:root {
  color-scheme: dark;
  --ink: #eaf8ff;
  --muted: #a9cadb;
  --line: rgba(74, 220, 240, .28);
  --cyan: #45dfee;
  --gold: #ffbd43;
  --panel: rgba(7, 23, 45, .82);
  --bg: #020915;
}

* { box-sizing: border-box; }
html { background: var(--bg); scroll-behavior: smooth; }
body {
  min-width: 320px;
  margin: 0;
  color: var(--ink);
  font: 16px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background:
    radial-gradient(circle at 10% 0%, rgba(25, 157, 198, .20), transparent 28rem),
    radial-gradient(circle at 90% 85%, rgba(0, 203, 232, .13), transparent 28rem),
    linear-gradient(135deg, #07142a 0%, #020814 55%, #071a2c 100%);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: .28;
  background-image: linear-gradient(rgba(75, 215, 235, .10) 1px, transparent 1px), linear-gradient(90deg, rgba(75, 215, 235, .10) 1px, transparent 1px);
  background-size: 54px 54px;
  mask-image: linear-gradient(to bottom, black, transparent 75%);
}

a { color: #8cf3ff; text-underline-offset: 3px; }
.shell { width: min(920px, calc(100% - 40px)); margin: 0 auto; position: relative; }
header { padding: 28px 0 17px; border-bottom: 1px solid var(--line); }
.topbar { display: flex; align-items: center; justify-content: space-between; gap: 18px; }
.brand { color: var(--ink); text-decoration: none; display: inline-flex; align-items: center; gap: 10px; font-weight: 800; letter-spacing: .08em; }
.mark { width: 27px; height: 27px; display: inline-grid; place-items: center; border: 1px solid var(--cyan); border-radius: 7px; color: var(--cyan); font-size: 13px; box-shadow: 0 0 18px rgba(45, 219, 239, .28); }
nav { display: flex; align-items: center; gap: 17px; font-size: 14px; }
nav a { text-decoration: none; color: var(--muted); }
nav a:hover, nav a[aria-current="page"] { color: var(--cyan); }

main { padding: 58px 0 52px; }
.eyebrow { margin: 0 0 9px; color: var(--cyan); font-size: 13px; font-weight: 800; letter-spacing: .13em; text-transform: uppercase; }
h1, h2, h3 { line-height: 1.2; }
h1 { max-width: 740px; margin: 0; font-size: clamp(36px, 6vw, 64px); letter-spacing: -.04em; }
.lede { max-width: 660px; margin: 20px 0 0; color: var(--muted); font-size: 19px; }
.hero { padding-bottom: 42px; }
.cards { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.card, .article { border: 1px solid var(--line); border-radius: 19px; background: var(--panel); box-shadow: 0 20px 48px rgba(0, 0, 0, .20); backdrop-filter: blur(10px); }
.card { padding: 25px; }
.card h2 { margin: 0 0 9px; font-size: 21px; }
.card p { color: var(--muted); margin: 0; }
.button { display: inline-block; margin-top: 18px; padding: 10px 17px; border: 1px solid rgba(70, 228, 239, .55); border-radius: 10px; color: #00141d; font-weight: 750; text-decoration: none; background: linear-gradient(135deg, #8df4ff, #39c2d7); }
.article { padding: clamp(25px, 5vw, 54px); }
.article h2 { margin: 40px 0 12px; color: var(--gold); font-size: 22px; }
.article h2:first-of-type { margin-top: 18px; }
.article p, .article li { color: var(--muted); }
.article strong { color: var(--ink); }
.article ul { padding-left: 23px; }
.note { padding: 14px 17px; border-left: 3px solid var(--cyan); border-radius: 7px; color: var(--muted); background: rgba(31, 117, 148, .14); }
.contact { margin-top: 25px; padding: 24px; border-radius: 14px; background: rgba(7, 63, 91, .38); }
.contact h2 { margin-top: 0; }
.zh { display: none; }
html:lang(zh-CN) .en { display: none; }
html:lang(zh-CN) .zh { display: block; }
footer { padding: 25px 0 36px; border-top: 1px solid var(--line); color: #80a7ba; font-size: 13px; }
footer .shell { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 9px 20px; }

@media (max-width: 620px) {
  .shell { width: min(100% - 30px, 920px); }
  header { padding-top: 18px; }
  .topbar { align-items: flex-start; flex-direction: column; gap: 11px; }
  main { padding-top: 39px; }
  .cards { grid-template-columns: 1fr; }
  .article { padding: 23px; }
}