:root {
  --bg: #f1f5f9;
  --ink: #1e293b;
  --muted: #64748b;
  --line: #e2e8f0;
  --accent: #2563eb;
  --paper: #fff;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "Noto Sans JP", "Hiragino Sans", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.75;
  font-size: 15px;
}
.wrap {
  max-width: 42rem;
  margin: 0 auto;
  padding: 28px 20px 64px;
}
nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
  font-size: 13px;
  margin-bottom: 28px;
}
nav a { color: var(--accent); }
h1 {
  font-size: 1.55rem;
  margin: 0 0 8px;
}
.meta {
  color: var(--muted);
  font-size: 13px;
  margin: 0 0 28px;
}
h2 {
  font-size: 1.15rem;
  margin: 2rem 0 0.6rem;
  padding-top: 0.4rem;
  border-top: 1px solid var(--line);
}
h2:first-of-type { border-top: none; padding-top: 0; }
p, ul { margin: 0 0 0.9rem; }
ul { padding-left: 1.2rem; }
li + li { margin-top: 0.3rem; }
a { color: var(--accent); }
.card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 24px 22px 8px;
}