:root {
  --bg: #000;
  --fg: #fff;
  --muted: #a3a3a3;
  --line: #262626;
  --panel: #0a0a0a;
  --gutter: clamp(16px, 4vw, 48px);
  --font: -apple-system, BlinkMacSystemFont, "Helvetica Neue", "Inter", "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Microsoft YaHei", Arial, sans-serif;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--bg); color: var(--fg); font-family: var(--font); font-size: 16px; line-height: 1.55; -webkit-font-smoothing: antialiased; overflow-x: hidden; }
a { color: inherit; }
h1, h2, h3 { font-weight: 400; margin: 0; letter-spacing: -0.01em; }
p { margin: 0; }
html[lang^="zh"] .en, html:not([lang^="zh"]) .zh { display: none !important; }
:focus-visible { outline: 2px solid var(--fg); outline-offset: 3px; }

.banner { background: var(--fg); color: var(--bg); font-size: 13px; text-align: center; padding: 6px var(--gutter); }

.top { position: sticky; top: 0; z-index: 20; display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 16px var(--gutter); background: rgba(0,0,0,.82); backdrop-filter: blur(10px); border-bottom: 1px solid var(--line); }
.brand { font-size: 15px; letter-spacing: .22em; text-transform: uppercase; text-decoration: none; font-weight: 500; white-space: nowrap; }
.top nav { display: flex; gap: 28px; align-items: center; font-size: 14px; }
.top nav a { text-decoration: none; color: var(--muted); transition: color .15s; }
.top nav a:hover { color: var(--fg); }
.lang { background: none; border: 0; color: var(--muted); font: inherit; font-size: 14px; cursor: pointer; padding: 4px 2px; }
.lang:hover { color: var(--fg); }
.top nav .nav-cta { color: var(--fg); border: 1px solid var(--fg); padding: 7px 14px; }

.btn { display: inline-flex; align-items: center; gap: 10px; padding: 13px 22px; font: inherit; font-size: 14px; letter-spacing: .04em; text-decoration: none; border: 1px solid var(--fg); border-radius: 0; cursor: pointer; background: none; color: var(--fg); transition: background .15s, color .15s; }
.btn-solid { background: var(--fg); color: var(--bg); }
.btn-solid:hover { background: transparent; color: var(--fg); }
.btn-line:hover { background: var(--fg); color: var(--bg); }
.btn[aria-disabled="true"] { opacity: .35; cursor: not-allowed; pointer-events: none; }
.dur { color: inherit; opacity: .6; font-variant-numeric: tabular-nums; }

.hero { position: relative; padding: 0; height: min(88vh, 860px); min-height: 520px; overflow: hidden; border-bottom: 1px solid var(--line); }
.hero-video { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.hero-shade { position: absolute; inset: 0; background: linear-gradient(to top, rgba(0,0,0,.88) 0%, rgba(0,0,0,.35) 45%, rgba(0,0,0,.15) 100%); }
.hero-text { position: absolute; left: var(--gutter); right: var(--gutter); bottom: clamp(32px, 8vh, 80px); max-width: 900px; }
.hero h1 { font-size: clamp(30px, 5.2vw, 60px); line-height: 1.08; }
.hero-sub { margin-top: 18px; color: #d4d4d4; font-size: clamp(15px, 1.6vw, 18px); max-width: 560px; }
.hero-actions { margin-top: 28px; display: flex; flex-wrap: wrap; gap: 12px; }
.hero-text, .hero-shade { transition: opacity .35s; }
.hero.watching .hero-text, .hero.watching .hero-shade { opacity: 0; pointer-events: none; }
.hero.watching .hero-video { object-fit: contain; background: #000; }
.hero-sound { position: absolute; right: var(--gutter); bottom: clamp(32px, 8vh, 80px); background: rgba(0,0,0,.5); color: var(--fg); border: 1px solid rgba(255,255,255,.5); font: inherit; font-size: 13px; padding: 8px 14px; cursor: pointer; }

section { padding: clamp(64px, 10vw, 120px) var(--gutter); }
.section-head { max-width: 640px; margin-bottom: clamp(36px, 6vw, 64px); }
.section-head h2 { font-size: clamp(26px, 3.4vw, 40px); }
.section-head p { margin-top: 12px; color: var(--muted); }

.sample { display: grid; grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr); gap: clamp(20px, 4vw, 56px); align-items: center; padding: clamp(28px, 4vw, 48px) 0; border-top: 1px solid var(--line); }
.sample-media { position: relative; background: var(--panel); overflow: hidden; }
.sample-media video { background: #000; }
.play { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; gap: 14px; width: 100%; border: 0; background: rgba(0,0,0,.18); color: var(--fg); font: inherit; font-size: 15px; letter-spacing: .04em; cursor: pointer; transition: background .2s; }
.play:hover { background: rgba(0,0,0,.05); }
.play .tri { width: 64px; height: 64px; border: 1px solid var(--fg); background: rgba(0,0,0,.55); display: grid; place-items: center; }
.play .tri::before { content: ""; margin-left: 5px; border-style: solid; border-width: 11px 0 11px 18px; border-color: transparent transparent transparent var(--fg); }
.play .dur { background: rgba(0,0,0,.55); padding: 4px 8px; opacity: 1; }
.play .fail { display: none; background: rgba(0,0,0,.7); padding: 6px 10px; }
.sample-media.failed .play .fail { display: inline; }
.sample-media.failed .play .dur { display: none; }
.sample-media.loading .play .tri { opacity: .45; }
.sample-media.playing .play { display: none; }
.sample-media video { display: block; width: 100%; height: 100%; object-fit: contain; }
.sample-media.landscape { aspect-ratio: 16 / 9; }
.sample-media.portrait { aspect-ratio: 9 / 16; width: min(100%, 340px); justify-self: center; }
.sample.portrait-row { grid-template-columns: minmax(0, 340px) minmax(0, 560px); justify-content: start; }
.sample.portrait-row .sample-media.portrait { width: 100%; }
.sample-text h3 { font-size: clamp(22px, 2.4vw, 30px); }
.discuss { margin-top: 22px; padding: 0 0 3px; background: none; border: 0; border-bottom: 1px solid var(--fg); color: var(--fg); font: inherit; font-size: 14px; letter-spacing: .02em; cursor: pointer; }
.discuss:hover { opacity: .7; }
.sample-text p { margin-top: 12px; color: #d4d4d4; }
.sample-text .fit { color: var(--muted); font-size: 15px; }

.grid { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); border-top: 1px solid var(--line); border-left: 1px solid var(--line); }
.grid li { padding: 28px; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.grid h3 { font-size: 18px; }
.grid p { margin-top: 10px; color: var(--muted); font-size: 15px; }
.tbc { color: #737373; border-bottom: 1px dashed #525252; }


.contact { border-top: 1px solid var(--line); text-align: center; }
.contact h2 { font-size: clamp(30px, 4.6vw, 52px); }
.contact > p { margin: 16px auto 0; color: var(--muted); max-width: 520px; }
.contact-actions { margin-top: 32px; display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; }
.contact-mail { margin-top: 14px !important; font-size: 14px; color: var(--muted) !important; letter-spacing: .02em; }
.contact-note { margin-top: 18px !important; font-size: 13px; color: #737373 !important; }

.foot { display: flex; justify-content: space-between; gap: 16px; padding: 28px var(--gutter); border-top: 1px solid var(--line); color: #737373; font-size: 13px; letter-spacing: .04em; }

.keys-help { max-width: 420px; padding: 22px 24px; border: 1px solid var(--fg); background: #000; color: var(--fg); }
.keys-help::backdrop { background: rgba(0,0,0,.7); }
.keys-help h2 { font-size: 17px; margin-bottom: 14px; }
.keys-help dl { display: grid; grid-template-columns: auto 1fr; gap: 8px 16px; margin: 0; font-size: 14px; }
.keys-help dt { font-weight: 600; }
.keys-help dd { margin: 0; color: #d4d4d4; }

@media (max-width: 860px) {
  .top nav a:not(.nav-cta) { display: none; }
  .top nav { gap: 16px; }
  .sample, .sample.portrait-row { display: flex; flex-direction: column; align-items: stretch; gap: 0; }
  .sample-text { display: contents; }
  .sample-text h3 { order: 0; }
  .sample-text .desc { order: 1; margin: 8px 0 18px; }
  .sample-media { order: 2; }
  .sample.portrait-row .sample-media.portrait { width: min(100%, 340px); align-self: center; }
  .sample-text .fit { order: 3; margin-top: 16px; }
  .discuss { order: 4; align-self: flex-start; }
  .grid { grid-template-columns: 1fr; }
  .hero { height: auto; min-height: 0; }
  .hero-video { position: relative; display: block; height: auto; aspect-ratio: 16 / 9; }
  .hero-shade { display: none; }
  .hero-text { position: static; padding: 28px var(--gutter) 44px; max-width: none; }
  .hero-sound { top: 12px; right: 12px; bottom: auto; }
  .hero.watching .hero-text { opacity: 1; pointer-events: auto; }
}
@media (max-width: 480px) {
  .foot { flex-direction: column; }
  .top nav .nav-cta { padding: 6px 10px; font-size: 13px; }
  .brand { letter-spacing: .14em; font-size: 13px; }
  .top { padding: 14px var(--gutter); }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }