:root {
  --ink: #1a1a1a;
  --muted: #666;
  --faint: #999;
  --rule: #e4e4e4;
  --link: #1a5fb4;
  --bg: #ffffff;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  font-family: -apple-system, "Helvetica Neue", Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.62;
  font-size: 18px;
  margin: 0;
  padding: 0 1.25rem;
}
main, .site-header, .site-footer { max-width: 40rem; margin: 0 auto; }

.site-header { padding: 3.2rem 0 1.4rem; }
.site-title {
  display: inline-block;
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--ink);
  text-decoration: none;
}
.tagline { color: var(--muted); font-size: 1rem; margin: 0.8rem 0 0; }

.header-bar { display: flex; justify-content: space-between; align-items: baseline; gap: 1rem; flex-wrap: wrap; }
.site-nav { display: flex; gap: 1.1rem; font-size: 0.95rem; }
.site-nav a { color: var(--muted); }
.site-nav a:hover { color: var(--link); }

.page { border-top: 1px solid var(--rule); padding-top: 1.6rem; }
.page h1 { font-size: 1.9rem; line-height: 1.2; margin: 0 0 1rem; letter-spacing: -0.01em; }
.page p { margin: 0.9rem 0; }

a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }

.intro { border-top: 1px solid var(--rule); padding-top: 1.6rem; }
.intro p { margin: 0.85rem 0; }

/* home factor list */
.factor-list { margin: 2.2rem 0 3rem; }
.factor-list ol { list-style: none; counter-reset: none; padding: 0; margin: 0; }
.factor-list ol li { padding: 0.55rem 0; border-top: 1px solid var(--rule); }
.factor-list ol li a { font-size: 1.18rem; font-weight: 600; color: var(--ink); }
.factor-list ol li a:hover { color: var(--link); text-decoration: none; }
.factor-list .num { color: var(--faint); font-weight: 700; margin-right: 0.5rem; }
.factor-list .gloss { display: block; color: var(--muted); font-size: 0.95rem; font-weight: 400; margin-top: 0.1rem; }
.factor-list .beyond { list-style: none; padding: 1.4rem 0 0; margin: 0; }
.factor-list .beyond li { padding: 0.3rem 0; }
.factor-list .beyond a { font-weight: 600; }

/* factor page */
.factor { padding-top: 1.2rem; }
.factor-num {
  font-size: 3.2rem;
  font-weight: 800;
  color: var(--faint);
  line-height: 1;
  margin: 0 0 0.2rem;
}
.factor h1 { font-size: 1.9rem; line-height: 1.2; margin: 0 0 1rem; letter-spacing: -0.01em; }
.factor-lead {
  font-size: 1.3rem;
  line-height: 1.4;
  font-weight: 500;
  color: var(--ink);
  margin: 0 0 1.4rem;
  padding-bottom: 1.3rem;
  border-bottom: 1px solid var(--rule);
}
.factor p { margin: 0.9rem 0; }
.factor code { background: #f4f4f4; padding: 0.05em 0.35em; border-radius: 3px; font-size: 0.9em; }

/* blog */
.post-date { color: var(--faint); font-size: 0.9rem; margin: 0 0 1.3rem; }
.post-list .postdate { display: block; color: var(--faint); font-size: 0.82rem; margin-top: 0.25rem; }
.empty { color: var(--muted); }

.pager {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
  margin-top: 3rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--rule);
  font-size: 0.95rem;
}
.pager-prev { text-align: left; flex: 1; }
.pager-next { text-align: right; flex: 1; }
.pager-home { color: var(--faint); }

.site-footer {
  margin-top: 3.5rem;
  padding: 1.4rem 0 3rem;
  border-top: 1px solid var(--rule);
  color: var(--muted);
  font-size: 0.9rem;
}

@media (max-width: 34rem) {
  body { font-size: 17px; }
  .factor-num { font-size: 2.6rem; }
  .pager { flex-direction: column; gap: 0.5rem; }
  .pager-next, .pager-prev { text-align: left; }
}