:root {
  --ink: #1f2937; --muted: #6b7280; --brand: #1f4e78; --accent: #2e7d32;
  --bg: #ffffff; --soft: #f3f6f9; --line: #e5e7eb;
}
@media (prefers-color-scheme: dark) {
  :root { --ink: #e5e7eb; --muted: #9ca3af; --brand: #8ab4e0; --accent: #81c784;
          --bg: #111827; --soft: #1f2937; --line: #374151; }
}
* { box-sizing: border-box; }
body { margin: 0; font-family: "Yu Gothic", "Hiragino Sans", "Meiryo", sans-serif;
       color: var(--ink); background: var(--bg); line-height: 1.8; }
.wrap { max-width: 860px; margin: 0 auto; padding: 0 16px; }
a { color: var(--brand); }
.site-header { background: var(--brand); color: #fff; padding: 20px 0; }
@media (prefers-color-scheme: dark) { .site-header { background: #16324d; } }
.logo { color: #fff; font-size: 1.4rem; font-weight: 700; text-decoration: none; }
.tagline { margin: 4px 0 0; opacity: .85; font-size: .9rem; }
.pr-note { font-size: .8rem; color: var(--muted); margin-top: 8px; }
.intro h1 { font-size: 1.5rem; line-height: 1.5; margin: 24px 0 8px; }
.section-title { border-left: 4px solid var(--brand); padding-left: 10px; margin-top: 32px; }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 16px; }
.card { display: block; padding: 16px; border: 1px solid var(--line); border-radius: 10px;
        background: var(--soft); color: var(--ink); text-decoration: none; }
.card h3 { font-size: 1rem; margin: 8px 0; line-height: 1.5; }
.card p { margin: 0; font-size: .85rem; color: var(--muted); }
.card.draft { opacity: .55; }
.tag { font-size: .75rem; background: var(--brand); color: #fff; padding: 2px 8px; border-radius: 99px; }
article h1 { font-size: 1.5rem; line-height: 1.5; }
article h2 { border-bottom: 2px solid var(--line); padding-bottom: 4px; margin-top: 36px; }
pre { background: var(--soft); border: 1px solid var(--line); padding: 12px; border-radius: 8px;
      overflow-x: auto; font-size: .9rem; }
table { border-collapse: collapse; width: 100%; font-size: .9rem; }
th, td { border: 1px solid var(--line); padding: 6px 8px; }
th { background: var(--brand); color: #fff; }
td.num { text-align: right; }
.box { border: 1px solid var(--line); background: var(--soft); border-radius: 10px; padding: 12px 16px; }
.pr-box { border: 2px dashed var(--accent); border-radius: 10px; padding: 12px 16px; }
.site-footer { margin-top: 48px; padding: 24px 0; border-top: 1px solid var(--line);
               color: var(--muted); font-size: .85rem; }