:root {
  color-scheme: light dark;
  --bg: #f5f6f8;
  --fg: #1a1d22;
  --muted: #5a6370;
  --card: #ffffff;
  --border: #e2e5ea;
  --accent: #2a6df4;
  --accent-fg: #ffffff;
  --footer-bg: #1a1d22;
  --footer-fg: #cfd3da;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1217;
    --fg: #e8eaed;
    --muted: #9aa0a6;
    --card: #181c22;
    --border: #2a2f37;
    --accent: #4d8bff;
    --accent-fg: #0f1217;
    --footer-bg: #0a0c10;
    --footer-fg: #9aa0a6;
  }
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.page {
  flex: 1;
  max-width: 880px;
  width: 100%;
  margin: 0 auto;
  padding: 64px 24px 48px;
}

.hero {
  text-align: center;
  margin-bottom: 48px;
}

.hero-logo {
  width: 96px;
  height: auto;
  display: block;
  margin: 0 auto 20px;
}

.hero h1 {
  font-size: 2.5rem;
  margin: 0 0 12px;
  letter-spacing: -0.02em;
}

.hero .lead {
  color: var(--muted);
  font-size: 1.1rem;
  margin: 0;
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.card h2 {
  margin: 0;
  font-size: 1.25rem;
}

.card p {
  color: var(--muted);
  margin: 0;
  flex: 1;
}

.btn {
  display: inline-block;
  padding: 10px 16px;
  background: var(--accent);
  color: var(--accent-fg);
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
  text-align: center;
  transition: opacity 0.15s ease;
}

.btn:hover { opacity: 0.85; }

.btn.disabled {
  background: var(--border);
  color: var(--muted);
  cursor: not-allowed;
}

.site-footer {
  background: var(--footer-bg);
  color: var(--footer-fg);
  text-align: center;
  padding: 18px 16px;
  font-size: 0.875rem;
}

.site-footer .beian {
  color: var(--footer-fg);
  text-decoration: none;
  margin: 0 6px;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.site-footer .beian:hover { text-decoration: underline; }

.site-footer .beian-icon {
  height: 1em;
  width: auto;
  vertical-align: middle;
}