/* ═════════════════════════════════════════════════
   TrainingVideo · Midnight Studio
   tokens → base → nav → sections → motion → media
   ═════════════════════════════════════════════════ */

/* ─── tokens ─── */
:root {
  --bg: #0B0F14;
  --bg-raised: #11161D;
  --line: #1E2732;
  --text: #E8EDF2;
  --text-dim: #8A97A6;
  --accent: #2DD4BF;
  --accent-deep: #14B8A6;
  --warn: #F87171;

  --font-display: "TV Serif SC", "Noto Serif SC", serif;
  --font-body: system-ui, "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;

  --space-1: 8px; --space-2: 16px; --space-3: 24px;
  --space-4: 40px; --space-5: 64px; --space-6: 104px;
  --maxw: 1120px;

  --t-fast: 160ms; --t-base: 320ms;
  --ease: cubic-bezier(.16, 1, .3, 1);
  --radius: 12px;
}

@font-face {
  font-family: "TV Serif SC";
  src: url("../fonts/display-subset.woff2") format("woff2");
  font-display: swap;
  font-weight: 400;
}

/* ─── base ─── */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
img, video { display: block; max-width: 100%; height: auto; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.display {
  font-family: var(--font-display);
  font-weight: 400;
  letter-spacing: 0.04em;
  line-height: 1.25;
  margin: 0;
}
.mono { font-family: ui-monospace, "Cascadia Mono", Consolas, monospace; font-size: .92em; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 var(--space-3); }
.wrap-narrow { max-width: 760px; }

.sec { padding: var(--space-6) 0; }
.sec-alt { background: var(--bg-raised); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }

.sec-head { max-width: 640px; margin-bottom: var(--space-5); }
.sec-head .display { font-size: clamp(1.7rem, 3.6vw, 2.6rem); }
.sec-sub { color: var(--text-dim); margin: var(--space-2) 0 0; }

.eyebrow {
  font-family: ui-monospace, Consolas, monospace;
  font-size: .75rem;
  letter-spacing: .22em;
  color: var(--accent);
  margin: 0 0 var(--space-2);
  text-transform: uppercase;
}

/* ─── buttons ─── */
.btn {
  display: inline-block;
  font: inherit;
  font-weight: 600;
  padding: 12px 28px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform var(--t-fast) var(--ease), opacity var(--t-fast) var(--ease);
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-primary { background: var(--accent); color: #06251F; }
.btn-primary:hover { background: var(--accent-deep); color: #06251F; }
.btn-ghost { border-color: var(--line); color: var(--text); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn-lg { padding: 16px 40px; font-size: 1.1rem; }

/* ─── nav ─── */
.nav {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; justify-content: space-between;
  max-width: var(--maxw); margin: 0 auto;
  padding: var(--space-2) var(--space-3);
  background: rgba(11, 15, 20, .82);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav-brand {
  font-family: var(--font-display);
  font-size: 1.15rem;
  letter-spacing: 0.04em;
  color: var(--text);
}
.nav-links { display: flex; align-items: center; gap: var(--space-3); }
.nav-links > a:not(.btn) { color: var(--text-dim); font-size: .95rem; }
.nav-links > a:not(.btn):hover { color: var(--text); text-decoration: none; }
.nav-links > a[aria-current] { color: var(--accent); }
.nav-cta-wrap { margin-left: var(--space-2); }
.nav-cta-wrap .btn { padding: 8px 20px; }

.nav-fold { display: none; position: relative; }
.nav-fold summary {
  list-style: none;
  display: flex; flex-direction: column; gap: 5px;
  padding: 8px; cursor: pointer;
}
.nav-fold summary::-webkit-details-marker { display: none; }
.nav-fold summary span {
  width: 22px; height: 2px; background: var(--text); border-radius: 1px;
}
.nav-fold[open] summary span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-fold[open] summary span:nth-child(2) { opacity: 0; }
.nav-fold[open] summary span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
.nav-fold-panel {
  position: absolute; right: 0; top: calc(100% + 8px);
  display: flex; flex-direction: column; gap: var(--space-2);
  min-width: 180px;
  padding: var(--space-3);
  background: var(--bg-raised);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.nav-fold-panel a:not(.btn) { color: var(--text-dim); }
.nav-fold-panel a:not(.btn):hover { color: var(--text); }

/* ─── hero ─── */
.hero {
  min-height: 92dvh;
  display: flex; align-items: center;
  padding: var(--space-5) 0 var(--space-6);
}
.hero-inner {
  max-width: var(--maxw); margin: 0 auto;
  padding: 0 var(--space-3);
  display: grid;
  grid-template-columns: 11fr 13fr;
  gap: clamp(var(--space-4), 6vw, var(--space-6));
  align-items: center;
  width: 100%;
}
.hero-copy .display {
  font-size: clamp(2.2rem, 5.2vw, 4rem);
}
.hero-sub {
  color: var(--text-dim);
  font-size: clamp(1rem, 1.4vw, 1.15rem);
  margin: var(--space-3) 0 var(--space-4);
}
.hero-actions { display: flex; flex-wrap: wrap; gap: var(--space-2); }

/* player · 全页唯一发光体 */
.player {
  position: relative;
  margin: 0;
  border-radius: var(--radius);
  border: 1px solid var(--accent-deep);
  box-shadow: 0 0 56px rgba(45, 212, 191, .10);
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background: #000;
}
.player video { width: 100%; height: 100%; object-fit: contain; }
.player-mask {
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  background: rgba(5, 8, 12, .35);
  border: 0; cursor: pointer;
  padding: 0;
  transition: opacity var(--t-base) var(--ease);
}
.player-mask.is-hidden { opacity: 0; pointer-events: none; }
.player-btn {
  display: grid; place-items: center;
  width: 72px; height: 72px;
  border-radius: 50%;
  background: var(--accent);
  color: #06251F;
  transition: transform var(--t-fast) var(--ease);
}
.player-mask:hover .player-btn { transform: scale(1.08); }
.player-tag {
  position: absolute; right: var(--space-2); bottom: var(--space-2);
  font-family: ui-monospace, Consolas, monospace;
  font-size: .75rem;
  color: var(--text);
  background: rgba(11, 15, 20, .78);
  padding: 4px 10px;
  border-radius: 6px;
  border: 1px solid var(--line);
}

/* ─── pipeline ─── */
.pipe {
  list-style: none;
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  align-items: stretch;
  gap: var(--space-2);
  margin: 0; padding: 0;
}
.pipe-stage {
  background: var(--bg-raised);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: var(--space-3);
}
.pipe-num {
  font-size: 2.6rem;
  color: var(--accent);
  line-height: 1;
}
.pipe-tag {
  display: block;
  font-family: ui-monospace, Consolas, monospace;
  font-size: .7rem;
  letter-spacing: .14em;
  color: var(--text-dim);
  margin: var(--space-2) 0 4px;
}
.pipe-stage h3 { font-size: 1.05rem; margin: 0 0 var(--space-1); }
.pipe-stage p { font-size: .92rem; color: var(--text-dim); margin: 0; }
.pipe-arrow {
  align-self: center;
  color: var(--accent);
  flex-shrink: 0;
}

.gate {
  display: flex; gap: var(--space-2);
  align-items: flex-start;
  margin-top: var(--space-4);
  padding: var(--space-3);
  border: 1px solid rgba(248, 113, 113, .35);
  border-radius: var(--radius);
}
.gate-icon { color: var(--warn); flex-shrink: 0; margin-top: 4px; }
.gate p { margin: 0; font-size: .95rem; color: var(--text-dim); }
.gate strong { color: var(--warn); font-weight: 600; }

/* ─── features bento: 1 大 + 4 中 + 1 窄 ─── */
.bento {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-template-areas:
    "large large mid1 mid2"
    "large large mid3 narrow";
  gap: var(--space-3);
}
.b-large { grid-area: large; }
.b-narrow { grid-area: narrow; }
.b-cell {
  background: var(--bg-raised);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: var(--space-3);
  overflow: hidden;
  display: flex; flex-direction: column; gap: var(--space-2);
}
.b-cell h3 { font-size: 1.05rem; margin: 0; }
.b-cell p { font-size: .92rem; color: var(--text-dim); margin: 0; }
.b-cell img {
  border-radius: 8px;
  border: 1px solid var(--line);
  width: 100%;
  order: -1;
}
.big-num { font-size: 2.2rem; color: var(--accent); margin-right: 8px; }
.b-note {
  margin-top: auto;
  border-top: 1px solid var(--line);
  padding-top: var(--space-2);
}
.b-note .mono { color: var(--accent); }
.shot-slot {
  flex: 1;
  min-height: 260px;
  display: grid; place-items: center;
  text-align: center;
  border: 1px dashed var(--line);
  border-radius: 8px;
  color: var(--text-dim);
  font-size: .9rem;
  padding: var(--space-3);
}

/* ─── scenes ─── */
.scene-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-3);
}
.scene {
  background: var(--bg-raised);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: var(--space-3);
  display: flex; flex-direction: column; gap: var(--space-1);
}
.scene h3 { font-size: 1.05rem; margin: 0 0 var(--space-1); }
.scene p { font-size: .92rem; color: var(--text-dim); margin: 0; }
.scene-out {
  margin-top: auto;
  padding-top: var(--space-2);
  border-top: 1px solid var(--line);
  font-family: ui-monospace, Consolas, monospace;
  font-size: .8rem;
  color: var(--accent);
}

/* ─── data band ─── */
.sec-data { padding: var(--space-5) 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.band {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  margin: 0;
}
.band-item { text-align: center; padding: 0 var(--space-2); }
.band-item + .band-item { border-left: 1px solid var(--line); }
.band dt { font-size: clamp(2rem, 4.5vw, 3rem); color: var(--text); }
.band dd { margin: 4px 0 0; color: var(--text-dim); font-size: .9rem; }

/* ─── faq ─── */
.faq-list { display: flex; flex-direction: column; }
.faq-list details {
  border-bottom: 1px solid var(--line);
}
.faq-list details:first-child { border-top: 1px solid var(--line); }
.faq-list summary {
  list-style: none;
  cursor: pointer;
  padding: var(--space-3) 0;
  font-weight: 600;
  display: flex; justify-content: space-between; align-items: center; gap: var(--space-2);
}
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after {
  content: "+";
  font-size: 1.3rem;
  color: var(--text-dim);
  flex-shrink: 0;
  transition: transform var(--t-fast) var(--ease);
}
.faq-list details[open] summary::after { transform: rotate(45deg); }
.faq-list details p { margin: 0 0 var(--space-3); color: var(--text-dim); max-width: 620px; }

/* ─── cta ─── */
.sec-cta { text-align: center; }
.cta-line { font-size: clamp(1.9rem, 4.5vw, 3.2rem); }
.cta-contact { margin-top: var(--space-5); }
.cta-wechat { margin: var(--space-3) 0 0; color: var(--text-dim); }
.cta-wechat .mono { color: var(--text); }
.cta-note { margin: var(--space-1) 0 0; font-size: .85rem; color: var(--text-dim); }

/* ─── footer ─── */
.footer {
  border-top: 1px solid var(--line);
  padding: var(--space-4) 0;
  color: var(--text-dim);
  font-size: .85rem;
}
.footer p { margin: 0 0 var(--space-1); }
.footer a { color: var(--text-dim); text-decoration: underline; }
.footer a:hover { color: var(--accent); }

/* ─── focus(键盘可达性) ─── */
a:focus-visible, .btn:focus-visible,
.faq-list summary:focus-visible, .nav-fold summary:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

/* ─── motion(契约:仅 .js 下激活入场前态) ─── */
.js [data-reveal]:not(.is-in) {
  opacity: 0;
  transform: translateY(24px);
}
.js [data-reveal] {
  transition: opacity var(--t-base) var(--ease), transform var(--t-base) var(--ease);
  transition-delay: calc(var(--i, 0) * 150ms);
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .js [data-reveal]:not(.is-in) { opacity: 1; transform: none; }
  .js [data-reveal] { transition: none; }
  .btn, .player-btn, .player-mask { transition: none; }
}

/* ─── media ─── */
@media (max-width: 900px) {
  .hero-inner { grid-template-columns: 1fr; }
  .hero { min-height: auto; padding-top: var(--space-5); }
  .pipe { grid-template-columns: 1fr; }
  .pipe-arrow { display: none; }
  .bento {
    grid-template-columns: 1fr 1fr;
    grid-template-areas: "large large" "mid1 mid2" "mid3 narrow";
  }
  .scene-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 640px) {
  .nav-links { display: none; }
  .nav-fold { display: block; }
  .bento {
    grid-template-columns: 1fr;
    grid-template-areas: "large" "mid1" "mid2" "mid3" "narrow";
  }
  .scene-grid { grid-template-columns: 1fr; }
  .band { grid-template-columns: 1fr 1fr; gap: var(--space-3) 0; }
  .band-item:nth-child(3) { border-left: 0; }
  .sec { padding: var(--space-5) 0; }
}