:root {
  --fg: #1a1a1a;
  --muted: #5f6368;
  --accent: #1565c0;
  --border: #e0e0e0;
  --bg: #ffffff;
  --bg-soft: #f7f8fa;
  --max-width: 820px;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  color: var(--fg);
  background: var(--bg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Kaku Gothic ProN",
    "Hiragino Sans", Meiryo, sans-serif;
  line-height: 1.8;
  font-size: 16px;
}

.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--bg-soft);
}

.site-header .inner,
main,
.site-footer .inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

.site-header .inner { padding-top: 16px; padding-bottom: 16px; }

.site-header .brand {
  font-weight: 700;
  font-size: 1.05rem;
  text-decoration: none;
  color: var(--fg);
}

.site-header nav { margin-top: 8px; }

.site-header nav a {
  display: inline-block;
  margin-right: 16px;
  font-size: 0.9rem;
  color: var(--accent);
  text-decoration: none;
}

.site-header nav a:hover { text-decoration: underline; }

main { padding-top: 32px; padding-bottom: 64px; }

main h1 { font-size: 1.7rem; line-height: 1.4; margin-top: 0; }
main h2 { font-size: 1.25rem; margin-top: 2.2em; border-bottom: 1px solid var(--border); padding-bottom: 0.3em; }
main h3 { font-size: 1.05rem; margin-top: 1.6em; }

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

main blockquote {
  margin: 1.2em 0;
  padding: 0.6em 1em;
  border-left: 4px solid var(--accent);
  background: var(--bg-soft);
  color: var(--muted);
}

main table {
  border-collapse: collapse;
  width: 100%;
  margin: 1.2em 0;
  font-size: 0.92rem;
}

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

main th { background: var(--bg-soft); }

main hr { border: none; border-top: 1px solid var(--border); margin: 2em 0; }

main code {
  background: var(--bg-soft);
  padding: 0.1em 0.4em;
  border-radius: 4px;
  font-size: 0.9em;
}

.card-list { display: grid; gap: 16px; margin: 24px 0; }

.card {
  display: block;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 18px 20px;
  text-decoration: none;
  color: var(--fg);
  transition: border-color 0.15s, box-shadow 0.15s;
}

.card:hover { border-color: var(--accent); box-shadow: 0 2px 12px rgba(0,0,0,0.06); }
.card .card-title { font-weight: 700; font-size: 1.1rem; color: var(--accent); }
.card .card-desc { color: var(--muted); font-size: 0.92rem; margin-top: 4px; }

.site-footer {
  border-top: 1px solid var(--border);
  background: var(--bg-soft);
  color: var(--muted);
  font-size: 0.85rem;
}

.site-footer .inner { padding-top: 20px; padding-bottom: 28px; }