:root {
  --bg: #eef2f7;
  --ink: #111827;
  --muted: #4b5563;
  --accent: #2563eb;
  --card: #f8fafc;
  --line: #d6dee8;
  --font-title: "Spectral", "Georgia", "Times New Roman", serif;
  --font-body: "Source Sans 3", "Segoe UI", "Tahoma", sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  color: var(--ink);
  background: radial-gradient(1200px 600px at 10% 0%, #ffffff 0%, var(--bg) 55%, #e6edf6 100%);
  font-family: var(--font-body);
  line-height: 1.5;
}

.hero {
  border-bottom: 1px solid var(--line);
  padding: 32px 20px;
  background: linear-gradient(120deg, #f8fafc 0%, #e8f0fb 45%, #dbe7f8 100%);
}

.hero-inner {
  max-width: 980px;
  margin: 0 auto;
}

h1 {
  font-family: var(--font-title);
  font-size: 40px;
  margin: 0 0 6px 0;
  letter-spacing: 0.5px;
}

.subtitle {
  font-size: 18px;
  margin: 0 0 12px 0;
  color: var(--muted);
}

.meta {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 14px;
  color: var(--muted);
}

.note {
  margin-top: 12px;
  color: var(--muted);
}

main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 24px 20px 64px;
}

.rubric {
  background: var(--card);
  border: 1px solid var(--line);
  padding: 18px 20px;
  border-radius: 10px;
  box-shadow: 0 12px 30px rgba(0,0,0,0.06);
}

.rubric h1, .rubric h2, .rubric h3 {
  font-family: var(--font-title);
}

.rubric ul {
  padding-left: 20px;
}

.section-summary {
  margin: 6px 0 12px;
  color: var(--muted);
}

.docs {
  margin-top: 28px;
}

.doc-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 16px;
  margin: 18px 0;
  box-shadow: 0 10px 22px rgba(0,0,0,0.06);
}

.doc-meta h3 {
  margin: 0 0 8px 0;
  font-family: var(--font-title);
}

.doc-details {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 13px;
  color: var(--muted);
}

.doc-notes {
  margin: 8px 0 10px;
  color: var(--muted);
}

.doc-link {
  display: inline-block;
  padding: 8px 12px;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  border-radius: 6px;
  font-weight: 600;
}

.doc-link:focus, .doc-link:hover {
  opacity: 0.9;
}

.doc-embed {
  margin-top: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
  background: #fff;
}

.doc-image {
  display: block;
  width: 100%;
  height: auto;
}

@media (max-width: 720px) {
  h1 { font-size: 30px; }
  .doc-embed object { height: 520px; }
}


.cover {
  background: #f8fafc;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 18px 20px;
  margin: 18px 0 22px;
  box-shadow: 0 10px 22px rgba(0,0,0,0.06);
}

.cover-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px 16px;
  font-size: 15px;
}

.caption {
  padding: 6px 0;
  border-bottom: 1px dashed var(--line);
}

.toc-section {
  background: var(--card);
  border: 1px solid var(--line);
  padding: 16px 20px;
  border-radius: 10px;
  margin-bottom: 20px;
}

.toc {
  columns: 2;
  column-gap: 24px;
  padding-left: 18px;
  font-size: 14px;
  line-height: 1.4;
}

.toc li {
  break-inside: avoid;
  margin: 8px 0;
}

.toc a {
  color: var(--ink);
  text-decoration: none;
}

.toc a:hover {
  text-decoration: underline;
}

.toc a span {
  font-weight: 600;
}

@media (max-width: 720px) {
  .cover-inner { grid-template-columns: 1fr; }
  .toc { columns: 1; }
}


.cite, .cite-page {
  display: inline-block;
  padding: 2px 6px;
  border-radius: 4px;
  background: #dbeafe;
  color: #1e3a8a;
  text-decoration: none;
  font-size: 0.9em;
  margin-left: 4px;
}

.cite-page {
  background: #f3f4f6;
  border: 1px solid var(--line);
}

.cite:hover, .cite-page:hover {
  text-decoration: underline;
}
