:root {
  color-scheme: light dark;
  --bg: #f7f8fa;
  --surface: #ffffff;
  --text: #17202a;
  --muted: #5c6773;
  --border: #dfe4ea;
  --accent: #0a7cff;
  --accent-quiet: #eaf3ff;
  --shadow: 0 18px 50px rgba(23, 32, 42, 0.08);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1115;
    --surface: #171a20;
    --text: #f2f5f8;
    --muted: #a6b0bc;
    --border: #2c333d;
    --accent: #62a8ff;
    --accent-quiet: #142236;
    --shadow: none;
  }
}

* {
  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", "Microsoft YaHei", sans-serif;
  line-height: 1.65;
}

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

a:hover {
  text-decoration: underline;
}

.page {
  width: min(960px, calc(100% - 32px));
  margin: 0 auto;
  padding: 32px 0 56px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 32px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 700;
  font-size: 18px;
}

.brand-mark {
  width: 34px;
  height: 34px;
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  display: grid;
  place-items: center;
  font-weight: 800;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  font-size: 14px;
}

.hero,
.document {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.hero {
  padding: clamp(28px, 6vw, 56px);
}

.hero h1 {
  margin: 0 0 12px;
  font-size: clamp(32px, 5vw, 56px);
  line-height: 1.08;
  letter-spacing: 0;
}

.hero p {
  margin: 0;
  color: var(--muted);
  font-size: 18px;
  max-width: 720px;
}

.link-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-top: 24px;
}

.link-card {
  display: block;
  padding: 20px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  color: var(--text);
}

.link-card strong {
  display: block;
  margin-bottom: 6px;
  font-size: 17px;
}

.link-card span {
  color: var(--muted);
  font-size: 14px;
}

.document {
  padding: clamp(24px, 5vw, 48px);
}

.document header {
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 32px;
}

.document h1 {
  margin: 0 0 8px;
  font-size: clamp(30px, 4vw, 44px);
  line-height: 1.14;
  letter-spacing: 0;
}

.meta {
  color: var(--muted);
  margin: 0;
}

.language-block + .language-block {
  margin-top: 44px;
  padding-top: 36px;
  border-top: 1px solid var(--border);
}

h2 {
  margin: 28px 0 12px;
  font-size: 22px;
  line-height: 1.25;
  letter-spacing: 0;
}

h3 {
  margin: 22px 0 8px;
  font-size: 17px;
  line-height: 1.35;
  letter-spacing: 0;
}

p {
  margin: 0 0 14px;
}

ul {
  margin: 0 0 18px;
  padding-left: 22px;
}

li + li {
  margin-top: 6px;
}

.notice {
  border: 1px solid var(--border);
  background: var(--accent-quiet);
  border-radius: 8px;
  padding: 16px;
  margin: 22px 0;
}

.footer {
  color: var(--muted);
  font-size: 14px;
  margin-top: 28px;
  text-align: center;
}

@media (max-width: 640px) {
  .page {
    width: min(100% - 24px, 960px);
    padding-top: 20px;
  }

  .topbar {
    align-items: flex-start;
    flex-direction: column;
  }

  .link-grid {
    grid-template-columns: 1fr;
  }
}