:root {
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #5f6368;
  --line: #e3e3e3;
  --accent: #1a5fb4;
  --card: #f7f8fa;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #16181c;
    --fg: #e8e8e8;
    --muted: #9aa0a6;
    --line: #2c2f35;
    --accent: #7cadf0;
    --card: #1e2126;
  }
}

* { box-sizing: border-box; }

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

.wrap {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 20px 80px;
}

header.site {
  border-bottom: 1px solid var(--line);
  margin-bottom: 48px;
}

header.site .wrap {
  padding-top: 20px;
  padding-bottom: 20px;
  display: flex;
  align-items: baseline;
  gap: 16px;
  flex-wrap: wrap;
}

header.site a.brand {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--fg);
  text-decoration: none;
  letter-spacing: 0.02em;
}

header.site nav {
  margin-left: auto;
  display: flex;
  gap: 20px;
  font-size: 0.9rem;
}

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

h1 {
  font-size: 1.8rem;
  line-height: 1.4;
  margin: 0 0 8px;
  letter-spacing: -0.01em;
}

h2 {
  font-size: 1.15rem;
  margin: 44px 0 12px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

h2:first-of-type { border-top: none; padding-top: 0; }

h3 { font-size: 1rem; margin: 28px 0 8px; }

p, ul, ol { margin: 0 0 16px; }
li { margin-bottom: 6px; }

.lede {
  font-size: 1.05rem;
  color: var(--muted);
  margin-bottom: 40px;
}

.updated {
  font-size: 0.85rem;
  color: var(--muted);
  margin-bottom: 40px;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 0 0 20px;
  font-size: 0.94rem;
}

th, td {
  text-align: left;
  padding: 10px 12px;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}

th {
  font-weight: 600;
  color: var(--muted);
  font-size: 0.85rem;
}

.table-scroll { overflow-x: auto; }

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 20px 22px;
  margin: 0 0 20px;
}

.card h3 { margin-top: 0; }
.card p:last-child { margin-bottom: 0; }

.todo {
  background: #fff3cd;
  border: 1px solid #e0c060;
  color: #6b5200;
  border-radius: 8px;
  padding: 14px 18px;
  margin: 0 0 20px;
  font-size: 0.94rem;
}

@media (prefers-color-scheme: dark) {
  .todo { background: #3a3218; border-color: #6b5a20; color: #f0d98a; }
}

footer.site {
  border-top: 1px solid var(--line);
  margin-top: 60px;
  padding: 24px 0 60px;
  font-size: 0.85rem;
  color: var(--muted);
}

footer.site .wrap { padding-bottom: 0; }
footer.site a { color: var(--muted); }