:root {
  --bg: #f0f4ff;
  --surface: #ffffff;
  --text: #0f172a;
  --muted: #64748b;
  --primary: #1d4ed8;
  --primary-hover: #1e40af;
  --border: #e2e8f0;
  --radius: 12px;
  --shadow: 0 12px 40px rgba(15, 23, 42, 0.08);
  --max: 1080px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: 'Segoe UI', system-ui, -apple-system, 'PingFang SC', 'Microsoft YaHei',
    sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
}

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

a:hover {
  text-decoration: underline;
}

.skip {
  position: absolute;
  left: -9999px;
  top: auto;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

.skip:focus {
  position: fixed;
  left: 16px;
  top: 16px;
  width: auto;
  height: auto;
  padding: 8px 12px;
  background: var(--surface);
  z-index: 1000;
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--text);
  text-decoration: none;
}

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

.brand-mark {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--primary), #6366f1);
  display: grid;
  place-items: center;
  color: #fff;
  font-size: 14px;
  font-weight: 800;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  align-items: center;
}

.nav a {
  color: var(--muted);
  font-size: 0.9375rem;
  text-decoration: none;
}

.nav a:hover {
  color: var(--primary);
  text-decoration: none;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.9375rem;
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.15s, transform 0.1s;
}

.btn:active {
  transform: scale(0.98);
}

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

.btn-primary:hover {
  background: var(--primary-hover);
  color: #fff;
  text-decoration: none;
}

.btn-outline {
  background: var(--surface);
  color: var(--primary);
  border: 1px solid var(--border);
}

.btn-outline:hover {
  border-color: var(--primary);
  text-decoration: none;
}

.is-disabled {
  opacity: 0.45;
  pointer-events: none;
  cursor: not-allowed;
}

main {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 20px 64px;
}

.hero {
  padding: 56px 0 40px;
  display: grid;
  gap: 28px;
  grid-template-columns: 1fr;
  align-items: center;
}

@media (min-width: 880px) {
  .hero {
    grid-template-columns: 1.1fr 0.9fr;
    padding: 72px 0 48px;
  }
}

.hero h1 {
  margin: 0 0 12px;
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.lead {
  margin: 0 0 24px;
  font-size: 1.0625rem;
  color: var(--muted);
  max-width: 36em;
}

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

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

.hero-card h2 {
  margin: 0 0 8px;
  font-size: 1rem;
  color: var(--muted);
  font-weight: 600;
}

.hero-card ul {
  margin: 0;
  padding-left: 1.1em;
  color: var(--text);
}

.section {
  padding: 40px 0;
}

.section h2 {
  margin: 0 0 8px;
  font-size: 1.5rem;
}

.section > p.sub {
  margin: 0 0 28px;
  color: var(--muted);
}

.grid {
  display: grid;
  gap: 16px;
  grid-template-columns: 1fr;
}

@media (min-width: 640px) {
  .grid-2 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 900px) {
  .grid-3 {
    grid-template-columns: repeat(3, 1fr);
  }
}

.card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 22px;
  border: 1px solid var(--border);
  box-shadow: 0 4px 20px rgba(15, 23, 42, 0.04);
}

.card h3 {
  margin: 0 0 8px;
  font-size: 1.0625rem;
}

.card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.9375rem;
}

.download-grid {
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
}

.download-grid a {
  text-decoration: none;
}

.download-tile {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  transition: border-color 0.15s, box-shadow 0.15s;
}

.download-tile:hover {
  border-color: var(--primary);
  box-shadow: 0 8px 24px rgba(29, 78, 216, 0.12);
  text-decoration: none;
}

.download-tile strong {
  display: block;
  font-size: 0.9375rem;
}

.download-tile span {
  font-size: 0.8125rem;
  color: var(--muted);
}

.dl-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--bg);
  display: grid;
  place-items: center;
  font-size: 1.25rem;
}

.dl-icon--compact {
  font-size: 0.7rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.note {
  margin-top: 20px;
  padding: 14px 16px;
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  border-radius: var(--radius);
  font-size: 0.875rem;
  color: #1e3a8a;
}

.site-footer {
  border-top: 1px solid var(--border);
  background: var(--surface);
  padding: 32px 20px 40px;
  margin-top: 24px;
}

.footer-inner {
  max-width: var(--max);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
  font-size: 0.875rem;
  color: var(--muted);
}

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

.legal-page {
  max-width: 720px;
  margin: 0 auto;
  padding: 40px 20px 64px;
}

.legal-page h1 {
  margin-top: 0;
  font-size: 1.75rem;
}

.legal-page .legal-subtitle {
  margin: -8px 0 16px;
  color: var(--muted);
  font-size: 0.9375rem;
}

.legal-page h2 {
  margin-top: 28px;
  font-size: 1.125rem;
}

.legal-page h3 {
  margin-top: 18px;
  margin-bottom: 8px;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
}

.legal-page p,
.legal-page li {
  color: var(--muted);
  font-size: 0.9375rem;
}

.legal-page ul {
  padding-left: 1.25rem;
}

.legal-page .legal-meta {
  margin-bottom: 24px;
  color: var(--muted);
  font-size: 0.9375rem;
  line-height: 1.7;
}

.legal-page .legal-callout {
  padding: 12px 14px;
  margin: 0 0 20px;
  background: #fffbeb;
  border: 1px solid #fde68a;
  border-radius: var(--radius);
  color: #78350f;
  font-size: 0.9375rem;
  line-height: 1.55;
}

.legal-page .legal-signoff {
  margin-top: 28px;
  color: var(--text);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.legal-table-wrap {
  overflow-x: auto;
  margin: 12px 0 20px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.legal-table {
  width: 100%;
  min-width: 420px;
  border-collapse: collapse;
  font-size: 0.875rem;
}

.legal-table th,
.legal-table td {
  padding: 10px 12px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--border);
  color: var(--muted);
}

.legal-table th {
  background: var(--bg);
  color: var(--text);
  font-weight: 600;
}

.legal-table tbody tr:last-child th,
.legal-table tbody tr:last-child td {
  border-bottom: none;
}

.legal-note {
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.55;
  margin-top: 8px;
}