/* ============================================================
   Vibe Coding 道場 — 全站樣式 (warm-editorial, dark)
   引擎組產出。所有章頁引用，不准各自複製樣式。
   色值只出現在 :root。元件一律 var(--token)。
   ============================================================ */

:root {
  color-scheme: dark;
  --bg: #0e0d0a;
  --bg-alt: #18170f;
  --panel: #1c1b15;
  --panel-2: #211f17;
  --border: #2a261d;
  --border-strong: #3b3627;
  --text: #f0e9d8;
  --text-dim: #a39d8e;
  --text-muted: #6e6a5e;
  --accent: #d4a373;
  --accent-bright: #e6c197;
  --accent-soft: rgba(212, 163, 115, .12);
  --good: #4ade80;
  --warn: #fbbf24;
  --bad: #f87171;
  --info: #a78bfa;
  --r-container: 12px;
  --r-control: 8px;
  --focus: 0 0 0 2px rgba(212, 163, 115, .5);
  --maxw: 760px;
  --maxw-wide: 900px;
}

/* ── reset & base ─────────────────────────────────── */
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: 'Noto Sans TC', system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
.serif { font-family: 'Fraunces', Georgia, serif; }
.mono { font-family: 'JetBrains Mono', ui-monospace, monospace; }
a { color: var(--accent-bright); }
img { max-width: 100%; height: auto; }
::selection { background: var(--accent-soft); }

/* ── layout ───────────────────────────────────────── */
.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px 100px;
}
main.container { padding-top: 40px; }
section { margin: 56px 0; }
section:first-of-type { margin-top: 0; }

/* ── type ramp ────────────────────────────────────── */
.kicker {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 10.5px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--accent);
  display: inline-block;
  margin: 0 0 14px;
}
h1 {
  font-family: 'Fraunces', Georgia, serif;
  font-size: 40px;
  line-height: 1.22;
  font-weight: 700;
  letter-spacing: -.01em;
  margin: 0 0 20px;
}
h2 {
  font-family: 'Fraunces', Georgia, serif;
  font-size: 26px;
  line-height: 1.3;
  font-weight: 600;
  margin: 0 0 16px;
}
h3 {
  font-size: 19px;
  line-height: 1.4;
  font-weight: 600;
  margin: 28px 0 10px;
}
p { margin: 14px 0; }
.lead {
  font-size: 18px;
  color: var(--text-dim);
  line-height: 1.7;
  margin: 0 0 8px;
}
.lead b { color: var(--text); font-weight: 600; }
strong, b { font-weight: 600; color: var(--text); }
.dim { color: var(--text-dim); }
.muted { color: var(--text-muted); }
.num { font-variant-numeric: tabular-nums; }
code, .kbd {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: .9em;
  background: var(--accent-soft);
  color: var(--accent-bright);
  padding: 1px 6px;
  border-radius: 4px;
}
ul, ol { padding-left: 22px; }
li { margin: 6px 0; }

/* ── site header ──────────────────────────────────── */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: color-mix(in srgb, var(--bg) 92%, transparent);
  backdrop-filter: none;
  border-bottom: 1px solid var(--border);
}
.site-header-in {
  max-width: 1100px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}
.site-brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
  text-decoration: none;
  color: inherit;
}
.site-brand .mark {
  font-family: 'Fraunces', Georgia, serif;
  font-size: 19px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -.01em;
}
.site-brand .mark em { color: var(--accent); font-style: italic; font-weight: 500; }
.site-brand .sub {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 10px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--text-muted);
}
.site-header-right {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}
.site-header a.tolink {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 11px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--text-dim);
  text-decoration: none;
  transition: color .15s;
}
.site-header a.tolink:hover { color: var(--accent-bright); }

/* toc-progress 膠囊（header 內進度） */
.toc-progress {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--text-dim);
  border: 1px solid var(--border);
  background: var(--panel);
  padding: 5px 12px;
  border-radius: 999px;
}
.toc-progress .sep { color: var(--text-muted); }
.toc-progress .xp { color: var(--accent-bright); font-weight: 500; }
.toc-progress .xp .num { color: var(--accent-bright); }

/* ── hero ─────────────────────────────────────────── */
.hero { margin-bottom: 40px; }
.hero .promise {
  font-size: 18px;
  line-height: 1.7;
  color: var(--text-dim);
  margin: 0;
  max-width: 60ch;
}
.hero .promise b { color: var(--text); }
.belt-line { display: flex; align-items: center; gap: 10px; margin: 0 0 14px; flex-wrap: wrap; }

/* ── belt-pill 段位膠囊 ───────────────────────────── */
.belt-pill {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 10.5px;
  letter-spacing: .12em;
  text-transform: uppercase;
  padding: 4px 11px 4px 9px;
  border-radius: 999px;
  border: 1px solid var(--border-strong);
  color: var(--text-dim);
  background: var(--panel);
}
.belt-pill::before {
  content: "";
  width: 9px; height: 9px;
  border-radius: 2px;
  background: var(--accent);
  border: 1px solid rgba(0,0,0,.25);
}
/* 五段位：用 accent 濃淡 + 邊框區分，不搞彩虹 */
.belt-pill.white  { color: var(--text); }
.belt-pill.white::before  { background: #e9e3d4; }
.belt-pill.yellow::before { background: var(--accent-bright); }
.belt-pill.green  { border-color: color-mix(in srgb, var(--accent) 55%, var(--border)); }
.belt-pill.green::before  { background: var(--accent); }
.belt-pill.blue   { border-color: color-mix(in srgb, var(--accent) 70%, var(--border)); }
.belt-pill.blue::before   { background: color-mix(in srgb, var(--accent) 75%, var(--text-muted)); }
.belt-pill.black  { color: var(--accent-bright); border-color: var(--accent); }
.belt-pill.black::before  { background: #0e0d0a; border: 1px solid var(--accent); }

/* ── card / callout ───────────────────────────────── */
.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--r-container);
  padding: 20px 22px;
}
.card .t { font-size: 15px; font-weight: 600; margin: 0 0 8px; color: var(--text); }
.card p, .card li { color: var(--text-dim); }
.card p:first-child { margin-top: 0; }
.card p:last-child { margin-bottom: 0; }

.callout {
  background: var(--panel);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: var(--r-control);
  padding: 16px 18px 16px 20px;
  margin: 22px 0;
}
.callout .t {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 10.5px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 8px;
}
.callout p { margin: 0; color: var(--text-dim); font-size: 15.5px; }
.callout p + p { margin-top: 10px; }
.callout.warn { border-left-color: var(--warn); }
.callout.warn .t { color: var(--warn); }
.callout.info { border-left-color: var(--info); }
.callout.info .t { color: var(--info); }

.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.grid3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }

/* ── diff-note 差異化筆記 ─────────────────────────── */
.diff-note {
  background: linear-gradient(180deg, var(--panel-2), var(--panel));
  border: 1px solid var(--border-strong);
  border-radius: var(--r-container);
  padding: 22px 24px;
}
.diff-note::before {
  content: "差異化筆記 — 你 vs 純 vibe coder";
  display: block;
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 10.5px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 14px;
}
.diff-note p { margin: 10px 0; color: var(--text-dim); font-size: 15.5px; }
.diff-note p:last-child { margin-bottom: 0; }
.diff-note b { color: var(--text); }

/* ── code-block ───────────────────────────────────── */
.code-block {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-left: 2px solid var(--accent);
  border-radius: var(--r-control);
  margin: 20px 0;
  overflow: hidden;
}
.code-block .cap {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 10.5px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--text-muted);
  padding: 8px 16px;
  border-bottom: 1px solid var(--border);
  background: var(--panel);
}
.code-block pre {
  margin: 0;
  padding: 16px;
  overflow-x: auto;
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--text);
  white-space: pre;
  tab-size: 2;
}
.code-block pre .cm { color: var(--text-muted); }   /* 註解 */
.code-block pre .st { color: var(--good); }          /* 字串 */
.code-block pre .kw { color: var(--accent-bright); } /* 關鍵字 */
.code-block pre .nm { color: var(--info); }          /* 數字 */

/* ── interactive-stage 招牌互動外殼 ───────────────── */
.interactive-stage {
  background: var(--panel-2);
  border: 1px solid var(--border-strong);
  border-radius: var(--r-container);
  padding: 22px 24px 24px;
  transition: border-color .2s;
}
.interactive-stage .stage-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 4px;
}
.interactive-stage .stage-kicker {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 10.5px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--accent);
}
.interactive-stage h2 { margin: 6px 0 8px; }
.interactive-stage .stage-desc {
  font-size: 15px;
  color: var(--text-dim);
  margin: 0 0 18px;
}
.interactive-stage .stage-body { margin-top: 4px; }
.interactive-stage.done { border-color: var(--accent); }
.interactive-stage .stage-done-banner {
  display: none;
  align-items: center;
  gap: 10px;
  margin-top: 18px;
  padding: 12px 16px;
  border-radius: var(--r-control);
  background: var(--accent-soft);
  border: 1px solid var(--accent);
  color: var(--accent-bright);
  font-size: 14px;
}
.interactive-stage.done .stage-done-banner { display: flex; }
.stage-done-banner .chk {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-weight: 500;
}

/* ── buttons ──────────────────────────────────────── */
.btn {
  font-family: 'Noto Sans TC', system-ui, sans-serif;
  font-size: 14px;
  font-weight: 500;
  line-height: 1;
  padding: 9px 16px;
  border-radius: var(--r-control);
  border: 1px solid var(--border-strong);
  background: var(--panel);
  color: var(--text);
  cursor: pointer;
  transition: border-color .15s, background .15s, transform .1s, color .15s;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.btn:hover { border-color: var(--accent); color: var(--accent-bright); }
.btn:active { transform: translateY(1px); }
.btn:focus-visible { outline: none; box-shadow: var(--focus); }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn:disabled:hover { border-color: var(--border-strong); color: var(--text); }
.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #17130c;
  font-weight: 600;
}
.btn-primary:hover { background: var(--accent-bright); border-color: var(--accent-bright); color: #17130c; }
.btn-ghost {
  background: transparent;
  border-color: transparent;
  color: var(--text-dim);
}
.btn-ghost:hover { color: var(--accent-bright); border-color: var(--border); }
.btn-sm { font-size: 12.5px; padding: 6px 12px; }
.btn-row { display: flex; flex-wrap: wrap; gap: 8px; }

/* ── playground ───────────────────────────────────── */
.pg {
  border: 1px solid var(--border);
  border-radius: var(--r-container);
  background: var(--panel);
  overflow: hidden;
}
.pg-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 8px 12px;
  background: var(--bg-alt);
  border-bottom: 1px solid var(--border);
}
.pg-bar .label {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 10.5px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--text-muted);
}
.pg-editor {
  width: 100%;
  border: 0;
  resize: vertical;
  background: var(--bg-alt);
  color: var(--text);
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 13.5px;
  line-height: 1.7;
  padding: 14px 16px;
  tab-size: 2;
  display: block;
}
.pg-editor:focus { outline: none; box-shadow: inset var(--focus); }
.pg-console {
  border-top: 1px solid var(--border);
  background: #0b0a07;
  min-height: 48px;
  max-height: 260px;
  overflow-y: auto;
  padding: 10px 16px;
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 13px;
  line-height: 1.6;
}
.pg-console .row { white-space: pre-wrap; word-break: break-word; margin: 2px 0; color: var(--text); }
.pg-console .row.err { color: var(--bad); }
.pg-console .row.warn { color: var(--warn); }
.pg-console .row.muted { color: var(--text-muted); }
.pg-console .empty {
  color: var(--text-muted);
  font-style: normal;
}
.pg-tasks { margin-top: 14px; display: grid; gap: 8px; }
.pg-task {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: var(--r-control);
  background: var(--panel);
  font-size: 14px;
  color: var(--text-dim);
  transition: border-color .15s, color .15s;
}
.pg-task .box {
  flex: none;
  width: 18px; height: 18px;
  border-radius: 5px;
  border: 1.5px solid var(--border-strong);
  display: flex; align-items: center; justify-content: center;
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 12px;
  color: transparent;
  margin-top: 1px;
  transition: all .15s;
}
.pg-task.done { border-color: color-mix(in srgb, var(--accent) 55%, var(--border)); color: var(--text); }
.pg-task.done .box { background: var(--accent); border-color: var(--accent); color: #17130c; }

/* ── quiz ─────────────────────────────────────────── */
.quiz-block { display: grid; gap: 18px; }
.quiz-q {
  border: 1px solid var(--border);
  border-radius: var(--r-container);
  background: var(--panel);
  padding: 18px 20px;
}
.quiz-q .qhead {
  display: flex;
  gap: 10px;
  align-items: baseline;
  margin-bottom: 14px;
}
.quiz-q .qnum {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--accent);
  flex: none;
}
.quiz-q .qtext { font-size: 16px; font-weight: 600; color: var(--text); line-height: 1.6; }
.quiz-opts { display: grid; gap: 8px; }
.quiz-opt {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  width: 100%;
  text-align: left;
  padding: 11px 14px;
  border: 1px solid var(--border);
  border-radius: var(--r-control);
  background: var(--bg-alt);
  color: var(--text-dim);
  font-size: 14.5px;
  line-height: 1.55;
  cursor: pointer;
  font-family: inherit;
  transition: border-color .15s, background .15s, color .15s;
}
.quiz-opt:hover:not(:disabled) { border-color: var(--accent); color: var(--text); }
.quiz-opt:focus-visible { outline: none; box-shadow: var(--focus); }
.quiz-opt .mk {
  flex: none;
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 12px;
  color: var(--text-muted);
  width: 18px;
}
.quiz-opt:disabled { cursor: default; }
.quiz-opt.correct {
  border-color: var(--good);
  background: color-mix(in srgb, var(--good) 12%, transparent);
  color: var(--text);
}
.quiz-opt.correct .mk { color: var(--good); }
.quiz-opt.wrong {
  border-color: var(--bad);
  background: color-mix(in srgb, var(--bad) 12%, transparent);
  color: var(--text);
}
.quiz-opt.wrong .mk { color: var(--bad); }
.quiz-explain {
  margin-top: 14px;
  padding: 12px 16px;
  border-radius: var(--r-control);
  background: var(--bg-alt);
  border-left: 3px solid var(--accent);
  font-size: 14px;
  color: var(--text-dim);
  line-height: 1.7;
}
.quiz-explain b { color: var(--text); }
.quiz-explain .verdict { font-weight: 600; }
.quiz-explain .verdict.ok { color: var(--good); }
.quiz-explain .verdict.no { color: var(--bad); }
.quiz-score {
  margin-top: 4px;
  padding: 16px 20px;
  border: 1px solid var(--accent);
  border-radius: var(--r-container);
  background: var(--accent-soft);
  text-align: center;
}
.quiz-score .big {
  font-family: 'Fraunces', Georgia, serif;
  font-size: 30px;
  font-weight: 700;
  color: var(--accent-bright);
  font-variant-numeric: tabular-nums;
}
.quiz-score p { margin: 4px 0 0; color: var(--text-dim); font-size: 14px; }

/* ── chapter-nav ──────────────────────────────────── */
.chapter-nav {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 14px;
  align-items: stretch;
  margin: 64px 0 0;
  border-top: 1px solid var(--border);
  padding-top: 28px;
}
.chapter-nav a, .chapter-nav span.nav-empty {
  border: 1px solid var(--border);
  border-radius: var(--r-container);
  padding: 14px 18px;
  text-decoration: none;
  color: var(--text);
  transition: border-color .15s, transform .1s;
  display: flex;
  flex-direction: column;
  gap: 3px;
  justify-content: center;
}
.chapter-nav a:hover { border-color: var(--accent); transform: translateY(-2px); }
.chapter-nav .dir {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 10px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--text-muted);
}
.chapter-nav .ttl { font-size: 14.5px; font-weight: 600; }
.chapter-nav a.next { text-align: right; align-items: flex-end; }
.chapter-nav a.toc { text-align: center; align-items: center; justify-content: center; color: var(--accent-bright); }
.chapter-nav span.nav-empty { border-style: dashed; opacity: .4; }

/* ── footer ───────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--border);
  margin-top: 40px;
}
.site-footer-in {
  max-width: 1100px;
  margin: 0 auto;
  padding: 22px 24px;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 10px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--text-muted);
}

/* ── index-only 元件 ──────────────────────────────── */
.home-hero {
  text-align: center;
  padding: 64px 0 24px;
  max-width: 640px;
  margin: 0 auto;
}
.home-hero h1 { font-size: 44px; margin: 16px 0 18px; }
.home-hero h1 em { color: var(--accent); font-style: italic; font-weight: 500; }
.home-hero .tagline {
  font-size: 18px;
  color: var(--text-dim);
  margin: 0 auto 12px;
}
.home-hero .claim {
  font-size: 15.5px;
  color: var(--text-muted);
  max-width: 46ch;
  margin: 0 auto 26px;
  line-height: 1.7;
}
.what-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.what-card {
  border: 1px solid var(--border);
  border-radius: var(--r-container);
  background: var(--panel);
  padding: 22px 20px;
}
.what-card .n {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--accent);
}
.what-card .t { font-family: 'Fraunces', Georgia, serif; font-size: 20px; font-weight: 600; margin: 8px 0 8px; }
.what-card p { margin: 0; font-size: 14.5px; color: var(--text-dim); }

.belt-section { margin: 48px 0; }
.belt-section-head {
  display: flex;
  align-items: center;
  gap: 14px;
  margin: 0 0 20px;
  flex-wrap: wrap;
}
.belt-section-head .theme {
  font-family: 'Fraunces', Georgia, serif;
  font-size: 22px;
  font-weight: 600;
  color: var(--text);
}
.belt-section-head .line { height: 1px; flex: 1; min-width: 20px; background: var(--border); }

.chap-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
.chap-card {
  display: block;
  border: 1px solid var(--border);
  border-radius: var(--r-container);
  background: var(--panel);
  padding: 16px 18px;
  text-decoration: none;
  color: inherit;
  transition: border-color .15s, transform .1s;
}
.chap-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.chap-card .cnum {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 10.5px;
  letter-spacing: .1em;
  color: var(--text-muted);
}
.chap-card .ctitle { font-size: 15.5px; font-weight: 600; color: var(--text); margin: 4px 0 5px; line-height: 1.4; }
.chap-card .cinter { font-size: 12.5px; color: var(--text-muted); font-family: 'JetBrains Mono', ui-monospace, monospace; letter-spacing: .02em; }
.chap-dots { display: flex; gap: 6px; margin-top: 12px; }
.chap-dots .dot {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 9.5px;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--text-muted);
}
.chap-dots .dot::before {
  content: "";
  width: 8px; height: 8px;
  border-radius: 50%;
  background: transparent;
  border: 1.5px solid var(--border-strong);
}
.chap-dots .dot.on { color: var(--accent-bright); }
.chap-dots .dot.on::before { background: var(--accent); border-color: var(--accent); }

.xp-panel {
  border: 1px solid var(--border);
  border-radius: var(--r-container);
  background: linear-gradient(180deg, var(--panel-2), var(--panel));
  padding: 24px 26px;
}
.xp-panel .grid2 { align-items: start; }
.xp-stat { display: flex; align-items: baseline; gap: 8px; }
.xp-stat .v {
  font-family: 'Fraunces', Georgia, serif;
  font-size: 34px;
  font-weight: 700;
  color: var(--accent-bright);
  font-variant-numeric: tabular-nums;
}
.xp-stat .k { font-size: 13px; color: var(--text-muted); }
.belt-ladder { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 4px; }

/* ── motion ───────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
}

/* ── responsive ───────────────────────────────────── */
@media (max-width: 680px) {
  body { font-size: 15.5px; }
  .container { padding: 0 18px 80px; }
  h1 { font-size: 32px; }
  .home-hero h1 { font-size: 34px; }
  h2 { font-size: 23px; }
  .grid2, .grid3, .what-cards, .chap-grid { grid-template-columns: 1fr; }
  .interactive-stage, .card, .diff-note, .xp-panel { padding-left: 16px; padding-right: 16px; }
  .chapter-nav { grid-template-columns: 1fr; }
  .chapter-nav a.next { text-align: left; align-items: flex-start; }
  .site-header-in { padding: 12px 18px; }
  .home-hero { padding-top: 40px; }
}

/* ── print ────────────────────────────────────────── */
@media print {
  :root {
    --bg: #fff; --bg-alt: #f5f2ec; --panel: #faf8f4; --panel-2: #f3efe7;
    --border: #ddd6c8; --border-strong: #c9c1ac;
    --text: #1c1a14; --text-dim: #545044; --text-muted: #8a8475;
    --accent: #a87544; --accent-bright: #8a5e34;
  }
  .site-header, .chapter-nav, .interactive-stage, .pg { break-inside: avoid; }
}