/* Sealboard — shared styles for landing / privacy / support */

:root {
  --accent: #d9f233;
  --accent-deep: #a6c71a;
  --bg: #07080a;
  --bg-elev: #11141a;
  --bg-card: #161a22;
  --text: #f4f6fa;
  --text-muted: #9aa3b2;
  --text-faint: #5d6677;
  --border: #21262f;
  --success: #4fd97c;
  --danger: #ff6b6b;
  --link: var(--accent);
  --radius: 14px;
  --content-max: 760px;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
               "PingFang SC", "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  font-size: 16px;
  line-height: 1.65;
  text-rendering: optimizeLegibility;
}

a { color: var(--link); text-decoration: none; transition: opacity .15s; }
a:hover { opacity: 0.8; }

/* Global container */
.container {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 0 24px;
}

/* Hero gradient at top of every page */
.hero-bg {
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(217, 242, 51, 0.12) 0%, transparent 65%);
  pointer-events: none;
  z-index: 0;
  filter: blur(40px);
}

/* Top nav */
.nav {
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  background: rgba(7, 8, 10, 0.75);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  gap: 18px;
}
.nav-brand {
  display: flex; align-items: center; gap: 10px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text);
  font-size: 17px;
}
.nav-brand .logo {
  width: 28px; height: 28px;
  border-radius: 7px;
  background: linear-gradient(135deg, var(--accent), var(--accent-deep));
  display: grid; place-items: center;
  box-shadow: 0 0 24px rgba(217, 242, 51, 0.4);
}
.nav-brand .logo svg { width: 16px; height: 16px; color: #07080a; }
.nav-links {
  margin-left: auto;
  display: flex;
  gap: 6px;
  align-items: center;
}
.nav-links a {
  color: var(--text-muted);
  padding: 6px 12px;
  border-radius: 8px;
  font-size: 14px;
  transition: background .15s, color .15s;
}
.nav-links a:hover { color: var(--text); background: var(--bg-elev); opacity: 1; }
.nav-links a.active { color: var(--accent); background: rgba(217, 242, 51, 0.08); }

.lang-toggle {
  display: inline-flex;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 3px;
  margin-left: 8px;
}
.lang-toggle button {
  background: none;
  border: none;
  color: var(--text-muted);
  padding: 4px 12px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: background .15s, color .15s;
}
.lang-toggle button.on {
  background: var(--accent);
  color: #07080a;
}

/* Page header */
.page-header {
  position: relative;
  padding: 80px 0 50px;
  text-align: center;
}
.page-header h1 {
  font-size: clamp(34px, 6vw, 52px);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 0 0 14px;
  background: linear-gradient(180deg, #fff, #9aa3b2);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.page-header .lede {
  font-size: 17px;
  color: var(--text-muted);
  max-width: 540px;
  margin: 0 auto;
}
.page-header .updated {
  display: inline-block;
  margin-top: 18px;
  padding: 5px 12px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: 12px;
  color: var(--text-muted);
}

/* Article body */
article {
  position: relative;
  padding: 24px 0 80px;
  z-index: 1;
}

article h2 {
  font-size: 22px;
  font-weight: 700;
  margin: 48px 0 14px;
  letter-spacing: -0.01em;
  display: flex;
  align-items: center;
  gap: 10px;
}
article h2::before {
  content: "";
  width: 4px;
  height: 22px;
  background: var(--accent);
  border-radius: 2px;
  flex-shrink: 0;
}
article h3 {
  font-size: 16px;
  font-weight: 600;
  margin: 28px 0 8px;
  color: var(--text);
}
article p,
article li {
  color: var(--text-muted);
  font-size: 15px;
  line-height: 1.75;
}
article p { margin: 0 0 14px; }
article ul, article ol { padding-left: 22px; margin: 0 0 18px; }
article li { margin-bottom: 6px; }
article strong { color: var(--text); font-weight: 600; }
article code {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 5px;
  padding: 2px 6px;
  font-size: 13px;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  color: var(--accent);
}

/* Hero feature cards on index */
.hero {
  position: relative;
  padding: 100px 0 60px;
  text-align: center;
  z-index: 1;
}
.hero h1 {
  font-size: clamp(48px, 9vw, 80px);
  font-weight: 800;
  margin: 0 0 18px;
  letter-spacing: -0.03em;
  background: linear-gradient(180deg, #fff 30%, #6b7587);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1.05;
}
.hero .tagline {
  font-size: 19px;
  color: var(--text-muted);
  max-width: 540px;
  margin: 0 auto 36px;
}
.hero .actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 22px;
  border-radius: 10px;
  font-size: 15px;
  font-weight: 600;
  transition: transform .12s, opacity .15s;
}
.btn:active { transform: scale(0.98); }
.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-deep));
  color: #07080a;
  box-shadow: 0 8px 24px rgba(217, 242, 51, 0.25);
}
.btn-secondary {
  background: var(--bg-elev);
  color: var(--text);
  border: 1px solid var(--border);
}

.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
  margin: 60px 0;
}
.feature {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px;
}
.feature .icon {
  width: 38px; height: 38px;
  border-radius: 9px;
  background: rgba(217, 242, 51, 0.12);
  display: grid; place-items: center;
  color: var(--accent);
  margin-bottom: 14px;
}
.feature .icon svg { width: 18px; height: 18px; }
.feature h3 {
  margin: 0 0 6px;
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
}
.feature p {
  margin: 0;
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.55;
}

/* FAQ-style cards */
.faq {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
}
.faq summary {
  cursor: pointer;
  padding: 16px 20px;
  font-weight: 600;
  font-size: 15px;
  color: var(--text);
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+";
  font-size: 20px;
  color: var(--text-faint);
  flex-shrink: 0;
  transition: transform .2s;
}
.faq[open] summary::after { transform: rotate(45deg); }
.faq[open] summary { color: var(--accent); }
.faq .answer {
  padding: 0 20px 18px;
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.7;
}
.faq .answer p { margin: 0 0 10px; }
.faq .answer p:last-child { margin-bottom: 0; }

/* Contact card */
.contact-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  margin-top: 24px;
}
.contact-card h3 { margin-top: 0; }
.contact-card a { font-weight: 600; }

/* Footer */
footer {
  border-top: 1px solid var(--border);
  padding: 32px 0;
  margin-top: 40px;
  text-align: center;
  position: relative;
  z-index: 1;
}
footer p {
  margin: 0;
  font-size: 13px;
  color: var(--text-faint);
}
footer .links {
  display: flex;
  gap: 18px;
  justify-content: center;
  margin-top: 12px;
}
footer .links a {
  color: var(--text-muted);
  font-size: 13px;
}

/* Language switching */
[data-lang] { display: none; }
html[lang="zh"] [data-lang="zh"],
html[lang="en"] [data-lang="en"] { display: block; }
html[lang="zh"] li[data-lang="zh"],
html[lang="en"] li[data-lang="en"] { display: list-item; }
html[lang="zh"] span[data-lang="zh"],
html[lang="en"] span[data-lang="en"] { display: inline; }

/* Mobile */
@media (max-width: 640px) {
  .nav-inner { padding: 12px 16px; }
  .nav-links { gap: 0; }
  .nav-links a { padding: 6px 8px; font-size: 13px; }
  .container { padding: 0 18px; }
  .hero { padding: 60px 0 40px; }
  .page-header { padding: 50px 0 30px; }
  .features { grid-template-columns: 1fr; }
}