:root {
  --ink: #172f3f;
  --ink-soft: #586a75;
  --teal: #087286;
  --teal-line: #b9d7dc;
  --orange: #e6621e;
  --paper: #ffffff;
  --wash: #f4f8f9;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}

.page { width: min(1180px, calc(100% - 40px)); margin: 0 auto; }
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 26px 0;
  border-bottom: 2px solid var(--teal-line);
}
.brand { color: var(--ink); font-size: 1rem; font-weight: 800; text-decoration: none; }
.back { color: var(--teal); font-size: 0.9rem; font-weight: 700; text-decoration: none; }
.brand:hover, .back:hover { color: var(--orange); }
main { padding: 46px 0 64px; }
.number { margin: 0 0 12px; color: var(--orange); font: 800 0.82rem ui-monospace, SFMono-Regular, Menlo, monospace; letter-spacing: 0.12em; }
h1 { margin: 0; color: var(--teal); font-size: clamp(2.5rem, 7vw, 5.5rem); line-height: 1; letter-spacing: -0.05em; }
.work-name { margin: 16px 0 30px; color: var(--ink-soft); font-size: clamp(1rem, 2.5vw, 1.4rem); line-height: 1.5; }
.player-shell { padding: 10px; border: 1px solid var(--teal-line); background: var(--wash); box-shadow: 0 24px 60px rgba(24, 57, 72, 0.12); }
video { display: block; width: 100%; max-height: min(72vh, 760px); background: #0d1d26; object-fit: contain; }
.meta { display: flex; align-items: center; justify-content: space-between; gap: 20px; margin-top: 20px; padding-top: 17px; border-top: 1px solid var(--teal-line); color: var(--ink-soft); font-size: 0.84rem; }
.work-nav { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 10px; }
.nav-button { display: inline-flex; align-items: center; min-height: 40px; padding: 9px 14px; border: 1px solid var(--teal-line); color: var(--teal); background: #fff; font-weight: 750; text-decoration: none; transition: color 160ms ease, border-color 160ms ease, background 160ms ease; }
.nav-button.next { color: #fff; border-color: var(--teal); background: var(--teal); }
.nav-button:hover { color: #fff; border-color: var(--orange); background: var(--orange); }
@media (max-width: 700px) {
  .page { width: min(100% - 24px, 620px); }
  main { padding-top: 34px; }
  .player-shell { padding: 4px; }
  .meta { align-items: flex-start; flex-direction: column; }
  .work-nav { width: 100%; justify-content: stretch; }
  .nav-button { flex: 1; justify-content: center; }
}