:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --ink: #1f1f1f;
  --muted: #5f5f5f;
  --accent: #c4302b;
  --line: #e3e3e3;
  --code-bg: #f2f2f2;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #161616;
    --ink: #ececec;
    --muted: #a8a8a8;
    --accent: #ff7a6b;
    --line: #333333;
    --code-bg: #262626;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.75 system-ui, "Segoe UI", "Hiragino Sans", "Noto Sans JP", sans-serif;
}

main {
  max-width: 760px;
  margin: 0 auto;
  padding: 40px 16px 64px;
}

h1 { font-size: 1.8rem; line-height: 1.3; margin: 0 0 12px; }
h2 { font-size: 1.15rem; margin: 32px 0 8px; }
a { color: var(--accent); }
code { background: var(--code-bg); color: var(--ink); padding: 1px 5px; border-radius: 4px; font-size: .9em; overflow-wrap: anywhere; }
hr { border: 0; border-top: 1px solid var(--line); margin: 48px 0; }
li + li { margin-top: 6px; }
.updated, .back { color: var(--muted); font-size: .9rem; }

.links { display: flex; flex-wrap: wrap; gap: 12px 20px; align-items: center; margin-top: 24px; }
.button {
  display: inline-block;
  padding: 8px 16px;
  border-radius: 8px;
  background: var(--accent);
  color: var(--bg);
  text-decoration: none;
  font-weight: 600;
}