:root {
  --bg: #fafaf7;
  --fg: #1a1a1a;
  --muted: #6b6b6b;
  --accent: #c1272d;
  --card-bg: #ffffff;
  --card-border: #e8e6e0;
  --max-width: 720px;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family:
    "PingFang SC",
    "Hiragino Sans GB",
    "Microsoft YaHei",
    "Source Han Sans CN",
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 4rem 1.25rem 3rem;
}

header {
  text-align: center;
  margin-bottom: 3rem;
}

h1 {
  font-size: clamp(1.875rem, 5vw, 2.5rem);
  font-weight: 600;
  margin: 0 0 1rem;
  letter-spacing: -0.01em;
}

.brand-zh {
  color: var(--fg);
}

.brand-divider {
  margin: 0 0.5rem;
  color: var(--accent);
  font-weight: 400;
}

.brand-en {
  color: var(--muted);
  font-weight: 400;
  letter-spacing: 0.02em;
}

.tagline {
  font-size: 1.0625rem;
  color: var(--fg);
  margin: 0;
  line-height: 1.7;
}

.tagline-sub {
  font-size: 0.875rem;
  color: var(--muted);
}

/* Channel grid */
.channels {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 0.75rem;
  margin-bottom: 3.5rem;
}

.channel {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 6px;
  padding: 1.25rem 1rem;
  text-align: center;
  transition:
    transform 0.15s ease,
    border-color 0.15s ease;
}

.channel:hover {
  border-color: var(--accent);
  transform: translateY(-1px);
}

.channel h2 {
  margin: 0 0 0.5rem;
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--fg);
}

.channel p {
  margin: 0;
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.5;
}

/* CTA */
.cta {
  text-align: center;
  padding: 2.5rem 1rem;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 6px;
  margin-bottom: 3rem;
}

.cta h2 {
  margin: 0 0 0.5rem;
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.cta-prompt {
  margin: 0 0 1.5rem;
  color: var(--fg);
  font-size: 1rem;
}

.cta-button {
  display: inline-block;
  background: var(--accent);
  color: #ffffff;
  padding: 0.75rem 2rem;
  border-radius: 4px;
  text-decoration: none;
  font-size: 1rem;
  font-weight: 500;
  transition: background 0.15s ease;
}

.cta-button:hover {
  background: #a01f24;
}

.cta-button:focus-visible {
  outline: 3px solid var(--fg);
  outline-offset: 2px;
}

.cta-note {
  margin: 1rem 0 0;
  font-size: 0.8125rem;
  color: var(--muted);
}

footer {
  text-align: center;
  font-size: 0.875rem;
  color: var(--fg);
  padding-top: 1.5rem;
  border-top: 1px solid var(--card-border);
}

footer p {
  margin: 0;
}

.footer-meta {
  margin-top: 0.5rem !important;
  font-size: 0.75rem;
  color: var(--muted);
}

@media (max-width: 480px) {
  main {
    padding: 2.5rem 1rem 2rem;
  }
  header {
    margin-bottom: 2rem;
  }
  .channels {
    grid-template-columns: repeat(2, 1fr);
    margin-bottom: 2.5rem;
  }
  .cta {
    padding: 2rem 0.75rem;
  }
}