:root {
  --bg: #ffffff;
  --fg: #1f2328;
  --muted: #59636e;
  --link: #0b57d0;
  --border: #d8dee4;
  --note-bg: #f6f8fa;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15181c;
    --fg: #e6e8eb;
    --muted: #9aa4af;
    --link: #8ab4f8;
    --border: #30363d;
    --note-bg: #1e2329;
  }
}
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: system-ui, -apple-system, "Hiragino Sans", "Noto Sans JP", "Yu Gothic UI", sans-serif;
  font-size: 1.0625rem;
  line-height: 1.8;
  overflow-wrap: anywhere;
}
.site-header, main, .site-footer {
  max-width: calc(42.5rem + 32px); /* 本文幅 40em（本文 1.0625rem × 40）＋左右の余白 */
  margin: 0 auto;
  padding: 0 16px;
}
.site-header { padding-top: 20px; padding-bottom: 12px; border-bottom: 1px solid var(--border); }
.site-name { color: var(--fg); font-weight: 700; text-decoration: none; }
main { padding-top: 24px; padding-bottom: 48px; }
a { color: var(--link); }
h1 { font-size: 1.6rem; line-height: 1.4; margin: 0 0 8px; }
h2 { font-size: 1.3rem; line-height: 1.4; margin: 2em 0 0.5em; }
h3 { font-size: 1.1rem; margin: 1.6em 0 0.4em; }
img, video, iframe { max-width: 100%; height: auto; }
pre { overflow-x: auto; padding: 12px; background: var(--note-bg); border-radius: 6px; line-height: 1.5; }
code { font-size: 0.9em; }
table { display: block; overflow-x: auto; border-collapse: collapse; }
th, td { border: 1px solid var(--border); padding: 4px 8px; }
.meta { color: var(--muted); font-size: 0.875rem; margin: 0; }
.ad-disclosure { color: var(--muted); font-size: 0.875rem; }
.ad-disclosure--article {
  margin: 16px 0 24px;
  padding: 8px 12px;
  background: var(--note-bg);
  border-left: 3px solid var(--border);
}
.article-list { list-style: none; padding: 0; margin: 0; }
.article-list li { padding: 16px 0; border-bottom: 1px solid var(--border); }
.article-list a { font-weight: 700; font-size: 1.1rem; }
.article-list .summary { margin: 4px 0 0; }
.site-footer { padding-top: 16px; padding-bottom: 32px; border-top: 1px solid var(--border); font-size: 0.875rem; color: var(--muted); }
.site-footer nav { display: flex; flex-wrap: wrap; gap: 4px 16px; }
.site-footer p { margin: 4px 0; }