:root {
  --bg: #000;
  --bg-2: #0b0b0d;
  --card: #141416;
  --card-2: #1c1c1f;
  --line: rgba(255,255,255,.09);
  --text: #f5f5f7;
  --muted: #a1a1a6;
  --dim: #6e6e73;
  --accent: #2997ff;
  --accent-2: #64d2ff;
  --radius: 22px;
  --max: 1120px;
  --ease: cubic-bezier(.23, 1, .32, 1);
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  font-size: 17px; line-height: 1.6; -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility;
}
img { display: block; max-width: 100%; height: auto; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 22px; }

/* nav */
nav {
  position: sticky; top: 0; z-index: 10; height: 52px;
  background: rgba(0,0,0,.72); -webkit-backdrop-filter: saturate(180%) blur(20px); backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--line);
}
nav .wrap { display: flex; align-items: center; height: 100%; gap: 28px; }
nav .brand { font-weight: 600; font-size: 19px; letter-spacing: -.01em; color: var(--text); display: flex; align-items: center; gap: 9px; }
nav .brand:hover { text-decoration: none; }
nav .links { display: flex; gap: 24px; margin-left: auto; font-size: 14px; }
nav .links a { color: var(--muted); }
nav .links a:hover { color: var(--text); text-decoration: none; }
nav .lang { font-size: 14px; color: var(--muted); }
nav .lang:hover { color: var(--text); text-decoration: none; }
nav .cta { font-size: 14px; padding: 6px 14px; border-radius: 980px; background: var(--accent); color: #fff; }
nav .cta:hover { text-decoration: none; background: #0077ed; }

/* hero */
.hero { text-align: center; padding: 96px 0 40px; overflow: hidden; }
.eyebrow { color: var(--muted); font-size: 19px; font-weight: 600; letter-spacing: .01em; margin: 0 0 10px; }
h1 {
  font-size: clamp(44px, 8vw, 92px); line-height: 1.04; letter-spacing: -.035em; font-weight: 700; margin: 0;
  background: linear-gradient(180deg, #fff 30%, #b9c3d0 100%); -webkit-background-clip: text; background-clip: text; color: transparent;
}
.lede { font-size: clamp(19px, 2.3vw, 24px); color: var(--muted); max-width: 720px; margin: 22px auto 0; line-height: 1.45; }
.lede strong { color: var(--text); font-weight: 600; }
.actions { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; margin-top: 34px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 13px 26px; border-radius: 980px; font-size: 17px; font-weight: 500;
  transition: transform .18s var(--ease), background .2s ease;
}
.btn:hover { text-decoration: none; }
.btn:active { transform: scale(.97); }
.btn.primary { background: var(--accent); color: #fff; }
.btn.primary:hover { background: #0077ed; }
.btn.ghost { color: var(--accent); border: 1px solid rgba(41,151,255,.5); }
.btn.ghost:hover { background: rgba(41,151,255,.1); }

/* tv frame */
.tv { position: relative; margin: 64px auto 0; max-width: 1040px; }
.tv .screen {
  position: relative; border-radius: 14px; overflow: hidden; background: #000;
  box-shadow: 0 0 0 10px #111, 0 0 0 11px #2a2a2d, 0 40px 120px -20px rgba(41,151,255,.25), 0 30px 80px rgba(0,0,0,.8);
}
.tv .screen img { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; }
.compare { --x: 0%; cursor: ew-resize; touch-action: pan-y; user-select: none; -webkit-user-select: none; outline: none; }
.compare img { -webkit-user-drag: none; pointer-events: none; }
.compare .before { position: absolute; inset: 0; height: 100%; clip-path: inset(0 0 0 var(--x)); }
.compare .divider { transition: opacity .25s ease; position: absolute; top: 0; bottom: 0; left: var(--x); width: 2px; margin-left: -1px; background: rgba(255,255,255,.9); box-shadow: 0 0 18px rgba(0,0,0,.5); }
.compare .knob {
  position: absolute; top: 50%; left: 50%; width: 44px; height: 44px; margin: -22px 0 0 -22px; border-radius: 50%;
  display: grid; place-items: center; color: #111; background: rgba(255,255,255,.92);
  box-shadow: 0 6px 24px rgba(0,0,0,.45); -webkit-backdrop-filter: blur(10px); backdrop-filter: blur(10px);
  transition: transform .2s var(--ease);
}
.compare:hover .knob, .compare:focus-visible .knob { transform: scale(1.08); }
.compare-legend { display: flex; flex-direction: column; align-items: center; gap: 10px; margin-top: 22px; }
.replay {
  display: inline-flex; align-items: center; gap: 6px; white-space: nowrap; appearance: none; font: inherit; cursor: pointer;
  font-size: 14px; font-weight: 500; color: var(--muted); background: transparent; border: 1px solid var(--line);
  border-radius: 980px; padding: 7px 16px; transition: color .2s ease, border-color .2s ease, transform .15s var(--ease);
}
.replay:hover { color: var(--text); border-color: rgba(255,255,255,.22); }
.replay:active { transform: scale(.96); }
.compare-hint { color: var(--dim); font-size: 13px; }
@media (hover: none) { .compare-hint { display: none; } }
.tv .stand { width: 26%; height: 14px; margin: 18px auto 0; border-radius: 0 0 10px 10px; background: linear-gradient(#2a2a2d, #141416); }
.glow { position: absolute; inset: -10% -20% auto; height: 70%; z-index: -1; filter: blur(80px); opacity: .55;
  background: radial-gradient(40% 50% at 30% 50%, #1f7a6a, transparent 70%), radial-gradient(40% 50% at 70% 40%, #3b2a9c, transparent 70%); }

/* sections */
section { padding: 110px 0; }
section.alt { background: var(--bg-2); }
.head { text-align: center; max-width: 760px; margin: 0 auto 56px; }
h2 { font-size: clamp(34px, 5vw, 56px); line-height: 1.08; letter-spacing: -.03em; margin: 0; font-weight: 700; }
.head p { color: var(--muted); font-size: 21px; margin: 18px 0 0; line-height: 1.5; }

.feature { display: grid; grid-template-columns: 1.35fr 1fr; gap: 56px; align-items: center; }
.feature + .feature { margin-top: 110px; }
.feature.flip { grid-template-columns: 1fr 1.35fr; }
.feature.flip .shot { order: 2; }
.feature h3 { font-size: clamp(28px, 3.4vw, 40px); line-height: 1.12; letter-spacing: -.025em; margin: 0 0 16px; }
.feature p { color: var(--muted); margin: 0 0 12px; }
.feature p strong { color: var(--text); font-weight: 600; }
.shot { border-radius: 16px; overflow: hidden; box-shadow: 0 0 0 1px var(--line), 0 30px 70px rgba(0,0,0,.6); background: #000; }
.shot img { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; }
.sub { font-size: clamp(28px, 3.4vw, 40px); line-height: 1.12; letter-spacing: -.025em; margin: 0 0 16px; }
.muted { color: var(--muted); }
.kicker { color: var(--accent-2); font-size: 15px; font-weight: 600; margin: 0 0 10px; letter-spacing: .02em; }

.gallery { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.gallery figure { margin: 0; }
.gallery figcaption { color: var(--dim); font-size: 14px; margin-top: 10px; text-align: center; }

.phone-row { display: grid; grid-template-columns: 1.35fr 1fr; gap: 56px; align-items: center; }
.phone { width: min(300px, 100%); margin: 0 auto; border-radius: 42px; padding: 12px; background: #111; box-shadow: 0 0 0 1px #2a2a2d, 0 30px 80px rgba(0,0,0,.7); }
.phone img { border-radius: 32px; }

.grid3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.tile { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 30px 28px; }
.tile .ic { width: 40px; height: 40px; border-radius: 11px; display: grid; place-items: center; margin-bottom: 18px; background: rgba(41,151,255,.14); color: var(--accent-2); }
.tile h4 { font-size: 21px; margin: 0 0 8px; letter-spacing: -.01em; }
.tile p { margin: 0; color: var(--muted); font-size: 16px; line-height: 1.55; }

.devices { display: flex; justify-content: center; gap: 14px; flex-wrap: wrap; margin-top: 40px; }
.chip { border: 1px solid var(--line); background: var(--card); border-radius: 980px; padding: 8px 16px; font-size: 15px; color: var(--muted); }
.chip b { color: var(--text); font-weight: 600; }
a.chip-link { color: var(--muted); transition: border-color .2s ease, color .2s ease; }
a.chip-link b { color: var(--accent); }
a.chip-link:hover { text-decoration: none; border-color: rgba(41,151,255,.5); color: var(--text); }

/* install */
.install { max-width: 860px; margin: 0 auto; }
.field { display: flex; align-items: center; gap: 12px; background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 6px 6px 6px 18px; margin-bottom: 22px; }
.field label { color: var(--muted); font-size: 15px; white-space: nowrap; }
.field input { flex: 1; min-width: 0; background: transparent; border: 0; color: var(--text); font: inherit; font-size: 17px; padding: 10px 4px; outline: none; }
.field input::placeholder { color: var(--dim); }
.field .opt { display: flex; align-items: center; gap: 8px; color: var(--muted); font-size: 14px; padding-right: 12px; white-space: nowrap; cursor: pointer; }
.tabs { display: inline-flex; background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 4px; gap: 4px; margin-bottom: 18px; }
.tabs button {
  appearance: none; border: 0; background: transparent; color: var(--muted); font: inherit; font-size: 15px; font-weight: 500;
  padding: 8px 18px; border-radius: 9px; cursor: pointer; transition: background .2s ease, color .2s ease;
}
.tabs button { display: inline-flex; align-items: center; gap: 7px; }
.tabs .logo { display: block; flex: none; height: 14px; aspect-ratio: 1; background: currentColor; -webkit-mask: var(--logo) center / contain no-repeat; mask: var(--logo) center / contain no-repeat; }
.tabs .logo.xiaomi { --logo: url(img/brands/xiaomi.svg); height: 16px; }
.tabs .logo.android { --logo: url(img/brands/android.svg); height: 18px; }
.tabs .logo.tcl { --logo: url(img/brands/tcl.svg); height: 17px; aspect-ratio: 1.678; }
.tabs .logo.haier { --logo: url(img/brands/haier.svg); height: 13px; aspect-ratio: 3.247; }
.tabs .logo.oppo { --logo: url(img/brands/oppo.svg); height: 11px; aspect-ratio: 4.207; }
.tabs button[aria-selected="true"] { background: var(--card-2); color: var(--text); box-shadow: 0 1px 3px rgba(0,0,0,.4); }
.panel { display: none; }
.panel.on { display: block; }
.panel > p { color: var(--muted); margin: 0 0 14px; }
.panel > p.note { color: var(--dim); margin: 14px 0 0; }
.code { position: relative; background: #0d0d0f; border: 1px solid var(--line); border-radius: 16px; }
.code pre {
  margin: 0; padding: 22px 22px 22px; overflow-x: auto; white-space: pre-wrap; word-break: break-word;
  font: 14px/1.65 ui-monospace, "SF Mono", Menlo, Consolas, monospace; color: #e6e6e9;
}
.code .copy {
  position: absolute; top: 12px; right: 12px; appearance: none; border: 1px solid var(--line); background: var(--card-2);
  color: var(--text); font: inherit; font-size: 13px; padding: 6px 12px; border-radius: 8px; cursor: pointer;
  transition: background .2s ease, transform .15s var(--ease);
}
.code .copy:hover { background: #2a2a2e; }
.code .copy:active { transform: scale(.96); }
.note { color: var(--dim); font-size: 14px; margin-top: 14px; }
.step { display: flex; align-items: center; gap: 12px; font-size: 21px; letter-spacing: -.01em; margin: 44px 0 14px; }
.step:first-child { margin-top: 0; }
.step span { flex: none; width: 28px; height: 28px; border-radius: 50%; background: var(--card-2); color: var(--text); font-size: 14px; font-weight: 600; display: grid; place-items: center; }
.panel b { color: var(--text); font-weight: 600; }
.panel a b { color: inherit; }
.hint { color: var(--muted); margin: 0 0 14px; }
.agents { display: flex; flex-wrap: wrap; gap: 8px; list-style: none; padding: 0; margin: 0 0 14px; }
.agents li { display: flex; align-items: center; gap: 8px; padding: 6px 14px 6px 8px; border: 1px solid var(--line); border-radius: 980px; background: var(--card); color: var(--text); font-size: 15px; line-height: 1.3; }
.agents img { width: 20px; height: 20px; flex: none; }

details { border-bottom: 1px solid var(--line); padding: 18px 0; }
details summary { cursor: pointer; font-size: 19px; font-weight: 600; list-style: none; display: flex; justify-content: space-between; gap: 16px; }
details summary::after { content: "+"; color: var(--muted); font-weight: 400; transition: transform .25s var(--ease); }
details[open] summary::after { transform: rotate(45deg); }
details p { color: var(--muted); margin: 12px 0 0; }

footer { border-top: 1px solid var(--line); padding: 40px 0 60px; color: var(--dim); font-size: 13px; line-height: 1.7; }
footer .wrap { display: flex; justify-content: space-between; gap: 24px; flex-wrap: wrap; }
footer a { color: var(--muted); }

.reveal { opacity: 0; transform: translateY(24px); transition: opacity .9s var(--ease), transform .9s var(--ease); }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
}

@media (max-width: 860px) {
  nav .links { display: none; }
  nav .lang { margin-left: auto; }
  .hero { padding-top: 64px; }
  section { padding: 80px 0; }
  .feature, .feature.flip, .phone-row { grid-template-columns: 1fr; gap: 28px; }
  .feature.flip .shot { order: 0; }
  .feature + .feature { margin-top: 72px; }
  .grid3, .gallery { grid-template-columns: 1fr; }
  .field { flex-wrap: wrap; padding: 10px 14px; }
  .field .opt { padding: 4px 0 6px; }
  .tabs[data-tabs="brand"] { display: flex; }
  .tabs[data-tabs="brand"] button { flex: 1 1 auto; justify-content: center; padding: 8px; }
  .compare-legend { margin-top: 18px; }
  .compare .knob { width: 34px; height: 34px; margin: -17px 0 0 -17px; }
}
@media (max-width: 480px) {
  .tabs .logo.xiaomi, .tabs .logo.android { display: none; }
}