:root {
  color-scheme: light dark;
  --bg: #f5f6f8;
  --surface: #ffffff;
  --text: #17191f;
  --muted: #606672;
  --line: #d9dde5;
  --accent: #0a84ff;
  --accent-strong: #0067d6;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111318;
    --surface: #1b1f27;
    --text: #f3f5f8;
    --muted: #aeb5c2;
    --line: #303744;
    --accent: #5aa7ff;
    --accent-strong: #8fc3ff;
  }
}

* {
  box-sizing: border-box;
}

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

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

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

.shell {
  width: min(1040px, 100%);
  margin: 0 auto;
  padding: 40px 20px;
}

.hero {
  padding: 56px clamp(20px, 5vw, 64px);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 28px;
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--accent);
  font-weight: 700;
}

h1 {
  margin: 0;
  max-width: 820px;
  font-size: clamp(34px, 7vw, 72px);
  line-height: 1.08;
  letter-spacing: 0;
}

.lead {
  max-width: 760px;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 20px;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: transparent;
  color: var(--text);
  font-weight: 700;
}

.button.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}

.section {
  margin-top: 28px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
}

article,
.document section {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 22px;
}

h2 {
  margin: 0 0 16px;
  font-size: 26px;
  letter-spacing: 0;
}

h3 {
  margin: 0 0 8px;
  font-size: 19px;
  letter-spacing: 0;
}

p {
  margin: 0 0 14px;
}

p:last-child,
li:last-child {
  margin-bottom: 0;
}

ul {
  margin: 0;
  padding-left: 1.2rem;
}

li {
  margin-bottom: 8px;
}

.document {
  max-width: 860px;
}

.document h1 {
  margin: 22px 0 8px;
  font-size: clamp(34px, 7vw, 58px);
}

.document section {
  margin-top: 18px;
}

.toplink {
  font-weight: 700;
}

.updated {
  color: var(--muted);
}

.footer {
  margin-top: 30px;
  color: var(--muted);
  font-size: 14px;
}

@media (max-width: 620px) {
  .shell {
    padding: 24px 14px;
  }

  .hero {
    border-radius: 18px;
    padding: 34px 20px;
  }

  .lead {
    font-size: 17px;
  }

  article,
  .document section {
    border-radius: 14px;
    padding: 18px;
  }
}