:root {
  --cu-gold: #CFB87C;
  --cu-gold-dark: #A88F4F;
  --cu-gold-soft: #F7F1E1;
  --cu-black: #0D0D0D;
  --cu-cream: #F7F5EE;
  --border: #E5E0D2;
  --text: #1A1A1A;
  --text-soft: #555;
  --text-mute: #888;
  --link: #6A4F0A;
}

* { box-sizing: border-box; }
html { font-size: 16px; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  color: var(--text);
  background: #fff;
  line-height: 1.6;
}

a { color: var(--link); text-decoration: underline; text-decoration-color: var(--cu-gold); text-underline-offset: 2px; }
a:hover { color: var(--cu-black); text-decoration-color: var(--cu-gold-dark); }

/* Layout */
.sidebar {
  position: fixed;
  top: 0; left: 0; bottom: 0;
  width: 320px;
  background: var(--cu-cream);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}
.sidebar-inner {
  display: flex;
  flex-direction: column;
  min-height: 100%;
  padding: 20px 22px 16px 22px;
}
.sidebar-brand {
  display: block;
  color: var(--cu-black);
  text-decoration: none;
  margin-bottom: 22px;
  border-bottom: 2px solid var(--cu-gold);
  padding-bottom: 14px;
}
.brand-logo {
  display: block;
  width: 100%;
  max-width: 260px;
  height: auto;
}
.brand-sub {
  display: block;
  font-size: 0.78rem;
  color: var(--text-soft);
  margin-top: 8px;
  letter-spacing: 0.3px;
  font-weight: 500;
}
.sidebar-group-label {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--cu-gold-dark);
  margin: 18px 0 8px 0;
  padding-bottom: 4px;
  border-bottom: 1px solid var(--border);
}
.sidebar-group-label:first-of-type { margin-top: 0; }

.chapters {
  list-style: none;
  padding: 0;
  margin: 0;
  flex: 1;
}
.chapter { margin-bottom: 6px; }
.chapter > details > summary {
  cursor: pointer;
  padding: 6px 4px;
  list-style: none;
  font-weight: 600;
  font-size: 0.92rem;
  color: var(--cu-black);
  border-radius: 3px;
}
.chapter > details > summary::-webkit-details-marker { display: none; }
.chapter > details > summary:hover { background: var(--cu-gold-soft); }
.ch-letter {
  display: inline-block;
  width: 22px;
  height: 22px;
  line-height: 22px;
  text-align: center;
  background: var(--cu-gold);
  color: var(--cu-black);
  font-size: 0.78rem;
  font-weight: 700;
  border-radius: 3px;
  margin-right: 8px;
  letter-spacing: 0;
}
.ch-letter.big {
  width: 36px; height: 36px; line-height: 36px; font-size: 1.05rem; margin-right: 14px;
}
.sections {
  list-style: none;
  padding: 0 0 0 30px;
  margin: 4px 0 8px 0;
  border-left: 1px solid var(--border);
}
.sections li { margin: 1px 0; }
.sections li a {
  display: block;
  padding: 4px 8px;
  font-size: 0.85rem;
  color: var(--text);
  text-decoration: none;
  border-radius: 3px;
  line-height: 1.35;
}
.sections li a:hover { background: var(--cu-gold-soft); }
.sections li.active a { background: var(--cu-gold); color: var(--cu-black); font-weight: 600; }
.sec-num { font-size: 0.78rem; color: var(--text-soft); margin-right: 4px; }
.sections li.active .sec-num { color: var(--cu-black); }

.pdf-buttons {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 18px;
}
.pdf-button {
  display: block;
  padding: 10px 14px;
  background: var(--cu-black);
  color: var(--cu-gold);
  border-radius: 4px;
  text-align: center;
  font-weight: 600;
  text-decoration: none;
  letter-spacing: 0.3px;
  font-size: 0.88rem;
}
.pdf-button:hover { background: #1F1F1F; color: var(--cu-gold); text-decoration: none; }
.pdf-icon { display: inline-block; margin-right: 6px; }

.last-updated {
  margin-top: 12px;
  font-size: 0.72rem;
  color: var(--text-mute);
  text-align: center;
  letter-spacing: 0.3px;
}

/* TOC group headers */
.toc-group-header {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--cu-gold-dark);
  margin: 36px 0 16px 0;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--cu-gold);
}
.toc-group-header:first-child { margin-top: 0; }

/* Content */
.content {
  margin-left: 320px;
  padding: 36px 56px 80px 56px;
  max-width: 880px;
}
.appendix-notice {
  background: #FFF8E5;
  border: 1px solid #E6D08A;
  border-left: 4px solid var(--cu-gold-dark);
  border-radius: 4px;
  margin-bottom: 18px;
  font-size: 0.86rem;
  color: #4D3F12;
}
.appendix-notice > summary {
  cursor: pointer;
  padding: 10px 14px;
  list-style: none;
  outline: none;
  font-weight: 500;
}
.appendix-notice > summary::-webkit-details-marker { display: none; }
.appendix-notice > summary::before {
  content: "▸ ";
  display: inline-block;
  margin-right: 4px;
  transition: transform 0.15s ease;
}
.appendix-notice[open] > summary::before {
  content: "▾ ";
}
.appendix-notice .notice-tag {
  display: inline-block;
  background: var(--cu-gold-dark);
  color: #fff;
  padding: 1px 7px;
  border-radius: 2px;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-right: 6px;
  vertical-align: 1px;
}
.appendix-notice p {
  margin: 0;
  padding: 0 14px 12px 14px;
  line-height: 1.5;
}
.appendix-notice a {
  color: #6A4F0A;
  text-decoration-color: var(--cu-gold-dark);
  font-weight: 600;
}

.breadcrumb {
  font-size: 0.85rem;
  color: var(--text-soft);
  margin-bottom: 22px;
}
.breadcrumb a { color: var(--text-soft); text-decoration: none; }
.breadcrumb a:hover { color: var(--cu-black); text-decoration: underline; }
.bc-sep { margin: 0 8px; color: var(--text-mute); }
.bc-current { color: var(--cu-black); font-weight: 600; }

.navbar {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 10px;
  margin-bottom: 28px;
  align-items: stretch;
}
.navbtn {
  display: block;
  padding: 10px 14px;
  text-decoration: none;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--cu-black);
  font-size: 0.85rem;
  line-height: 1.3;
}
.navbtn:hover { border-color: var(--cu-gold); background: var(--cu-gold-soft); text-decoration: none; }
.navbtn.disabled { opacity: 0.4; pointer-events: none; }
.navbtn.next { text-align: right; }
.navbtn .nav-label { display: block; font-size: 0.72rem; color: var(--text-soft); text-transform: uppercase; letter-spacing: 1px; }
.navbtn .nav-target { display: block; font-weight: 600; margin-top: 2px; }
.navbtn.index { display: flex; align-items: center; padding: 10px 18px; }
.navbtn.index .nav-label { text-transform: uppercase; letter-spacing: 1.5px; font-size: 0.75rem; color: var(--cu-black); }

/* Article body */
.section-header { margin-bottom: 36px; }
.section-number { font-size: 0.82rem; font-weight: 600; color: var(--cu-gold-dark); letter-spacing: 1.5px; text-transform: uppercase; margin-bottom: 8px; }
.section h1 { font-size: 2rem; margin: 0; line-height: 1.25; color: var(--cu-black); letter-spacing: -0.3px; font-weight: 700; }
.section h2 { font-size: 1.32rem; margin: 36px 0 14px 0; color: var(--cu-black); padding-top: 8px; border-top: 1px solid var(--border); padding-top: 18px; font-weight: 700; }
.section h2:first-of-type { border-top: none; padding-top: 0; }
.section h3 { font-size: 1.08rem; margin: 24px 0 10px 0; color: var(--cu-black); font-weight: 700; }
.section h4 { font-size: 0.98rem; margin: 18px 0 8px 0; color: var(--text); font-weight: 700; }
.section p { margin: 12px 0; }
.section ul, .section ol { padding-left: 24px; }
.section li { margin: 4px 0; }
.section blockquote {
  margin: 18px 0;
  padding: 12px 18px;
  background: var(--cu-gold-soft);
  border-left: 4px solid var(--cu-gold);
  color: var(--text);
  font-style: italic;
}
.section blockquote p { margin: 6px 0; }
.section code {
  background: #f3efe2;
  padding: 1px 5px;
  border-radius: 3px;
  font-size: 0.9em;
}
.section pre {
  background: #faf7ec;
  padding: 12px 16px;
  border-radius: 4px;
  overflow-x: auto;
  border: 1px solid var(--border);
  font-size: 0.86rem;
}
.section table {
  width: 100%;
  border-collapse: collapse;
  margin: 18px 0;
  font-size: 0.92rem;
}
.section th, .section td { padding: 8px 12px; border: 1px solid var(--border); text-align: left; vertical-align: top; }
.section th { background: var(--cu-gold-soft); font-weight: 700; }
.section figure { margin: 24px 0; padding: 12px; background: #fafaf6; border: 1px solid var(--border); border-radius: 4px; }
.section figure img { max-width: 100%; height: auto; display: block; }
.section figure.figure-single img { margin: 0 auto; }
.section figure.figure-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
}
.section figure.figure-grid > figure { margin: 0; padding: 0; background: transparent; border: none; }
.section figure.figure-grid figcaption { font-size: 0.78rem; color: var(--text-soft); margin-top: 6px; }
.section figcaption.figure-caption { margin-top: 10px; font-size: 0.86rem; color: var(--text-soft); }

/* Cross-references */
.xref, .evref, .cite {
  text-decoration: underline;
  text-decoration-color: var(--cu-gold);
  text-decoration-thickness: 1.2px;
  text-underline-offset: 2px;
  white-space: nowrap;
}
.xref { color: var(--cu-black); font-weight: 600; }
.evref { color: var(--link); }
.cite { color: var(--cu-black); }

/* Evidence anchor target */
.ev-anchor:target { background: var(--cu-gold); padding: 2px 4px; border-radius: 2px; }

/* TOC index page */
.index-page .section-lead { color: var(--text-soft); font-size: 1.05rem; margin-top: 12px; }
.index-page .thesis-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--cu-black);
  margin: 14px 0 0 0;
  line-height: 1.4;
  letter-spacing: -0.2px;
}
.hero-figure {
  margin: 28px 0 36px 0;
  padding: 14px;
  background: #fafaf6;
  border: 1px solid var(--border);
  border-radius: 6px;
}
.hero-figure img { display: block; width: 100%; height: auto; }
.hero-figure figcaption {
  margin-top: 12px;
  font-size: 0.86rem;
  color: var(--text-soft);
  line-height: 1.5;
}
.toc-chapters { list-style: none; padding: 0; margin: 32px 0 0 0; }
.toc-chapter { margin-bottom: 36px; }
.toc-chapter-title { display: flex; align-items: center; font-size: 1.18rem; margin: 0 0 14px 0; padding-bottom: 8px; border-bottom: 1px solid var(--border); color: var(--cu-black); }
.toc-sections { list-style: none; padding: 0 0 0 50px; margin: 0; }
.toc-sections li { margin: 4px 0; }
.toc-sections li a { display: block; padding: 6px 10px; color: var(--text); text-decoration: none; border-radius: 3px; }
.toc-sections li a:hover { background: var(--cu-gold-soft); color: var(--cu-black); }

/* Responsive */
@media (max-width: 980px) {
  .sidebar { position: static; width: 100%; height: auto; }
  .sidebar-inner { min-height: 0; }
  .content { margin-left: 0; padding: 24px 24px 60px 24px; }
}