:root {
  color-scheme: dark;
  --surface: #07111f;
  --elevated: #0d1b2e;
  --text: #f3f8ff;
  --muted: #9fb2c9;
  --accent: #65c8ff;
  --accent-contrast: #03121f;
  --border: rgba(166, 207, 239, 0.2);
  --success: #76e2b3;
  --radius: 22px;
  --display: ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --body: ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { background: var(--surface); scroll-behavior: smooth; }
body { margin: 0; color: var(--text); background: radial-gradient(circle at 50% -20%, #153457 0, var(--surface) 42rem); font-family: var(--body); line-height: 1.65; }
a { color: var(--accent); }
a:focus-visible, button:focus-visible { outline: 3px solid var(--accent); outline-offset: 4px; }
.shell { width: min(1060px, calc(100% - 32px)); margin: 0 auto; }
header { display: flex; align-items: center; justify-content: space-between; gap: 24px; padding: 24px 0; border-bottom: 1px solid var(--border); }
.brand { display: inline-flex; align-items: center; gap: 12px; color: var(--text); text-decoration: none; font-weight: 760; letter-spacing: -0.02em; }
.mark { width: 42px; height: 42px; display: grid; place-items: center; border-radius: 13px; background: linear-gradient(145deg, #4cbcff, #9be4ff); color: var(--accent-contrast); box-shadow: 0 16px 40px rgba(66, 181, 255, 0.22); }
nav { display: flex; flex-wrap: wrap; gap: 8px 18px; }
nav a { color: var(--muted); text-decoration: none; font-size: 0.94rem; }
nav a:hover { color: var(--text); }
main { padding: 76px 0 84px; }
.hero { max-width: 780px; margin: 0 auto 56px; text-align: center; }
.eyebrow { color: var(--accent); font-size: 0.78rem; font-weight: 760; letter-spacing: 0.13em; text-transform: uppercase; }
h1, h2, h3 { font-family: var(--display); line-height: 1.12; letter-spacing: -0.035em; }
h1 { margin: 18px 0; font-size: clamp(2.6rem, 8vw, 5.5rem); }
h2 { margin-top: 0; font-size: clamp(1.75rem, 4vw, 2.65rem); }
h3 { font-size: 1.15rem; }
.lead { color: var(--muted); font-size: clamp(1.05rem, 2.3vw, 1.28rem); }
.pills { display: flex; justify-content: center; flex-wrap: wrap; gap: 10px; margin-top: 28px; }
.pill { padding: 8px 13px; border: 1px solid var(--border); border-radius: 999px; color: var(--muted); background: rgba(255,255,255,0.025); }
.grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; margin: 36px 0 60px; }
.card, .document { background: linear-gradient(180deg, rgba(255,255,255,0.055), rgba(255,255,255,0.025)); border: 1px solid var(--border); border-radius: var(--radius); padding: 26px; }
.card p, .document p, .document li { color: var(--muted); }
.document { max-width: 860px; margin: 0 auto; }
.document section + section { margin-top: 38px; padding-top: 30px; border-top: 1px solid var(--border); }
.callout { border-left: 4px solid var(--success); padding: 14px 18px; background: rgba(118,226,179,0.08); border-radius: 0 14px 14px 0; }
footer { border-top: 1px solid var(--border); padding: 28px 0 42px; color: var(--muted); font-size: 0.88rem; }
footer .shell { display: flex; justify-content: space-between; gap: 20px; flex-wrap: wrap; }
.zh { margin-top: 28px; padding-top: 24px; border-top: 1px dashed var(--border); }

@media (max-width: 760px) {
  header { align-items: flex-start; flex-direction: column; }
  main { padding-top: 54px; }
  .grid { grid-template-columns: 1fr; }
  .card, .document { padding: 22px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}