/* Shared styles for the public marketing / policy site (bilingual zh/en). */
:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --text: #1f2937;
  --text-light: #6b7280;
  --bg: #ffffff;
  --bg-soft: #f8fafc;
  --border: #e5e7eb;
  --max-width: 1080px;
  --doc-width: 820px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.75;
}

/* ---- Language visibility ---- */
html[data-lang="en"] .zh { display: none !important; }
html[data-lang="zh"] .en { display: none !important; }

/* ---- Header ---- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.site-header .inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.brand {
  font-size: 20px;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 10px;
}
.brand .logo-dot {
  width: 28px;
  height: 28px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--primary), #7c3aed);
  display: inline-block;
}
.site-nav { display: flex; align-items: center; gap: 22px; }
.site-nav a {
  color: var(--text-light);
  text-decoration: none;
  font-size: 14px;
}
.site-nav a:hover { color: var(--primary); }
.lang-btn {
  border: 1px solid var(--border);
  background: var(--bg);
  border-radius: 6px;
  padding: 5px 14px;
  font-size: 13px;
  cursor: pointer;
  color: var(--text);
}
.lang-btn:hover { border-color: var(--primary); color: var(--primary); }

/* ---- Hero ---- */
.hero {
  background: linear-gradient(180deg, #eff6ff 0%, #ffffff 100%);
  padding: 88px 24px 72px;
  text-align: center;
}
.hero h1 {
  font-size: 42px;
  line-height: 1.25;
  margin: 0 auto 18px;
  max-width: 820px;
  letter-spacing: -0.02em;
}
.hero p.sub {
  font-size: 18px;
  color: var(--text-light);
  max-width: 720px;
  margin: 0 auto 34px;
}
.btn-primary {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  padding: 12px 32px;
  border-radius: 8px;
  text-decoration: none;
  font-size: 16px;
  font-weight: 600;
}
.btn-primary:hover { background: var(--primary-dark); }

/* ---- Sections ---- */
.section { padding: 72px 24px; }
.section.alt { background: var(--bg-soft); }
.section .inner { max-width: var(--max-width); margin: 0 auto; }
.section h2 {
  font-size: 30px;
  text-align: center;
  margin: 0 0 12px;
  letter-spacing: -0.01em;
}
.section p.lead {
  text-align: center;
  color: var(--text-light);
  max-width: 720px;
  margin: 0 auto 48px;
  font-size: 16px;
}
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}
.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px;
}
.card .icon { font-size: 28px; margin-bottom: 12px; }
.card h3 { margin: 0 0 8px; font-size: 18px; }
.card p { margin: 0; color: var(--text-light); font-size: 14.5px; }

/* ---- Steps ---- */
.steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 24px; counter-reset: step; }
.step { text-align: center; padding: 0 12px; }
.step .num {
  width: 44px; height: 44px; border-radius: 50%;
  background: var(--primary); color: #fff;
  display: inline-flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 18px; margin-bottom: 14px;
}
.step h3 { margin: 0 0 6px; font-size: 17px; }
.step p { margin: 0; color: var(--text-light); font-size: 14.5px; }

/* ---- Document pages (privacy / terms / data deletion) ---- */
.doc {
  max-width: var(--doc-width);
  margin: 0 auto;
  padding: 48px 24px 80px;
}
.doc h1 { font-size: 30px; margin: 0 0 6px; letter-spacing: -0.01em; }
.doc .meta { color: var(--text-light); font-size: 14px; margin-bottom: 32px; }
.doc h2 { font-size: 20px; margin: 34px 0 10px; }
.doc h3 { font-size: 16.5px; margin: 22px 0 8px; }
.doc p, .doc li { font-size: 15px; margin: 8px 0; }
.doc ul, .doc ol { padding-left: 24px; }
.doc a { color: var(--primary); }
.doc .notice {
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  border-radius: 8px;
  padding: 14px 18px;
  font-size: 14.5px;
}
.doc table { border-collapse: collapse; width: 100%; font-size: 14px; }
.doc table th, .doc table td { border: 1px solid var(--border); padding: 8px 12px; text-align: left; }
.doc table th { background: var(--bg-soft); }

/* ---- Footer ---- */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--bg-soft);
  padding: 40px 24px;
  font-size: 14px;
  color: var(--text-light);
}
.site-footer .inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  gap: 16px 40px;
  justify-content: space-between;
  align-items: center;
}
.site-footer a { color: var(--text-light); text-decoration: none; margin-right: 20px; }
.site-footer a:hover { color: var(--primary); }

@media (max-width: 640px) {
  .hero h1 { font-size: 30px; }
  .site-nav a.nav-doc { display: none; }
}