn); }

/* ── 觀看紀錄 ───────────────────────────── */
.ch-actions { display: flex; align-items: center; gap: 10px; margin-top: 4px; flex-wrap: wrap; }
.watch-count {
  font-size: 12px; color: var(--ink-3); font-variant-numeric: tabular-nums;
  border: 1px solid var(--line); border-radius: 99px; padding: 5px 12px; background: var(--bg-elev);
}
.watch-count.full { color: var(--ok); border-color: color-mix(in srgb, var(--ok) 40%, transparent); background: var(--ok-soft); }

.video-card.is-watched { border-color: color-mix(in srgb, var(--ok) 40%, transparent); }
.video-card.is-watched .frame::after {
  content: "看過"; position: absolute; z-index: 2; top: 10px; left: 10px;
  font-size: 11px; font-weight: 700; letter-spacing: .04em;
  background: var(--ok); color: #fff; padding: 3px 9px; border-radius: 6px;
  box-shadow: 0 2px 8px rgba(0,0,0,.35);
}

.v-tools { display: flex; gap: 8px; margin-top: 12px; flex-wrap: wrap; }
.watch-btn, .note-toggle, .stamp-btn {
  font-family: inherit; font-size: 12.5px; cursor: pointer;
  border: 1px solid var(--line); background: var(--bg-elev); color: var(--ink-2);
  border-radius: 99px; padding: 5px 13px; white-space: nowrap;
}
.watch-btn:hover, .note-toggle:hover, .stamp-btn:hover { border-color: var(--brand); color: var(--brand); }
.watch-btn[aria-pressed="true"] {
  background: var(--ok-soft); border-color: var(--ok); color: var(--ok); font-weight: 600;
}

/* ── 筆記 ───────────────────────────────── */
.note {
  margin-top: 14px; background: var(--bg-sunken);
  border: 1px solid var(--line-2); border-radius: var(--radius-sm); padding: 13px 15px;
}
.chapter > .note { margin-top: 0; background: var(--bg-elev); border-color: var(--line); padding: 16px 18px; }
.note-head { display: flex; align-items: center; gap: 10px; margin-bottom: 9px; flex-wrap: wrap; }
.note-head b { font-size: 12px; letter-spacing: .04em; color: var(--ink-3); text-transform: uppercase; }
.note-status { font-size: 11.5px; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.note-head .stamp-btn { margin-left: auto; }

.note-input {
  width: 100%; display: block; resize: vertical;
  font-family: inherit; font-size: 14.5px; line-height: 1.75; color: var(--ink);
  background: var(--bg-elev); border: 1px solid var(--line);
  border-radius: var(--radius-sm); padding: 11px 13px;
}
.note.compact .note-input { background: var(--bg-elev); }
.note-input:focus { outline: 2px solid color-mix(in srgb, var(--brand) 55%, transparent); outline-offset: 1px; border-color: var(--brand); }
.note-input::placeholder { color: var(--ink-3); }

.marks { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 9px; }
.marks:empty { display: none; }
.mark {
  font-family: var(--mono); font-size: 11.5px; cursor: pointer;
  border: 1px solid color-mix(in srgb, var(--brand) 40%, transparent);
  background: var(--brand-soft); color: var(--brand-ink);
  border-radius: 6px; padding: 3px 9px;
}
.mark:hover { background: var(--brand); color: #fff; }

/* ── 學習紀錄頁 ─────────────────────────── */
.notebook { padding: 46px 0; }
.notebook > h2 { font-size: clamp(24px, 3vw, 30px); letter-spacing: -.025em; }
.nb-lede { color: var(--ink-2); max-width: 70ch; margin: 12px 0 0; font-size: 15px; }
.nb-lede strong { color: var(--ink); }

.nb-actions { display: flex; flex-wrap: wrap; gap: 9px; margin: 22px 0 30px; }
.nb-actions .icon-btn { height: 36px; padding: 0 14px; font-size: 13px; }
.icon-btn.danger { color: var(--warn); border-color: color-mix(in srgb, var(--warn) 35%, transparent); }
.icon-btn.danger:hover { background: var(--warn-soft); border-color: var(--warn); color: var(--warn); }

/* ── 跨裝置同步 ─────────────────────────── */
#cloud-chip[data-state="ok"] { color: var(--ok); border-color: color-mix(in srgb, var(--ok) 45%, transparent); }
#cloud-chip[data-state="syncing"] { color: var(--brand); border-color: color-mix(in srgb, var(--brand) 45%, transparent); }
#cloud-chip[data-state="error"] { color: var(--warn); border-color: color-mix(in srgb, var(--warn) 45%, transparent); }
#cloud-chip { max-width: 170px; white-space: nowrap; gap: 5px; }
#cloud-chip .cloud-label { overflow: hidden; text-overflow: ellipsis; max-width: 120px; }

.cloud-card {
  background: var(--bg-elev); border: 1px solid var(--line);
  border-left: 3px solid var(--brand); border-radius: var(--radius);
  padding: 18px 20px; margin: 22px 0 26px;
}
.cloud-card > h3 { font-size: 15px; margin-bottom: 12px; }
.cloud-lede { margin: 0 0 14px; font-size: 13.8px; color: var(--ink-2); line-height: 1.7; max-width: 66ch; }
.cloud-lede strong { color: var(--ink); }

.cloud-grid { display: grid; gap: 11px; grid-template-columns: repeat(auto-fit, minmax(185px, 1fr)); }
.cloud-grid label { display: block; font-size: 12px; color: var(--ink-3); }
.cloud-grid input {
  width: 100%; margin-top: 4px; padding: 9px 11px; font-size: 15px; font-family: inherit;
  color: var(--ink); background: var(--bg-sunken);
  border: 1px solid var(--line); border-radius: var(--radius-sm);
}
.cloud-grid input:focus { outline: 2px solid color-mix(in srgb, var(--brand) 55%, transparent); outline-offset: 1px; border-color: var(--brand); }

.cloud-btns { display: flex; flex-wrap: wrap; gap: 9px; margin-top: 15px; }
.icon-btn.primary { background: var(--brand); border-color: var(--brand); color: #fff; font-weight: 600; }
.icon-btn.primary:hover { background: var(--brand-ink); border-color: var(--brand-ink); color: #fff; }

.cloud-msg { margin-top: 11px; font-size: 13px; color: var(--ink-2); }
.cloud-msg.bad { color: var(--warn); }
.cloud-msg:empty { display: none; }

.cloud-in { display: flex; flex-wrap: wrap; gap: 14px; align-items: center; }
.cloud-who b { display: block; font-size: 15px; }
.cloud-who span { font-size: 12.5px; color: var(--ink-3); font-family: var(--mono); }
.cloud-state { font-size: 12.5px; color: var(--ok); }
.cloud-in .cloud-btns { margin: 0 0 0 auto; }

.nb-stats { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 26px; }
.nb-stats .stat { min-width: 120px; }

.nb-empty {
  background: var(--bg-elev); border: 1px dashed var(--line);
  border-radius: var(--radius); padding: 26px; color: var(--ink-3); font-size: 14.5px;
}

.nb-entry {
  background: var(--bg-elev); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 18px 20px; margin-bottom: 14px;
}
.nb-entry h3 { font-size: 16px; margin-bottom: 10px; }
.nb-entry h3 a { color: var(--ink); }
.nb-text {
  margin: 0; font-family: inherit; font-size: 14.5px; line-height: 1.78;
  color: var(--ink-2); white-space: pre-wrap; word-break: break-word;
  border-left: 2px solid var(--line); padding-left: 13px;
}
.nb-video { margin-top: 14px; padding-top: 13px; border-top: 1px solid var(--line-2); }
.nb-vtitle { font-size: 13.5px; margin-bottom: 7px; display: flex; flex-wrap: wrap; gap: 8px; align-items: baseline; }
.nb-vtitle a { font-weight: 600; }
.nb-vtitle span { color: var(--ink-3); font-size: 12px; }

/* ── Pager ──────────────────────────────── */
.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 34px; }
.page-link {
  display: flex; flex-direction: column; gap: 3px;
  border: 1px solid var(--line); background: var(--bg-elev);
  border-radius: var(--radius-sm); padding: 13px 17px; min-height: 62px;
}
.page-link:hover { border-color: var(--brand); text-decoration: none; }
.page-link.next { text-align: right; }
.page-link .dir { font-size: 11.5px; color: var(--ink-3); letter-spacing: .03em; }
.page-link .t { font-size: 14px; font-weight: 600; color: var(--ink); }
.page-link.ghost { border: 0; background: none; pointer-events: none; }

/* ── Refs + comments ────────────────────── */
.tail { padding: 46px 0 0; }
.tail h2 { font-size: 24px; letter-spacing: -.02em; }
.tail p { color: var(--ink-2); max-width: 72ch; }

.giscus-wrap { margin-top: 22px; background: var(--bg-elev); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px; min-height: 140px; }
.giscus-hint {
  font-size: 13.2px; color: var(--ink-2); background: var(--accent-soft);
  border: 1px dashed color-mix(in srgb, var(--accent) 45%, transparent);
  border-radius: var(--radius-sm); padding: 14px 17px;
}
.giscus-hint b { color: var(--ink); }
.giscus-hint code { font-family: var(--mono); font-size: 12px; background: var(--bg-sunken); padding: 1px 5px; border-radius: 4px; }
.giscus-hint ol { padding-left: 20px; margin: 8px 0 0; }

footer { margin-top: 46px; padding-top: 22px; border-top: 1px solid var(--line); font-size: 12.5px; color: var(--ink-3); }

/* ── Responsive ─────────────────────────── */
@media (max-width: 1000px) {
  .menu-btn { display: inline-flex; }
  .sidebar {
    position: fixed; top: var(--topbar-h); left: 0; z-index: 55;
    background: var(--bg-elev); box-shadow: var(--shadow-lg);
    transform: translateX(-102%); transition: transform .22s ease;
    width: min(300px, 86vw);
  }
  .sidebar.open { transform: none; }
  .content { padding-left: clamp(16px, 4vw, 28px); padding-right: clamp(16px, 4vw, 28px); }
  .scrim { position: fixed; inset: var(--topbar-h) 0 0; background: rgba(0,0,0,.42); z-index: 50; }
}
@media (max-width: 700px) {
  body { font-size: 15.5px; }
  .topbar { gap: 9px; padding: 0 12px; }
  .topbar .mark { font-size: 14px; }
  .progress-wrap .plabel, .progress-track, #viewmode, #cloud-chip .cloud-label { display: none; }
  .progress-wrap { white-space: nowrap; }
  #cloud-chip { max-width: none; padding: 0 10px; }
  .cloud-in .cloud-btns { margin-left: 0; }
  .v-stats { width: 100%; margin-left: 0; }
  .hero { padding-top: 34px; }
  .pager { grid-template-columns: 1fr; }
  .page-link.next { text-align: left; }
  .ch-head { gap: 10px; }
  .ch-title h2 { font-size: 22px; }
}

@media (max-width: 520px) {
  #ptext { display: none; }
}

@media print {
  .sidebar, .topbar, .giscus-wrap, .done-btn { display: none; }
  .chapter { break-inside: avoid; }
}

[hidden] { display: none !important; }