/* ================================
   Cinema Mode — Keynote-style deck
   ================================ */

:root {
  --bg: #000;
  --ink: #f5f5f7;
  --ink-dim: rgba(245, 245, 247, 0.58);
  --ink-faint: rgba(245, 245, 247, 0.32);
  --line: rgba(245, 245, 247, 0.10);
  --line-strong: rgba(245, 245, 247, 0.22);
  --cyan: oklch(0.82 0.13 200);
  --cyan-deep: oklch(0.66 0.16 220);
  --coral: oklch(0.78 0.15 30);
  --amber: oklch(0.86 0.14 85);
  --lime: oklch(0.86 0.18 145);
  --violet: oklch(0.74 0.16 295);
  --sans: "Manrope", "Noto Sans TC", -apple-system, system-ui, sans-serif;
  --mono: "JetBrains Mono", "SF Mono", ui-monospace, monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html, body {
  background: #000;
  color: var(--ink);
  font-family: var(--sans);
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  font-feature-settings: "ss01", "ss02", "cv11";
}

deck-stage { background: #000; }

section.slide {
  position: relative;
  width: 1920px;
  height: 1080px;
  background: #000;
  overflow: hidden;
  color: var(--ink);
  font-family: var(--sans);
}

/* Subtle vignette on every slide */
section.slide::after {
  content: "";
  position: absolute; inset: 0;
  pointer-events: none;
  background: radial-gradient(ellipse 90% 70% at 50% 50%, transparent 50%, rgba(0,0,0,0.55) 100%);
  z-index: 60;
}

/* Slide number tag */
.tag {
  position: absolute;
  top: 56px; left: 80px;
  font-family: var(--mono);
  font-size: 26px;
  letter-spacing: 0.16em;
  color: var(--ink-faint);
  text-transform: uppercase;
  z-index: 20;
}
.tag .dot { display: inline-block; width: 6px; height: 6px; border-radius: 50%; background: var(--cyan); margin-right: 12px; vertical-align: middle; transform: translateY(-2px); }

.foot {
  position: absolute;
  bottom: 48px; left: 80px;
  right: 80px;
  display: flex; justify-content: space-between; align-items: center;
  font-family: var(--mono);
  font-size: 24px;
  letter-spacing: 0.14em;
  color: var(--ink-faint);
  z-index: 20;
}
.foot .topic { text-transform: uppercase; }
.foot .crumbs { display: flex; gap: 40px; }
.foot .crumbs span { opacity: 0.4; }
.foot .crumbs span[data-on] { color: var(--ink); opacity: 1; }
.foot .crumbs span[data-on]::before { content: "● "; color: var(--cyan); margin-right: 6px; }

/* ================================
   Animation system
   triggered by [data-deck-active]
   ================================ */
.anim {
  opacity: 0;
  transform: translateY(40px);
  filter: blur(16px);
  transition: opacity 1.2s cubic-bezier(.2,.7,.15,1),
              transform 1.2s cubic-bezier(.2,.7,.15,1),
              filter 1.2s cubic-bezier(.2,.7,.15,1);
}
[data-deck-active] .anim { opacity: 1; transform: none; filter: none; }

.anim-up { transform: translateY(80px); }
.anim-down { transform: translateY(-40px); }
.anim-scale { transform: scale(0.86); transform-origin: 50% 60%; }
.anim-left { transform: translateX(-60px); }
.anim-right { transform: translateX(60px); }
[data-deck-active] .anim-up,
[data-deck-active] .anim-down,
[data-deck-active] .anim-scale,
[data-deck-active] .anim-left,
[data-deck-active] .anim-right { transform: none; }

/* delays in 80ms ticks */
.d1 { transition-delay: .08s; } .d2 { transition-delay: .16s; }
.d3 { transition-delay: .24s; } .d4 { transition-delay: .32s; }
.d5 { transition-delay: .40s; } .d6 { transition-delay: .48s; }
.d7 { transition-delay: .56s; } .d8 { transition-delay: .64s; }
.d9 { transition-delay: .72s; } .d10 { transition-delay: .80s; }
.d11 { transition-delay: .88s; } .d12 { transition-delay: .96s; }
.d13 { transition-delay: 1.04s; } .d14 { transition-delay: 1.12s; }
.d15 { transition-delay: 1.20s; } .d16 { transition-delay: 1.28s; }

/* Hero numerals reveal */
.hero-num {
  display: inline-block;
  font-feature-settings: "tnum";
  letter-spacing: -0.045em;
  background: linear-gradient(180deg, #fff 0%, rgba(255,255,255,0.65) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* Cinematic ambient blobs */
.ambient {
  position: absolute;
  border-radius: 50%;
  filter: blur(120px);
  opacity: 0.55;
  pointer-events: none;
  z-index: 0;
}

/* ================================
   Cover slide
   ================================ */
.cover {
  display: grid;
  grid-template-rows: 1fr auto;
  padding: 160px 120px 110px;
}
.cover .stack { display: flex; flex-direction: column; justify-content: center; gap: 28px; }
.cover .eyebrow {
  font-family: var(--mono);
  font-size: 26px;
  letter-spacing: 0.32em;
  color: var(--cyan);
  text-transform: uppercase;
}
.cover h1 {
  font-size: 168px;
  font-weight: 200;
  letter-spacing: -0.04em;
  line-height: 0.92;
  color: var(--ink);
}
.cover h1 strong {
  font-weight: 700;
  background: linear-gradient(120deg, #fff 20%, var(--cyan) 60%, var(--violet) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.cover .sub-en {
  font-size: 40px;
  font-weight: 300;
  color: var(--ink-dim);
  letter-spacing: -0.01em;
  margin-top: 10px;
}
.cover .meta {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  border-top: 1px solid var(--line);
  padding-top: 32px;
  font-family: var(--mono);
  font-size: 24px;
  color: var(--ink-dim);
  letter-spacing: 0.1em;
}
.cover .meta .week { color: var(--ink); font-size: 28px; }
.cover .authors { text-align: right; line-height: 1.6; }
.cover .authors span { color: var(--ink); }

/* aurora background lines on cover */
.aurora {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(ellipse 80% 50% at 20% 110%, oklch(0.5 0.18 230 / 0.45), transparent 60%),
    radial-gradient(ellipse 60% 40% at 90% -10%, oklch(0.55 0.18 300 / 0.35), transparent 60%);
}

/* ================================
   Agenda
   ================================ */
.agenda {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px 88px;
  padding: 180px 120px 140px;
}
.agenda-head {
  grid-column: 1 / -1;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
}
.agenda-head h2 {
  font-size: 88px;
  font-weight: 200;
  letter-spacing: -0.03em;
  line-height: 1;
}
.agenda-head .en {
  font-family: var(--mono);
  font-size: 18px;
  color: var(--ink-faint);
  letter-spacing: 0.2em;
  text-transform: uppercase;
}
.agenda-item {
  display: grid;
  grid-template-columns: auto 1fr;
  column-gap: 36px;
  align-items: start;
}
.agenda-item .idx {
  font-family: var(--mono);
  font-size: 26px;
  color: var(--cyan);
  letter-spacing: 0.18em;
  padding-top: 14px;
}
.agenda-item h3 {
  font-size: 54px;
  font-weight: 500;
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin-bottom: 18px;
}
.agenda-item ul { list-style: none; }
.agenda-item li {
  font-size: 30px;
  font-weight: 300;
  color: var(--ink-dim);
  line-height: 1.65;
  padding-left: 24px;
  position: relative;
}
.agenda-item li::before {
  content: "";
  position: absolute;
  left: 0; top: 16px;
  width: 10px; height: 1px;
  background: var(--ink-faint);
}

/* ================================
   Part divider
   ================================ */
.divider {
  display: grid;
  grid-template-rows: 1fr auto;
  padding: 140px 120px;
}
.divider .upper { display: flex; flex-direction: column; justify-content: center; gap: 36px; }
.divider .part-num {
  font-family: var(--mono);
  font-size: 26px;
  letter-spacing: 0.4em;
  color: var(--cyan);
}
.divider .part-num .big {
  display: block;
  font-size: 360px;
  font-weight: 200;
  letter-spacing: -0.05em;
  line-height: 0.85;
  color: var(--ink);
  margin-top: 18px;
  background: linear-gradient(180deg, #fff 0%, rgba(255,255,255,0.15) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.divider h2 {
  font-size: 96px;
  font-weight: 300;
  letter-spacing: -0.03em;
  line-height: 1.05;
  max-width: 1500px;
}
.divider h2 em {
  font-style: normal;
  font-weight: 600;
  background: linear-gradient(120deg, var(--cyan) 0%, var(--violet) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.divider .en {
  font-family: var(--mono);
  font-size: 24px;
  letter-spacing: 0.16em;
  color: var(--ink-dim);
  text-transform: uppercase;
  border-top: 1px solid var(--line);
  padding-top: 28px;
  max-width: 1100px;
}

/* ================================
   Reusable slide-content shells
   ================================ */
.h-shell {
  padding: 100px 120px 150px;
  display: grid;
  grid-template-rows: auto 1fr;
  gap: 36px;
  height: 100%;
}
.slide-head .eyebrow {
  font-family: var(--mono);
  font-size: 24px;
  letter-spacing: 0.24em;
  color: var(--cyan);
  text-transform: uppercase;
  margin-bottom: 18px;
}
.slide-head h2 {
  font-size: 80px;
  font-weight: 400;
  letter-spacing: -0.025em;
  line-height: 1.1;
}
.slide-head h2 em {
  font-style: normal;
  font-weight: 600;
}
.slide-head .en {
  font-family: var(--mono);
  font-size: 18px;
  letter-spacing: 0.2em;
  color: var(--ink-faint);
  text-transform: uppercase;
  margin-top: 16px;
}

/* Big-stat grid (slide 1.1) */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 48px;
  align-items: stretch;
}
.stat-cell {
  position: relative;
  padding: 32px 28px 28px;
  border-top: 1px solid var(--line-strong);
  display: grid;
  grid-template-rows: 1fr auto auto;
  row-gap: 14px;
}
.stat-cell .num { align-self: end; }
.stat-cell .label-top {
  position: absolute; top: -16px; left: 0;
  font-family: var(--mono);
  font-size: 26px;
  letter-spacing: 0.14em;
  color: var(--ink-faint);
  background: #000;
  padding-right: 12px;
}
.stat-cell .num {
  font-size: 116px;
  font-weight: 200;
  letter-spacing: -0.05em;
  line-height: 1;
}
.stat-cell .num.accent { color: var(--cyan); }
.stat-cell .num.coral { color: var(--coral); }
.stat-cell .num.amber { color: var(--amber); }
.stat-cell .num.lime { color: var(--lime); }
.stat-cell .role {
  font-size: 36px;
  font-weight: 500;
  margin-top: 0;
  color: var(--ink);
}
.stat-cell .desc {
  font-size: 30px;
  color: var(--ink-dim);
  margin-top: 0;
  line-height: 1.5;
}

.papers {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  margin-top: 12px;
}
.paper {
  border-left: 2px solid var(--cyan);
  padding: 8px 0 8px 32px;
}
.paper.coral { border-color: var(--coral); }
.paper .cite {
  font-family: var(--mono);
  font-size: 24px;
  color: var(--ink-dim);
  letter-spacing: 0.04em;
  margin-bottom: 10px;
}
.paper .point {
  font-size: 28px;
  font-weight: 400;
  line-height: 1.5;
  color: var(--ink);
}
.paper .point b { font-weight: 700; }
.paper .flaw {
  margin-top: 12px;
  font-size: 24px;
  color: var(--ink-dim);
  line-height: 1.45;
}
.paper .flaw::before {
  content: "缺口";
  display: inline-block;
  font-family: var(--mono);
  font-size: 14px;
  letter-spacing: 0.18em;
  color: var(--coral);
  border: 1px solid var(--coral);
  border-radius: 999px;
  padding: 2px 10px;
  margin-right: 12px;
  vertical-align: 3px;
}