@font-face {
  font-family: "Space Grotesk";
  src: url("fonts/SpaceGrotesk-Variable.ttf") format("truetype");
  font-weight: 300 700;
  font-display: swap;
}

:root {
  --page: #1c1c28;
  --card: rgb(48, 48, 60);
  --inner: rgb(68, 68, 80);
  --blue: #00b5fe;
  --ink: #ffffff;
  --secondary: rgba(255, 255, 255, 0.55);
  --line: rgba(255, 255, 255, 0.14);
  --font: "Space Grotesk", -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--page);
  color: var(--ink);
  font: 16px/1.7 var(--font);
  -webkit-font-smoothing: antialiased;
}

a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }

/* One language at a time (set on <html> by lang.js; English without script). */
html[data-lang="en"] .zh, html[data-lang="zh"] .en { display: none !important; }

.wrap { max-width: 720px; margin: 0 auto; padding: 0 20px; }

/* Top bar */
.bar {
  position: sticky; top: 0; z-index: 5;
  background: rgba(28, 28, 40, 0.82);
  backdrop-filter: saturate(160%) blur(16px);
  -webkit-backdrop-filter: saturate(160%) blur(16px);
  border-bottom: 0.5px solid var(--line);
}
.bar .wrap { display: flex; align-items: center; gap: 12px; height: 56px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); font-weight: 600; font-size: 17px; }
.brand:hover { text-decoration: none; }
.brand img { width: 30px; height: 30px; border-radius: 8px; }
.bar nav { margin-left: auto; display: flex; align-items: center; gap: 4px; }
.bar nav a { color: var(--secondary); font-size: 15px; padding: 8px 10px; border-radius: 12px; }
.bar nav a:hover { color: var(--ink); text-decoration: none; }
.lang {
  font: inherit; font-size: 14px; color: var(--ink);
  background: var(--card); border: 0; border-radius: 999px;
  padding: 6px 14px; margin-left: 6px; cursor: pointer;
}

/* Landing */
.hero { text-align: center; padding: 64px 0 40px; }
.hero .icon {
  width: 128px; height: 128px; border-radius: 30%;
  box-shadow: 0 18px 50px rgba(0, 181, 254, 0.25), 0 6px 18px rgba(0, 0, 0, 0.4);
}
.hero h1 { font-size: 44px; line-height: 1.15; margin: 28px 0 10px; letter-spacing: -0.01em; }
.hero .tagline { font-size: 20px; color: var(--secondary); margin: 0; }
.soon {
  display: inline-block; margin-top: 28px; padding: 12px 24px;
  border-radius: 999px; background: var(--blue); color: #fff; font-weight: 600;
}

.faces { display: flex; justify-content: center; gap: 12px; flex-wrap: wrap; margin: 8px 0 48px; }
.faces img { width: 56px; height: 56px; border-radius: 30%; opacity: 0.95; }

.cards { display: grid; gap: 16px; grid-template-columns: 1fr; margin-bottom: 40px; }
@media (min-width: 640px) { .cards { grid-template-columns: repeat(3, 1fr); } }
.card { background: var(--card); border-radius: 24px; padding: 24px 20px; }
.card .em { font-size: 34px; line-height: 1; }
.card h3 { font-size: 18px; margin: 14px 0 6px; }
.card p { margin: 0; color: var(--secondary); font-size: 15px; line-height: 1.6; }

.note {
  background: var(--card); border-radius: 24px; padding: 20px;
  display: flex; gap: 16px; align-items: center; margin-bottom: 56px;
}
.note img { width: 52px; height: 52px; border-radius: 30%; flex: none; }
.note p { margin: 0; color: var(--secondary); font-size: 15px; }
.note b { color: var(--ink); }

/* Text pages */
.doc { padding-top: 40px; padding-bottom: 56px; }
.doc h1 { font-size: 32px; line-height: 1.2; margin: 0 0 6px; }
.doc .date { color: var(--secondary); font-size: 14px; margin: 0 0 28px; }
.doc h2 { font-size: 19px; margin: 32px 0 6px; }
.doc p, .doc li { color: rgba(255, 255, 255, 0.82); }
.doc ul { padding-left: 20px; }

.contact {
  background: var(--card); border-radius: 24px; padding: 24px 20px; margin: 8px 0 8px;
  display: flex; gap: 16px; align-items: center;
}
.contact img { width: 56px; height: 56px; border-radius: 30%; flex: none; }
.contact .mail { font-size: 20px; font-weight: 600; }
.contact p { margin: 2px 0 0; color: var(--secondary); font-size: 15px; }

.qa { background: var(--card); border-radius: 24px; padding: 4px 20px; margin-top: 16px; }
.qa details { border-bottom: 0.5px solid var(--line); }
.qa details:last-child { border-bottom: 0; }
.qa summary { cursor: pointer; padding: 14px 0; font-weight: 600; list-style: none; }
.qa summary::-webkit-details-marker { display: none; }
.qa summary::after { content: "+"; float: right; color: var(--secondary); font-weight: 400; }
.qa details[open] summary::after { content: "–"; }
.qa details p { margin: 0 0 14px; color: var(--secondary); font-size: 15px; }

footer { border-top: 0.5px solid var(--line); padding: 24px 0 40px; color: var(--secondary); font-size: 14px; }
footer .wrap { display: flex; flex-wrap: wrap; gap: 8px 20px; }
footer a { color: var(--secondary); }

@media (max-width: 480px) {
  .hero { padding-top: 44px; }
  .hero h1 { font-size: 36px; }
  .hero .tagline { font-size: 18px; }
  .bar nav a { padding: 8px 6px; font-size: 14px; }
  .faces { gap: 8px; }
  .faces img { width: 40px; height: 40px; }
}