body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: #f8f9fa;
  color: #1a1a2e;
  padding-top: 70px;
}

.navbar-brand {
  font-weight: 700;
  letter-spacing: 1px;
  font-size: 1.4rem;
  margin-right: 1.5rem;
}

.navbar-brand i {
  color: #ffc107;
}

.nav-link {
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.5rem 0.75rem;
}

.nav-link.active {
  border-bottom: 3px solid #ffc107;
}

.navbar-nav {
  gap: 0.25rem;
}

.paper-card {
  background: #fff;
  border-radius: 16px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.06);
  padding: 2rem;
  margin-bottom: 2rem;
  border: 1px solid rgba(0, 0, 0, 0.04);
}

.section-title {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.section-title i {
  color: #ffc107;
}

.ref-title {
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.3;
  color: #0a0a23;
  margin-bottom: 0.5rem;
}

.ref-lead {
  font-size: 1.02rem;
  color: #495057;
  line-height: 1.7;
}

.ref-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.ref-list li {
  border-bottom: 1px solid #eef0f2;
}

.ref-list li:last-child {
  border-bottom: none;
}

.ref-list a {
  display: flex;
  align-items: baseline;
  gap: 0.9rem;
  padding: 0.85rem 0.5rem;
  text-decoration: none;
  color: #212529;
  border-radius: 8px;
  transition: background 0.15s, padding-left 0.15s;
}

.ref-list a:hover {
  background: #fff8e1;
  padding-left: 0.9rem;
}

.ref-list .ref-icon {
  color: #ffc107;
  flex: 0 0 auto;
}

.ref-list .ref-name {
  flex: 1;
  font-weight: 600;
}

.ref-list .ref-desc {
  display: block;
  font-weight: 400;
  font-size: 0.85rem;
  color: #868e96;
  margin-top: 0.15rem;
}

.md-content {
  font-size: 1.02rem;
  line-height: 1.75;
  color: #2b2b3a;
}

.md-content h1 {
  display: none;
}

.md-content h2 {
  font-size: 1.45rem;
  font-weight: 700;
  color: #0a0a23;
  margin: 2rem 0 1rem;
  padding-bottom: 0.4rem;
  border-bottom: 2px solid #f1f3f5;
}

.md-content h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: #0a0a23;
  margin: 1.5rem 0 0.75rem;
}

.md-content h4 {
  font-size: 1rem;
  font-weight: 700;
  margin: 1.25rem 0 0.6rem;
}

.md-content p {
  margin-bottom: 1rem;
}

.md-content ul,
.md-content ol {
  margin-bottom: 1rem;
  padding-left: 1.4rem;
}

.md-content li {
  margin-bottom: 0.35rem;
}

.md-content code {
  background: #f1f3f5;
  color: #c7254e;
  padding: 0.12rem 0.4rem;
  border-radius: 4px;
  font-size: 0.9em;
}

.md-content pre {
  background: #f6f8fa;
  color: #24292e;
  border: 1px solid #e6e8eb;
  padding: 1rem 1.2rem;
  border-radius: 10px;
  overflow-x: auto;
  margin-bottom: 1.25rem;
  font-size: 0.9rem;
  line-height: 1.55;
}

.md-content pre code {
  background: none;
  color: inherit;
  padding: 0;
  font-family: 'JetBrains Mono', 'Fira Code', 'Courier New', monospace;
  text-shadow: none;
}

.md-content table {
  width: 100%;
  margin: 1.25rem 0;
  border-collapse: collapse;
  font-size: 0.95rem;
}

.md-content table th,
.md-content table td {
  border: 1px solid #e6e8eb;
  padding: 0.45rem 0.65rem;
  vertical-align: top;
}

.md-content table tr:nth-child(even) td {
  background: #fbfbfc;
}

.md-content blockquote {
  border-left: 4px solid #ffc107;
  background: #fffdf5;
  padding: 0.75rem 1rem;
  margin: 1rem 0;
  color: #495057;
}

.md-content hr {
  margin: 2rem 0;
  border-color: #e6e8eb;
}

.md-content img {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
  margin: 0.5rem 0 1rem;
}

.md-content img.img-center {
  display: block;
  margin-left: auto;
  margin-right: auto;
}

.ref-source {
  font-size: 0.82rem;
  color: #adb5bd;
  margin-top: 2rem;
  padding-top: 1rem;
  border-top: 1px solid #eef0f2;
}

footer {
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.9rem;
}

footer a {
  color: #ffc107;
  text-decoration: none;
}