:root {
  --bg: #fbfaf6;
  --paper: #fffdf9;
  --text: #151713;
  --muted: #5f625b;
  --line: #cfc8ba;
  --line-strong: #8f887c;
  --accent: #26352f;
  --link: #294f74;
}

* { box-sizing: border-box; }

html { background: var(--bg); }

body {
  margin: 0;
  font-family: Georgia, "Times New Roman", "Noto Serif", "Noto Serif CJK SC", serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.78;
  text-rendering: optimizeLegibility;
}

.container {
  max-width: 820px;
  margin: 0 auto;
  padding: 0 24px;
}

.site-header {
  border-top: 4px solid var(--accent);
  border-bottom: 1px solid var(--line);
  background: var(--paper);
}

.nav {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 24px;
  padding: 18px 0 16px;
}

.brand {
  color: var(--accent);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
  text-transform: uppercase;
  white-space: nowrap;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  justify-content: flex-end;
}

.nav-links a {
  color: var(--muted);
  font-size: 0.92rem;
  text-decoration: none;
}

.nav-links a:hover,
.nav-links a:focus {
  color: var(--text);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.hero {
  padding: 58px 0 42px;
  border-bottom: 1px solid var(--line);
  background: var(--paper);
}

main {
  padding: 46px 0 74px;
}

section {
  margin: 0 0 42px;
}

h1,
h2,
h3 {
  color: var(--accent);
  font-weight: 700;
}

h1 {
  max-width: 760px;
  margin: 0 0 14px;
  font-size: clamp(2rem, 4vw, 3.1rem);
  line-height: 1.13;
}

h2 {
  margin: 42px 0 14px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  font-size: 1.38rem;
  line-height: 1.25;
}

h3 {
  margin: 28px 0 8px;
  font-size: 1.08rem;
  line-height: 1.35;
}

p {
  margin: 0 0 18px;
}

a {
  color: var(--link);
  text-underline-offset: 3px;
}

ul,
ol {
  padding-left: 22px;
}

li {
  margin-bottom: 8px;
}

.subtitle {
  max-width: 760px;
  margin: 0 0 24px;
  color: var(--muted);
  font-size: 1.16rem;
  line-height: 1.62;
}

.meta {
  color: var(--muted);
  font-size: 0.96rem;
}

.definition-box,
.abstract {
  margin: 28px 0;
  padding: 18px 22px;
  border-top: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line);
  background: transparent;
}

.definition-box strong,
.abstract strong {
  color: var(--accent);
}

.index-list,
.bibliography {
  margin: 22px 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
  list-style: none;
}

.index-list li,
.bibliography li {
  margin: 0;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.index-list a,
.bibliography a {
  color: var(--accent);
  font-weight: 700;
  text-decoration: none;
}

.index-list a:hover,
.bibliography a:hover {
  text-decoration: underline;
}

.index-list p,
.bibliography p {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 0.96rem;
  line-height: 1.55;
}

.term {
  border-top: 1px solid var(--line);
  padding-top: 20px;
  margin-top: 20px;
}

.term h2 {
  margin-top: 0;
  padding-top: 0;
  border-top: 0;
}

.article-header {
  padding-bottom: 26px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 34px;
}

.article-kicker {
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 0.9rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.article-subtitle {
  margin: 0 0 18px;
  color: var(--muted);
  font-size: 1.15rem;
  line-height: 1.55;
}

.article-body {
  font-size: 1.04rem;
}

.article-body p {
  margin-bottom: 20px;
}

.article-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 18px;
  margin: 26px 0 0;
  color: var(--muted);
  font-size: 0.95rem;
}

code,
pre {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
}

pre {
  overflow-x: auto;
  margin: 16px 0 22px;
  padding: 16px 18px;
  border: 1px solid var(--line);
  background: var(--paper);
  font-size: 0.9rem;
  line-height: 1.55;
}

.site-footer {
  border-top: 1px solid var(--line);
  background: var(--paper);
  color: var(--muted);
  padding: 26px 0;
  font-size: 0.9rem;
}

@media (max-width: 720px) {
  .container {
    padding: 0 18px;
  }

  .nav {
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
  }

  .nav-links {
    justify-content: flex-start;
  }

  .hero {
    padding: 42px 0 34px;
  }

  main {
    padding-top: 34px;
  }
}