:root {
  --accent: #4f46e5;
  --accent-soft: #eef2ff;
  --text: #1f2937;
  --text-muted: #6b7280;
  --border: #e5e7eb;
  --code-bg: #f3f4f6;
  --bg: #ffffff;
}

* {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Noto Sans SC", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.75;
  font-size: 16px;
}

/* ---------- header / footer ---------- */
.page-header {
  border-bottom: 1px solid var(--border);
}

.page-header .inner {
  max-width: 760px;
  margin: 0 auto;
  padding: 22px 20px 14px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.brand {
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
  font-size: 15px;
}

.brand:hover {
  text-decoration: underline;
}

.lang-switch {
  font-size: 14px;
}

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

.lang-switch a:hover {
  text-decoration: underline;
}

.page-footer {
  border-top: 1px solid var(--border);
}

.page-footer .inner {
  max-width: 760px;
  margin: 0 auto;
  padding: 18px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 13px;
  color: var(--text-muted);
}

.page-footer nav a {
  color: var(--text-muted);
  text-decoration: none;
  margin-left: 14px;
}

.page-footer nav a:hover {
  color: var(--accent);
  text-decoration: underline;
}

/* ---------- document pages ---------- */
main {
  max-width: 760px;
  margin: 0 auto;
  padding: 32px 20px 48px;
}

h1 {
  font-size: 28px;
  line-height: 1.3;
  margin: 0 0 8px;
}

.meta {
  color: var(--text-muted);
  font-size: 14px;
  margin: 0 0 28px;
}

.meta p {
  margin: 2px 0;
}

.meta strong {
  color: var(--text-muted);
}

h2 {
  font-size: 20px;
  margin: 40px 0 12px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}

h3 {
  font-size: 17px;
  margin: 24px 0 8px;
}

p {
  margin: 10px 0;
}

ul,
ol {
  margin: 10px 0;
  padding-left: 24px;
}

li {
  margin: 4px 0;
}

strong {
  color: #111827;
}

a {
  color: var(--accent);
}

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  font-size: 0.9em;
  background: var(--code-bg);
  padding: 2px 5px;
  border-radius: 4px;
  word-break: break-all;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 14px 0;
  font-size: 14.5px;
}

th,
td {
  border: 1px solid var(--border);
  padding: 8px 10px;
  text-align: left;
  vertical-align: top;
}

th {
  background: #f9fafb;
  font-weight: 600;
}

tr:nth-child(even) td {
  background: #fafafa;
}

blockquote {
  margin: 12px 0;
  padding: 2px 16px;
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
  border-radius: 0 6px 6px 0;
}

/* ---------- landing page ---------- */
.hero {
  padding: 40px 0 4px;
}

.hero h1 {
  font-size: 32px;
  margin-bottom: 4px;
}

.hero p.sub {
  color: var(--text-muted);
  margin-top: 0;
}

.cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin: 28px 0 48px;
}

.card {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px 24px;
  background: #fcfcfd;
}

.card h2 {
  border: none;
  padding: 0;
  margin: 0 0 4px;
  font-size: 18px;
}

.card .desc {
  color: var(--text-muted);
  font-size: 14px;
  margin: 0 0 10px;
}

.card ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.card li {
  margin: 6px 0;
}

.card a {
  text-decoration: none;
}

.card a:hover {
  text-decoration: underline;
}

.lang-tag {
  font-size: 12px;
  background: var(--accent-soft);
  color: var(--accent);
  padding: 1px 7px;
  border-radius: 4px;
  margin-right: 6px;
  white-space: nowrap;
}

@media (max-width: 480px) {
  body {
    font-size: 15px;
  }

  h1 {
    font-size: 24px;
  }

  .hero h1 {
    font-size: 26px;
  }

  main {
    padding: 24px 16px 40px;
  }
}