:root {
  color-scheme: light dark;
  --bg: #f8fafc;
  --bg-subtle: #f1f5f9;
  --surface: #ffffff;
  --surface-alt: #f8fafc;
  --border: #e2e8f0;
  --border-strong: #cbd5e1;
  --text: #0f172a;
  --text-secondary: #334155;
  --text-muted: #475569;
  --brand: #0057eb;
  --brand-hover: #0046c2;
  --brand-soft: #eff6ff;
  --brand-border: #bfdbfe;
  --brand-text: #1d4ed8;
  --beta-bg: #fffbeb;
  --beta-border: #fcd34d;
  --beta-text: #92400e;
  --stable-bg: #ecfdf5;
  --stable-border: #6ee7b7;
  --stable-text: #065f46;
  --code-bg: #0f172a;
  --code-text: #f8fafc;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.05);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b1120;
    --bg-subtle: #111827;
    --surface: #131c2e;
    --surface-alt: #0f172a;
    --border: #1e293b;
    --border-strong: #334155;
    --text: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    --brand: #3b82f6;
    --brand-hover: #60a5fa;
    --brand-soft: rgba(59, 130, 246, 0.14);
    --brand-border: rgba(96, 165, 250, 0.36);
    --brand-text: #93c5fd;
    --beta-bg: rgba(245, 158, 11, 0.14);
    --beta-border: rgba(251, 191, 36, 0.42);
    --beta-text: #fde68a;
    --stable-bg: rgba(16, 185, 129, 0.14);
    --stable-border: rgba(52, 211, 153, 0.4);
    --stable-text: #6ee7b7;
    --code-bg: #090e1a;
    --code-text: #e2e8f0;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.35);
  }
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  font-size: 16px;
  line-height: 1.65;
}

a {
  color: var(--brand-text);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--brand);
  outline-offset: 2px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 8px;
  z-index: 100;
  padding: 8px 14px;
  border-radius: 8px;
  background: var(--brand);
  color: #ffffff;
  font-weight: 600;
}

.skip-link:focus {
  left: 12px;
}

.container {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 64px;
  padding-top: 8px;
  padding-bottom: 8px;
  flex-wrap: wrap;
}

.brand-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.brand-link:hover {
  text-decoration: none;
}

.brand-logo {
  display: block;
  height: 32px;
  width: auto;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

.nav-links a {
  display: inline-flex;
  align-items: center;
  padding: 6px 11px;
  border-radius: 8px;
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 500;
  text-decoration: none;
  transition: background-color 0.15s ease, color 0.15s ease;
}

.nav-links a:hover {
  background: var(--bg-subtle);
  color: var(--text);
  text-decoration: none;
}

.nav-links a.lang-switch {
  border: 1px solid var(--border-strong);
  color: var(--text);
  font-weight: 600;
}

/* Hero */
.hero {
  padding: 56px 0 40px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, var(--surface) 0%, var(--bg) 100%);
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 4px 12px;
  border-radius: 999px;
  background: var(--brand-soft);
  border: 1px solid var(--brand-border);
  color: var(--brand-text);
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 18px;
}

.hero h1 {
  margin: 0 0 16px;
  font-size: clamp(28px, 4.2vw, 44px);
  line-height: 1.2;
  letter-spacing: -0.02em;
  max-width: 880px;
}

.hero-lead {
  margin: 0 0 12px;
  font-size: clamp(17px, 2vw, 20px);
  color: var(--text-secondary);
  max-width: 820px;
}

.hero-sub {
  margin: 0 0 28px;
  font-size: 15px;
  color: var(--text-muted);
  max-width: 800px;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 42px;
  padding: 9px 18px;
  border-radius: 9px;
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid transparent;
  transition: background-color 0.15s ease, border-color 0.15s ease;
}

.btn:hover {
  text-decoration: none;
}

.btn-primary {
  background: #0057eb;
  color: #ffffff;
  border-color: #0057eb;
}

.btn-primary:hover {
  background: #0046c2;
  border-color: #0046c2;
  color: #ffffff;
}

.btn-secondary {
  background: var(--surface);
  color: var(--text);
  border-color: var(--border-strong);
}

.btn-secondary:hover {
  background: var(--bg-subtle);
}

/* Release Channels */
.section {
  padding: 44px 0;
}

.section + .section {
  border-top: 1px solid var(--border);
}

.section-header {
  margin-bottom: 24px;
}

.section-header h2 {
  margin: 0 0 8px;
  font-size: 24px;
  line-height: 1.3;
  letter-spacing: -0.01em;
}

.section-header p {
  margin: 0;
  color: var(--text-muted);
  font-size: 15px;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 22px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.card h3 {
  margin: 0;
  font-size: 18px;
  line-height: 1.35;
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.card p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 15px;
}

.card ul {
  margin: 0;
  padding-left: 18px;
  color: var(--text-secondary);
  font-size: 14.5px;
  display: grid;
  gap: 6px;
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 2px 9px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.badge-stable {
  background: var(--stable-bg);
  border: 1px solid var(--stable-border);
  color: var(--stable-text);
}

.badge-beta {
  background: var(--beta-bg);
  border: 1px solid var(--beta-border);
  color: var(--beta-text);
}

.code-block {
  margin: 4px 0 0;
  padding: 12px 14px;
  border-radius: 8px;
  background: var(--code-bg);
  color: var(--code-text);
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 13px;
  line-height: 1.55;
  overflow-x: auto;
  border: 1px solid var(--border-strong);
}

.card-links {
  margin-top: auto;
  padding-top: 8px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 16px;
  font-size: 14px;
  font-weight: 600;
}

.note-box {
  margin-top: 20px;
  padding: 14px 18px;
  border-radius: 10px;
  background: var(--surface-alt);
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 14px;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--surface);
  padding: 28px 0 36px;
  color: var(--text-muted);
  font-size: 14px;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 20px;
}

.not-found-main {
  min-height: calc(100vh - 160px);
  display: flex;
  align-items: center;
  padding: 64px 0;
}

@media (max-width: 860px) {
  .grid-2,
  .grid-3 {
    grid-template-columns: 1fr;
  }

  .hero {
    padding: 36px 0 28px;
  }

  .section {
    padding: 32px 0;
  }
}