:root {
  color-scheme: dark;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: #0a0b10;
  color: #f1f2fb;
  --line: #252735;
  --muted: #a0a4bb;
  --accent: #c3c7ff;
  --surface: #10121a;
}
* { box-sizing: border-box; }
html { -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility; }
body {
  margin: 0;
  background:
    radial-gradient(circle at 38px 31px, #e0e3ff88 0.7px, transparent 1.5px) 0 0 / 223px 187px fixed,
    radial-gradient(circle at 104px 79px, #b6bbf570 0.6px, transparent 1.3px) 0 0 / 163px 229px fixed,
    radial-gradient(circle at 23px 104px, #939ee760 0.5px, transparent 1.2px) 0 0 / 129px 147px fixed,
    radial-gradient(circle at 155px 119px, #d6ddff88 0.8px, #9eabed2c 1.5px, transparent 3px) 0 0 / 311px 257px fixed,
    radial-gradient(ellipse at 18% 12%, #242d562b, transparent 52%),
    radial-gradient(ellipse at 80% 40%, #30234c3d, transparent 53%),
    #090a13;
}
::selection { background: #4b52a0; color: #fff; }
a { color: inherit; text-decoration: none; }
button, a { font: inherit; }
button { cursor: pointer; }
a:focus-visible, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 4px; }
.nav, main, .footer { width: min(1120px, calc(100% - 56px)); margin-inline: auto; }

/* twinkling star layer, filled by site.js */
.sky { position: fixed; inset: 0; z-index: -1; pointer-events: none; overflow: hidden; }
.sky i {
  position: absolute; width: 2px; height: 2px; border-radius: 50%;
  background: #dfe3ff; animation: twinkle 6s ease-in-out infinite;
}
@keyframes twinkle {
  0%, 100% { transform: scale(.5); opacity: .12; }
  50% { transform: scale(1.15); opacity: .85; }
}

.nav-wrap {
  position: sticky; top: 0; z-index: 5;
  background: #0a0b10c9; backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--line);
}
.nav, .footer { display: flex; justify-content: space-between; align-items: center; gap: 16px; }
.nav { height: 74px; }
.wordmark { display: flex; align-items: center; gap: 9px; font-size: 20px; font-weight: 690; letter-spacing: -.055em; }
.wordmark img { border-radius: 9px; }
:lang(zh) .wordmark { letter-spacing: .02em; }
.nav-links { display: flex; gap: 6px; font-size: 14px; color: var(--muted); }
.nav-links a { padding: 8px 13px; border-radius: 999px; transition: color .2s, background .2s; }
.nav-links a:hover { color: #f1f2fb; background: #1b1e34; }
.nav-actions { display: flex; gap: 8px; align-items: center; }
.quiet {
  border: 1px solid var(--line); background: #12141c; color: #c9cbdb; border-radius: 999px;
  padding: 9px 15px; font-size: 13px; white-space: nowrap; display: inline-block;
  transition: border-color .2s, color .2s, background .2s;
}
.quiet:hover { border-color: #6b7097; color: #f1f2fb; }
.primary {
  border: 1px solid #bec2ff; background: #c3c7ff; color: #171931; padding: 12px 22px;
  border-radius: 999px; font-weight: 700; display: inline-block;
  box-shadow: 0 8px 26px #8b94f027; transition: background .2s, transform .2s, box-shadow .2s;
}
.primary:hover { background: #d7daff; transform: translateY(-1px); box-shadow: 0 12px 32px #8b94f040; }
.eyebrow { color: var(--accent); font-size: 12px; font-weight: 700; letter-spacing: .16em; margin: 0 0 20px; }
h1, h2, h3, p, ol, ul { margin: 0; }
h1 { font-size: clamp(43px, 6.3vw, 84px); font-weight: 690; letter-spacing: -.08em; line-height: 1.08; }
:lang(zh) h1 { letter-spacing: -.07em; }
h1 .accent {
  background: linear-gradient(94deg, #a8aef8 8%, #dcc9ff 48%, #8fb2ff 90%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
h2 { font-size: clamp(26px, 3.6vw, 40px); font-weight: 690; letter-spacing: -.05em; line-height: 1.2; max-width: 640px; }
.lead { margin-top: 23px; max-width: 460px; color: var(--muted); font-size: 16px; line-height: 1.75; }
main > section { padding-block: clamp(60px, 9vw, 108px); }
main > section:not(.hero) { border-top: 1px solid var(--line); }
section[id] { scroll-margin-top: 92px; }

/* ---------- hero ---------- */
.hero {
  display: grid; grid-template-columns: 1.05fr .95fr; gap: clamp(28px, 5vw, 72px); align-items: center;
  padding-top: clamp(48px, 7vw, 88px); position: relative;
}
.hero::before {
  content: ""; position: absolute; inset: -10% -20% auto; height: 90%; pointer-events: none;
  background: radial-gradient(ellipse 60% 55% at 72% 42%, #6d76e818, transparent 70%);
}
.hero-copy { position: relative; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 30px; }

.orbit {
  position: relative; display: grid; place-items: center; isolation: isolate; overflow: hidden;
  aspect-ratio: 1.16; border-radius: 28px; border: 1px solid #24263a;
  background: radial-gradient(ellipse at 50% 47%, #20264c 0%, #121529 41%, #10121c 72%);
  transform: perspective(900px) rotateX(var(--tilt-x, 0deg)) rotateY(var(--tilt-y, 0deg));
  transition: transform .5s cubic-bezier(.2, .7, .3, 1);
  box-shadow: 0 30px 90px #00000059, inset 0 1px 0 #ffffff0d;
}
.orbit::before, .orbit::after {
  content: ""; position: absolute; pointer-events: none; border-radius: 50%; aspect-ratio: 1;
  width: 66%; border: 1px solid transparent;
}
.orbit::before { border-color: #9299fa38 transparent #9299fa38 transparent; animation: spin 22s linear infinite; }
.orbit::after { width: 86%; border-color: transparent #9299fa26 transparent #9299fa26; animation: spin 38s linear infinite reverse; }
@keyframes spin { to { transform: rotate(1turn); } }
.orbit svg { width: 100%; height: 100%; position: relative; animation: float 8s ease-in-out infinite; }
@keyframes float { 50% { transform: translateY(-9px); } }
.orbit .halo { animation: breathe 5.5s ease-in-out infinite; }
@keyframes breathe { 50% { opacity: .55; } }
.orbit-pill {
  position: absolute; bottom: 7%; display: flex; align-items: center; gap: 9px; color: #d9dcf7;
  border: 1px solid #393d5b; background: #121528e6; border-radius: 30px; padding: 8px 14px; font-size: 12px;
  backdrop-filter: blur(6px);
}
.float-chip {
  position: absolute; display: flex; align-items: center; gap: 8px; padding: 7px 12px;
  border: 1px solid #393d5b; background: #121528d9; border-radius: 999px;
  font-size: 11.5px; color: #cfd3f2; backdrop-filter: blur(6px);
  animation: drift 8s ease-in-out infinite;
}
.chip-decline { top: 12%; left: 6%; animation-delay: -3s; }
.chip-allow { top: 24%; right: 4%; animation-delay: -6.5s; }
@keyframes drift { 50% { transform: translateY(-8px); } }
.dot { width: 6px; height: 6px; border-radius: 50%; flex: none; }
.dot-green { background: #a1edc1; box-shadow: 0 0 12px #76edaa94; }
.dot-red { background: #ff91a6; box-shadow: 0 0 12px #ff6b8a86; }

/* ---------- cards ---------- */
.statement .lead { max-width: 620px; }
.mode-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; margin-top: 36px; }
.mode-card, .step-list li {
  border: 1px solid var(--line); border-radius: 18px; padding: 24px; background: var(--surface);
  transition: transform .3s cubic-bezier(.2, .7, .3, 1), border-color .3s, box-shadow .3s;
}
.mode-card { background: linear-gradient(160deg, #14162366, #10121a); }
@media (hover: hover) {
  .mode-card:hover, .step-list li:hover {
    transform: translateY(-4px); border-color: #4a4f80;
    box-shadow: 0 18px 48px #00000066, 0 0 0 1px #4a4f8033;
  }
  .privacy-list li:hover { color: #f1f2fb; }
}
.icon-chip {
  width: 42px; height: 42px; border-radius: 13px; display: grid; place-items: center;
  border: 1px solid #33385c; background: #1c2036; color: var(--accent); margin-bottom: 16px;
}
.icon-chip svg { width: 21px; height: 21px; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }
.mode-card h3, .step-list h3 { font-size: 17px; letter-spacing: -.02em; margin-bottom: 9px; }
.mode-card p, .step-list p { color: var(--muted); font-size: 14px; line-height: 1.7; }
.note { margin-top: 22px; color: var(--muted); font-size: 13px; line-height: 1.6; }

/* ---------- steps ---------- */
.step-list { list-style: none; display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-top: 36px; }
.step-list li { position: relative; }
.step-num {
  display: inline-grid; place-items: center; width: 36px; height: 36px; margin-bottom: 15px;
  border-radius: 50%; border: 1px solid #44476b; background: linear-gradient(140deg, #232748, #191c31);
  color: var(--accent); font-size: 14px; font-weight: 700;
}
@media (min-width: 681px) {
  .step-list li:not(:last-child)::after {
    content: ""; position: absolute; top: 42px; left: calc(100% + 2px); width: 12px; height: 1px;
    border-top: 1px dashed #3a3e60;
  }
}

/* ---------- privacy ---------- */
.privacy-list { list-style: none; display: grid; gap: 2px; margin-top: 28px; max-width: 760px; }
.privacy-list li { padding: 17px 4px 17px 32px; position: relative; border-bottom: 1px solid var(--line); color: #c9cbe0; font-size: 15px; line-height: 1.65; transition: color .25s; }
.privacy-list li::before {
  content: ""; position: absolute; left: 3px; top: 25px; width: 11px; height: 6px;
  border-left: 2px solid var(--accent); border-bottom: 2px solid var(--accent);
  transform: rotate(-45deg);
}

/* ---------- cta ---------- */
.cta { text-align: center; position: relative; padding-bottom: clamp(80px, 12vw, 140px); }
.cta::before {
  content: ""; position: absolute; inset: auto 0 -30%; height: 80%; pointer-events: none;
  background: radial-gradient(ellipse 55% 70% at 50% 78%, #7c85f02e, transparent 70%);
}
.cta h2 { position: relative; margin-inline: auto; }

/* ---------- footer ---------- */
.footer { border-top: 1px solid var(--line); color: var(--muted); padding-block: 23px; font-size: 12px; }

/* ---------- reveal on scroll ---------- */
.js .reveal { opacity: 0; transform: translateY(22px); transition: opacity .7s ease, transform .7s cubic-bezier(.2, .7, .3, 1); }
.js .reveal.in { opacity: 1; transform: none; }
.mode-grid .reveal:nth-child(2) { transition-delay: .08s; }
.mode-grid .reveal:nth-child(3) { transition-delay: .16s; }
.mode-grid .reveal:nth-child(4) { transition-delay: .32s; }
.step-list .reveal:nth-child(2) { transition-delay: .1s; }
.step-list .reveal:nth-child(3) { transition-delay: .2s; }
.privacy-list .reveal:nth-child(2) { transition-delay: .08s; }

html { scroll-behavior: smooth; }
@media (max-width: 680px) {
  .nav, main, .footer { width: calc(100% - 36px); }
  .nav { height: 66px; }
  .nav-links { display: none; }
  .hero { grid-template-columns: 1fr; }
  .hero .orbit { max-width: 420px; margin-inline: auto; width: 100%; }
  .chip-decline { display: none; }
  .mode-grid, .step-list { grid-template-columns: 1fr; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; animation: none !important; }
  .js .reveal { opacity: 1; transform: none; }
  .sky { display: none; }
}