:root,
[data-theme="light"] {
  color-scheme: light;
  --page-bg: #f4f5fa;
  --surface: #ffffff;
  --surface-soft: #eef2ff;
  --text: #1a1d24;
  --text-secondary: #5c6470;
  --border: rgba(26, 29, 36, 0.08);
  --accent: #4a78ff;
  --accent-strong: #3d66e8;
  --accent-soft: rgba(74, 120, 255, 0.12);
  --hero-gradient: linear-gradient(135deg, #4a78ff 0%, #6fa8ff 55%, #8ec5ff 100%);
  --shadow: 0 18px 48px rgba(74, 120, 255, 0.12);
  --code-bg: #f1f3f8;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --page-bg: #0f1116;
    --surface: #171a21;
    --surface-soft: #1a2438;
    --text: #eef1f6;
    --text-secondary: #a8b0bd;
    --border: rgba(255, 255, 255, 0.08);
    --accent: #6fa8ff;
    --accent-strong: #8ec0ff;
    --accent-soft: rgba(111, 168, 255, 0.14);
    --hero-gradient: linear-gradient(135deg, #243b88 0%, #3558c7 55%, #4a78ff 100%);
    --shadow: 0 18px 48px rgba(0, 0, 0, 0.35);
    --code-bg: #22262f;
  }
}

[data-theme="dark"] {
  color-scheme: dark;
  --page-bg: #0f1116;
  --surface: #171a21;
  --surface-soft: #1a2438;
  --text: #eef1f6;
  --text-secondary: #a8b0bd;
  --border: rgba(255, 255, 255, 0.08);
  --accent: #6fa8ff;
  --accent-strong: #8ec0ff;
  --accent-soft: rgba(111, 168, 255, 0.14);
  --hero-gradient: linear-gradient(135deg, #243b88 0%, #3558c7 55%, #4a78ff 100%);
  --shadow: 0 18px 48px rgba(0, 0, 0, 0.35);
  --code-bg: #22262f;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--page-bg);
  color: var(--text);
  line-height: 1.6;
}

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

a:hover {
  color: var(--accent-strong);
  text-decoration: underline;
}

img {
  max-width: 100%;
}

.container {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(14px);
  background: color-mix(in srgb, var(--page-bg) 82%, transparent);
  border-bottom: 1px solid var(--border);
}

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

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 700;
  font-size: 18px;
  text-decoration: none;
}

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

.brand-mark {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 14px;
  font-weight: 800;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 18px;
}

.nav-links a {
  color: var(--text-secondary);
  font-size: 14px;
  text-decoration: none;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--accent);
  text-decoration: none;
}

.theme-switch {
  display: inline-flex;
  padding: 3px;
  border-radius: 999px;
  background: var(--surface);
  border: 1px solid var(--border);
}

.theme-switch button {
  border: 0;
  background: transparent;
  color: var(--text-secondary);
  font-size: 12px;
  padding: 6px 10px;
  border-radius: 999px;
  cursor: pointer;
}

.theme-switch button.active {
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 600;
}

.hero {
  padding: 72px 0 48px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 40px;
  align-items: center;
}

.hero-copy h1 {
  margin: 0 0 16px;
  font-size: clamp(36px, 5vw, 56px);
  line-height: 1.08;
  letter-spacing: -0.03em;
}

.hero-copy p {
  margin: 0 0 28px;
  font-size: 18px;
  color: var(--text-secondary);
  max-width: 560px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 12px;
  font-size: 15px;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
}

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

.btn-primary {
  background: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-strong);
  color: #fff;
}

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

.btn-secondary:hover {
  color: var(--text);
  border-color: color-mix(in srgb, var(--accent) 35%, var(--border));
}

.hero-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 28px;
  box-shadow: var(--shadow);
}

.hero-card-top {
  height: 220px;
  border-radius: 18px;
  background: var(--hero-gradient);
  display: grid;
  place-items: center;
  color: #fff;
  font-size: 28px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.hero-card-meta {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-top: 18px;
}

.stat {
  padding: 14px;
  border-radius: 14px;
  background: var(--surface-soft);
}

.stat strong {
  display: block;
  font-size: 18px;
  margin-bottom: 4px;
}

.stat span {
  font-size: 12px;
  color: var(--text-secondary);
}

.section {
  padding: 28px 0 56px;
}

.section-title {
  margin: 0 0 10px;
  font-size: 28px;
}

.section-desc {
  margin: 0 0 24px;
  color: var(--text-secondary);
}

.feature-grid,
.download-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.feature-card,
.download-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 22px;
}

.feature-card h3,
.download-card h3 {
  margin: 0 0 8px;
  font-size: 18px;
}

.feature-card p,
.download-card p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 14px;
}

.page-main {
  padding: 40px 0 64px;
}

.doc-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 32px;
  box-shadow: var(--shadow);
}

.doc-card h1 {
  margin: 0 0 8px;
  font-size: clamp(28px, 4vw, 36px);
}

.doc-meta {
  margin: 0 0 28px;
  color: var(--text-secondary);
  font-size: 14px;
}

.doc-card h2 {
  margin: 28px 0 10px;
  font-size: 20px;
}

.doc-card h3 {
  margin: 20px 0 8px;
  font-size: 16px;
}

.doc-card p,
.doc-card li {
  color: var(--text-secondary);
}

.doc-card ul,
.doc-card ol {
  padding-left: 1.25rem;
}

.doc-card table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 14px;
}

.doc-card th,
.doc-card td {
  border: 1px solid var(--border);
  padding: 10px 12px;
  text-align: left;
  vertical-align: top;
}

.doc-card th {
  background: var(--surface-soft);
  color: var(--text);
}

.doc-card code {
  background: var(--code-bg);
  padding: 2px 6px;
  border-radius: 6px;
  font-size: 0.92em;
}

.legal-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 18px;
  margin-top: 24px;
}

.site-footer {
  border-top: 1px solid var(--border);
  padding: 28px 0 40px;
  color: var(--text-secondary);
  font-size: 13px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 24px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 16px;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
}

.footer-links a:hover {
  color: var(--accent);
}

@media (max-width: 900px) {
  .hero-grid,
  .feature-grid,
  .download-grid,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .nav-links {
    display: none;
  }

  .hero {
    padding-top: 40px;
  }
}

@media (max-width: 640px) {
  .theme-switch button {
    padding: 6px 8px;
    font-size: 11px;
  }

  .doc-card {
    padding: 22px 18px;
  }

  .doc-card table {
    display: block;
    overflow-x: auto;
  }
}