/* AlterU Training Slide Deck — shared styles
   Brand tokens borrowed from /Users/yin/code/alteru-landing/_shared.css
   Each .html is a single full-viewport slide. Layouts:
     .slide.cover         hero-style w/ big italic title
     .slide.split         left text / right image (or inverted)
     .slide.matrix-2x2    2x2 grid of cards
     .slide.matrix-3x3    3 cols
     .slide.wide          single full-bleed image with overlay text
     .slide.compare       2 column compare list (vs)
     .slide.case-study    portrait left + 4 key points right
     .slide.callout       single big quote
     .slide.checklist     numbered checklist
*/

:root {
  --brand-pink: #F5B1C7;
  --brand-pink-strong: #FF94B7;
  --brand-pink-dim: rgba(245, 177, 199, 0.12);
  --ink: #000000;
  --surface-1: #0a0a0c;
  --surface-2: #0d0d10;
  --surface-3: #16161a;
  --border: #2a2a2e;
  --text-1: #FFFFFF;
  --text-2: #D9D9D9;
  --text-3: #9B9BA1;
  --text-on-brand: #1F1F1F;
  --danger: #ff5577;
  --ok: #6ee7a8;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
html, body { margin: 0; padding: 0; height: 100%; }
body {
  background: var(--surface-1);
  color: var(--text-1);
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  -webkit-font-smoothing: antialiased;
  overflow: hidden;
}

/* ─── Slide container — exactly viewport ───────────────────── */
.slide {
  width: 100vw;
  min-height: 100vh;
  padding: 64px clamp(40px, 6vw, 96px) 96px;
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
}
@media print {
  body { overflow: visible; background: white; color: black; }
  .slide { page-break-after: always; min-height: 100vh; }
  .slide-nav { display: none !important; }
  .slide-progress { display: none !important; }
}

/* ─── Typography ───────────────────────────────────────────── */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: 'Montserrat', sans-serif;
  font-weight: 700;
  font-size: 12px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--brand-pink);
  margin-bottom: 24px;
}
.eyebrow .dot {
  width: 6px; height: 6px; border-radius: 999px;
  background: var(--brand-pink);
  box-shadow: 0 0 12px var(--brand-pink);
}
h1.title {
  font-family: 'Montserrat', sans-serif;
  font-weight: 900;
  font-size: clamp(40px, 5.5vw, 84px);
  line-height: 0.98;
  letter-spacing: -0.035em;
  margin: 0 0 24px;
  color: var(--text-1);
  max-width: 24ch;
}
h1.title em {
  font-style: italic;
  color: var(--brand-pink);
}
h2.title {
  font-family: 'Montserrat', sans-serif;
  font-weight: 800;
  font-size: clamp(32px, 4vw, 56px);
  line-height: 1.04;
  letter-spacing: -0.025em;
  margin: 0 0 20px;
  color: var(--text-1);
  max-width: 22ch;
}
h2.title em { font-style: italic; color: var(--brand-pink); }
.sub {
  font-size: clamp(16px, 1.4vw, 20px);
  line-height: 1.55;
  color: var(--text-2);
  max-width: 50ch;
  margin: 0 0 32px;
}
.sub strong { color: var(--text-1); font-weight: 600; }
.micro {
  font-family: 'Montserrat', sans-serif;
  font-weight: 600;
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-3);
}
.pink { color: var(--brand-pink); }
.danger { color: var(--danger); }
.ok { color: var(--ok); }
.dim { color: var(--text-3); }

/* ─── Layout: cover ─────────────────────────────────────────── */
.slide.cover {
  justify-content: center;
  align-items: flex-start;
  background:
    radial-gradient(900px 600px at 75% 30%, rgba(245,177,199,0.10), transparent 70%),
    var(--surface-1);
}
.slide.cover .title { font-size: clamp(48px, 8vw, 120px); max-width: 18ch; }
.slide.cover .sub { font-size: clamp(18px, 1.6vw, 24px); max-width: 56ch; }

/* ─── Layout: split (left text / right visual) ─────────────── */
.slide.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}
.slide.split.flip { grid-template-columns: 1fr 1fr; }
.slide.split.flip .col-text { order: 2; }
.slide.split.flip .col-visual { order: 1; }
.slide.split .col-text {
  display: flex; flex-direction: column; justify-content: center;
}
.slide.split .col-visual {
  display: flex; align-items: center; justify-content: center;
  position: relative;
  height: 100%;
}
.slide.split .col-visual img,
.slide.split .col-visual video {
  width: 100%;
  height: auto;
  max-height: 80vh;
  object-fit: contain;
  border-radius: 22px;
  box-shadow: 0 30px 90px rgba(0,0,0,0.6), 0 0 0 1px rgba(255,255,255,0.04);
}
@media (max-width: 900px) {
  .slide.split { grid-template-columns: 1fr; gap: 32px; }
}

/* ─── Layout: matrix grids ─────────────────────────────────── */
.slide.matrix-2x2 .grid,
.slide.matrix-3x3 .grid,
.slide.matrix-4 .grid {
  flex: 1;
  display: grid;
  gap: 20px;
  margin-top: 32px;
  align-content: start;
}
.slide.matrix-2x2 .grid { grid-template-columns: 1fr 1fr; }
.slide.matrix-3x3 .grid { grid-template-columns: 1fr 1fr 1fr; }
.slide.matrix-4   .grid { grid-template-columns: repeat(4, 1fr); }
.cell {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 28px 26px;
  position: relative;
}
a.cell {
  text-decoration: none;
  color: inherit;
  display: block;
  transition: transform 200ms ease, border-color 200ms ease, box-shadow 200ms ease;
  cursor: pointer;
}
a.cell:hover {
  transform: translateY(-3px);
  border-color: var(--brand-pink);
  box-shadow: 0 22px 50px rgba(245, 177, 199, 0.10);
}
a.cell:hover .cell-num { color: var(--brand-pink-strong); opacity: 0.32; }
a.cell::after {
  content: '→';
  position: absolute;
  bottom: 18px; right: 22px;
  font-family: 'Montserrat', sans-serif;
  font-weight: 700;
  font-size: 16px;
  color: var(--text-3);
  opacity: 0;
  transform: translateX(-6px);
  transition: opacity 200ms ease, transform 200ms ease, color 200ms ease;
}
a.cell:hover::after {
  opacity: 1;
  transform: translateX(0);
  color: var(--brand-pink);
}
.cell .cell-num {
  position: absolute; top: 16px; right: 22px;
  font-family: 'Montserrat', sans-serif;
  font-weight: 900;
  font-size: 64px; line-height: 1;
  color: var(--brand-pink); opacity: 0.16;
  pointer-events: none;
}
.cell h3 {
  font-family: 'Montserrat', sans-serif;
  font-weight: 700;
  font-size: 22px;
  margin: 0 0 12px;
  color: var(--text-1);
}
.cell p {
  font-size: 15px;
  line-height: 1.55;
  color: var(--text-3);
  margin: 0;
}
.cell img.cell-poster {
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  border-radius: 12px;
  margin-bottom: 14px;
}
.cell .tag {
  display: inline-block;
  font-family: 'Montserrat', sans-serif;
  font-weight: 700; font-size: 10px;
  letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--brand-pink);
  background: var(--brand-pink-dim);
  padding: 4px 10px; border-radius: 999px;
  margin-bottom: 12px;
}

/* ─── Bullet lists (used in many layouts) ──────────────────── */
ul.bullets {
  list-style: none;
  padding: 0; margin: 0;
  display: flex; flex-direction: column;
  gap: 14px;
}
ul.bullets li {
  position: relative;
  padding-left: 28px;
  font-size: 16px; line-height: 1.55;
  color: var(--text-2);
}
ul.bullets li::before {
  content: '';
  position: absolute; left: 0; top: 10px;
  width: 12px; height: 2px;
  background: var(--brand-pink);
}
ul.bullets strong { color: var(--text-1); font-weight: 600; }

/* ─── Compare table (vs / 反例 vs 正例) ───────────────────── */
.compare-row {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 24px;
  align-items: start;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 18px 20px;
  margin-bottom: 14px;
}
.compare-row .vs {
  align-self: center;
  font-family: 'Montserrat', sans-serif;
  font-weight: 900;
  font-size: 14px;
  color: var(--text-3);
  letter-spacing: 0.18em;
}
.compare-row .bad { color: var(--text-3); }
.compare-row .bad b { color: var(--danger); }
.compare-row .good b { color: var(--ok); }
.compare-row code {
  display: block;
  margin-top: 6px;
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 13px;
  background: rgba(255,255,255,0.04);
  padding: 8px 10px;
  border-radius: 6px;
  color: var(--text-2);
}

/* ─── Checklist ─────────────────────────────────────────────── */
.check {
  display: flex; align-items: flex-start; gap: 14px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px 20px;
  margin-bottom: 12px;
}
.check .box {
  flex-shrink: 0;
  width: 26px; height: 26px;
  border: 2px solid var(--brand-pink);
  border-radius: 6px;
  margin-top: 2px;
}
.check b { color: var(--text-1); }
.check p { margin: 6px 0 0; color: var(--text-3); font-size: 14px; }

/* ─── Quote / callout ──────────────────────────────────────── */
.slide.callout { justify-content: center; align-items: center; text-align: center; }
.slide.callout .big-quote {
  font-family: 'Montserrat', sans-serif;
  font-weight: 800;
  font-size: clamp(36px, 5vw, 72px);
  line-height: 1.05;
  letter-spacing: -0.025em;
  max-width: 22ch;
  margin: 0 auto 24px;
}
.slide.callout .big-quote em { font-style: italic; color: var(--brand-pink); }
.slide.callout .quote-attr {
  font-family: 'Montserrat', sans-serif;
  font-weight: 600;
  font-size: 13px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-3);
}

/* ─── Poster wall (case-study left rail) ───────────────────── */
.poster-wall {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin-top: 24px;
}
.poster-wall .ptile {
  aspect-ratio: 1 / 1;
  border-radius: 12px;
  overflow: hidden;
  background: var(--surface-2);
  border: 1px solid var(--border);
  position: relative;
}
.poster-wall .ptile img {
  width: 100%; height: 100%; object-fit: cover;
  display: block;
}
.poster-wall .ptile .pname {
  position: absolute; left: 10px; bottom: 10px;
  font-family: 'Montserrat', sans-serif;
  font-weight: 700; font-size: 11px;
  letter-spacing: 0.1em; text-transform: uppercase;
  text-shadow: 0 2px 6px rgba(0,0,0,0.8);
  z-index: 2;
}
.poster-wall .ptile::after {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(180deg, transparent 50%, rgba(0,0,0,0.6) 100%);
  pointer-events: none;
}

/* ─── Tags / pills ─────────────────────────────────────────── */
.pill {
  display: inline-block;
  font-family: 'Montserrat', sans-serif;
  font-weight: 700; font-size: 11px;
  letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--brand-pink);
  background: var(--brand-pink-dim);
  border: 1px solid rgba(245,177,199,0.32);
  padding: 6px 12px; border-radius: 999px;
  margin-right: 8px;
}
.pill.danger {
  color: var(--danger);
  background: rgba(255,85,119,0.10);
  border-color: rgba(255,85,119,0.32);
}
.pill.ok {
  color: var(--ok);
  background: rgba(110,231,168,0.10);
  border-color: rgba(110,231,168,0.32);
}

/* ─── Top brand strip ─────────────────────────────────────── */
.brand-strip {
  position: fixed;
  top: 18px; left: 24px;
  display: flex; align-items: center; gap: 10px;
  z-index: 30;
  pointer-events: none;
}
.brand-strip a.brand-home {
  pointer-events: auto; cursor: pointer;
  display: flex; align-items: center; gap: 10px;
  text-decoration: none; color: inherit;
  transition: opacity 0.15s ease;
}
.brand-strip a.brand-home:hover { opacity: 0.7; }
.brand-strip img { width: 26px; height: 26px; }
.brand-strip .brand-name {
  font-family: 'Montserrat', sans-serif;
  font-weight: 800; font-size: 13px;
  letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--text-1);
}
.brand-strip .brand-sep {
  width: 22px; height: 1px; background: var(--text-3); opacity: 0.5;
}
.brand-strip .brand-context {
  font-family: 'Montserrat', sans-serif;
  font-weight: 600; font-size: 11px;
  letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--text-3);
}

/* ─── Nav: prev/next + progress ───────────────────────────── */
.slide-nav {
  position: fixed;
  bottom: 24px; right: 24px;
  display: flex; gap: 10px;
  z-index: 30;
}
.slide-nav a {
  display: inline-flex; align-items: center; gap: 6px;
  text-decoration: none;
  font-family: 'Montserrat', sans-serif;
  font-weight: 700; font-size: 12px;
  letter-spacing: 0.14em; text-transform: uppercase;
  padding: 10px 16px;
  border-radius: 999px;
  background: rgba(20,20,24,0.86);
  border: 1px solid var(--border);
  color: var(--text-2);
  backdrop-filter: blur(8px);
  transition: background 180ms, color 180ms, border-color 180ms;
}
.slide-nav a:hover { color: var(--text-1); background: var(--surface-3); }
.slide-nav a.next { background: var(--brand-pink); color: var(--text-on-brand); border-color: var(--brand-pink); }
.slide-nav a.next:hover { background: var(--brand-pink-strong); }
.slide-nav a.disabled { opacity: 0.3; pointer-events: none; }

.slide-progress {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: rgba(255,255,255,0.05);
  z-index: 40;
}
.slide-progress .fill {
  height: 100%;
  background: var(--brand-pink);
  box-shadow: 0 0 12px var(--brand-pink);
}
.slide-page-tag {
  position: fixed;
  bottom: 30px; left: 24px;
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--text-3);
  z-index: 30;
  pointer-events: none;
}

/* ─── Speaker notes (hidden by default, toggle with key 's') ── */
.speaker-notes {
  position: fixed;
  left: 24px; right: 24px; bottom: 80px;
  background: rgba(20,20,24,0.96);
  border: 1px solid var(--brand-pink);
  border-radius: 18px;
  padding: 22px 26px;
  max-height: 40vh;
  overflow-y: auto;
  z-index: 35;
  font-size: 14px; line-height: 1.6;
  color: var(--text-2);
  display: none;
  backdrop-filter: blur(12px);
}
.speaker-notes.visible { display: block; }
.speaker-notes h4 {
  font-family: 'Montserrat', sans-serif;
  margin: 0 0 10px;
  font-size: 11px; letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--brand-pink);
}
.speaker-notes p { margin: 0 0 8px; }
.speaker-notes p:last-child { margin-bottom: 0; }

/* ─── Top-right action bar (menu + language) ─────────────── */
.action-bar {
  position: fixed;
  top: 18px; right: 24px;
  display: flex; gap: 8px;
  z-index: 40;
}
.action-bar button,
.action-bar a {
  display: inline-flex; align-items: center; gap: 6px;
  font-family: 'Montserrat', sans-serif;
  font-weight: 700; font-size: 11px;
  letter-spacing: 0.14em; text-transform: uppercase;
  padding: 9px 14px;
  border-radius: 999px;
  background: rgba(20,20,24,0.86);
  border: 1px solid var(--border);
  color: var(--text-2);
  backdrop-filter: blur(8px);
  cursor: pointer;
  text-decoration: none;
  transition: background 180ms, color 180ms, border-color 180ms;
}
.action-bar button:hover,
.action-bar a:hover {
  color: var(--text-1); background: var(--surface-3); border-color: var(--text-3);
}
.action-bar .lang-btn .lang-active {
  color: var(--brand-pink);
}

/* ─── Menu drawer ──────────────────────────────────────────── */
.menu-backdrop {
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.72);
  z-index: 90;
  opacity: 0; pointer-events: none;
  transition: opacity 220ms;
  backdrop-filter: blur(4px);
}
.menu-backdrop.open { opacity: 1; pointer-events: auto; }

.menu-drawer {
  position: fixed;
  top: 0; right: 0; bottom: 0;
  width: min(420px, 85vw);
  background: var(--surface-2);
  border-left: 1px solid var(--border);
  z-index: 95;
  transform: translateX(100%);
  transition: transform 280ms cubic-bezier(0.2, 0.7, 0.2, 1);
  overflow-y: auto;
  padding: 24px 24px 32px;
}
.menu-drawer.open { transform: translateX(0); }

.menu-drawer .menu-head {
  display: flex; justify-content: space-between; align-items: baseline;
  margin-bottom: 24px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border);
}
.menu-drawer .menu-head h3 {
  font-family: 'Montserrat', sans-serif;
  font-weight: 800; font-size: 16px;
  margin: 0;
  letter-spacing: 0.06em;
}
.menu-drawer .menu-head .menu-close {
  background: transparent; border: 0;
  font-family: 'Montserrat', sans-serif;
  font-weight: 700; font-size: 11px;
  letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--text-3);
  cursor: pointer;
  padding: 4px 10px;
}
.menu-drawer .menu-head .menu-close:hover { color: var(--brand-pink); }

.menu-drawer .menu-section { margin-bottom: 18px; }
.menu-drawer .menu-section-title {
  font-family: 'Montserrat', sans-serif;
  font-weight: 700; font-size: 10px;
  letter-spacing: 0.22em; text-transform: uppercase;
  color: var(--brand-pink);
  margin-bottom: 8px;
}
.menu-drawer .menu-item {
  display: flex; align-items: baseline; gap: 12px;
  padding: 9px 12px;
  border-radius: 8px;
  text-decoration: none;
  color: var(--text-2);
  font-size: 14px;
  line-height: 1.4;
  transition: background 140ms, color 140ms;
}
.menu-drawer .menu-item:hover { background: var(--surface-3); color: var(--text-1); }
.menu-drawer .menu-item.current {
  background: var(--brand-pink-dim);
  color: var(--brand-pink);
}
.menu-drawer .menu-item .menu-num {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 11px; color: var(--text-3); flex-shrink: 0;
  width: 24px;
}
.menu-drawer .menu-item.current .menu-num { color: var(--brand-pink); }

.menu-drawer .menu-foot {
  margin-top: 24px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  font-size: 11px; color: var(--text-3); line-height: 1.6;
}
.menu-drawer .menu-foot kbd {
  display: inline-block;
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 10px;
  background: var(--surface-3);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 6px;
  margin: 0 2px;
  color: var(--text-2);
}

/* ─── Language switching (data-lang attr on html) ─────────── */
/* `display: contents` makes the data-only wrapper transparent to layout,
   so children (col-text / col-visual / cells / etc.) become direct
   grid/flex items of the .slide container instead of stacking inside an
   accidental block parent. Then display: none wins when the lang doesn't
   match. Chrome/Edge/Safari/Firefox all support display:contents. */
[data-only="zh"], [data-only="en"] { display: contents; }
html[data-lang="zh"] [data-only="en"] { display: none !important; }
html[data-lang="en"] [data-only="zh"] { display: none !important; }

/* ─── Outline / contents preview page ─────────────────────── */
.outline-page {
  min-height: 100vh;
  padding: 96px clamp(24px, 5vw, 64px) 64px;
  background: var(--surface-1);
}
.outline-head {
  max-width: 1200px;
  margin: 0 auto 48px;
}
.outline-head h1 {
  font-family: 'Montserrat', sans-serif;
  font-weight: 900;
  font-size: clamp(40px, 5vw, 64px);
  line-height: 1.0;
  letter-spacing: -0.03em;
  margin: 0 0 12px;
}
.outline-head h1 em {
  font-style: italic; color: var(--brand-pink);
}
.outline-head p {
  color: var(--text-3);
  font-size: 16px;
  margin: 0;
  max-width: 60ch;
}
.outline-part {
  max-width: 1200px;
  margin: 0 auto 48px;
}
.outline-part-head {
  display: flex; align-items: baseline; gap: 12px;
  margin-bottom: 20px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
}
.outline-part-head .num {
  font-family: 'Montserrat', sans-serif;
  font-weight: 900; font-size: 12px;
  letter-spacing: 0.22em; text-transform: uppercase;
  color: var(--brand-pink);
}
.outline-part-head h2 {
  font-family: 'Montserrat', sans-serif;
  font-weight: 800; font-size: 22px;
  margin: 0; color: var(--text-1);
  letter-spacing: -0.01em;
}
.outline-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 18px;
}
.outline-thumb {
  position: relative;
  display: block;
  text-decoration: none;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
  transition: transform 220ms, border-color 220ms, box-shadow 220ms;
}
.outline-thumb:hover {
  transform: translateY(-3px);
  border-color: var(--brand-pink);
  box-shadow: 0 18px 40px rgba(245,177,199,0.10);
}
.outline-thumb .thumb-frame {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background: var(--ink);
}
.outline-thumb .thumb-frame iframe {
  position: absolute; top: 0; left: 0;
  width: 1440px; height: 810px;
  border: 0;
  transform-origin: top left;
  pointer-events: none;
}
.outline-thumb .thumb-meta {
  display: flex; align-items: baseline; gap: 10px;
  padding: 12px 14px;
  font-family: 'Montserrat', sans-serif;
  font-weight: 600;
  font-size: 13px;
  color: var(--text-2);
  border-top: 1px solid var(--border);
}
.outline-thumb .thumb-num {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 11px;
  color: var(--text-3);
  letter-spacing: 0.05em;
}
.outline-thumb .thumb-title {
  flex: 1;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}

/* ─── Reduced motion ──────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}