* { box-sizing: border-box; }
html { font-size: 18px; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: #fafafa;
  color: #1a1a1a;
  line-height: 1.6;
}
main { max-width: 640px; margin: 0 auto; padding: 3rem 1.5rem 5rem; }
.toc h1 { font-size: 2.25rem; margin: 0 0 0.25rem; }
.subtitle { font-size: 1.1rem; color: #555; margin: 0 0 0.5rem; }
.author, .stats { color: #888; font-size: 0.9rem; margin: 0.25rem 0; }
.stats { margin-bottom: 2rem; }
.toc section { margin: 2rem 0; }
.toc section h2 { font-size: 1.1rem; color: #555; font-weight: 500; border-bottom: 1px solid #ddd; padding-bottom: 0.5rem; margin-bottom: 0.5rem; }
.toc-row {
  display: flex;
  justify-content: space-between;
  padding: 0.75rem 0;
  text-decoration: none;
  color: #1a1a1a;
  border-bottom: 1px solid #eee;
}
.toc-row:hover { background: #f0f0f0; }
.toc-row .time { color: #999; font-size: 0.85rem; }
.chapter h1 { font-size: 1.75rem; margin: 0 0 1rem; line-height: 1.25; }
.chapter h2 { font-size: 1.3rem; margin: 2.5rem 0 1rem; }
.chapter h3 { font-size: 1.1rem; margin: 2rem 0 0.75rem; }
.chapter p { margin: 0 0 1rem; }
.chapter blockquote { border-left: 3px solid #ddd; padding-left: 1rem; color: #555; margin: 1.5rem 0; }
.chapter hr { border: none; border-top: 1px solid #ddd; margin: 2rem 0; }
.meta { color: #aaa; font-size: 0.85rem; margin-bottom: 1.5rem; }
.part-label { color: #888; font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 0.5rem; }
.chapter-nav {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 4rem;
  padding-top: 2rem;
  border-top: 1px solid #ddd;
  font-size: 0.95rem;
}
.chapter-nav a { color: #555; text-decoration: none; }
.chapter-nav a:hover { color: #000; }
.nav-toc { font-weight: 500; }
@media (max-width: 480px) {
  html { font-size: 17px; }
  main { padding: 2rem 1rem 4rem; }
}