:root {
  --bg: #0d1117;
  --bg-raised: #12181f;
  --border: #232b34;
  --text: #e6e8eb;
  --text-dim: #9aa4b0;
  --text-faint: #6b7480;
  --accent: #4d94a8;
  --accent-dim: #35707f;
  --font-ui: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  --font-serif: "Source Serif 4", Georgia, "Times New Roman", serif;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-ui);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  padding: 1.5rem 2rem 0;
}

.header-inner {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
  max-width: 960px;
  margin: 0 auto;
}

.brand h1 {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.6rem;
  margin: 0;
  letter-spacing: 0.01em;
}

.tagline {
  margin: 0.15rem 0 0;
  font-size: 0.85rem;
  color: var(--text-dim);
}

.updated {
  font-size: 0.8rem;
  color: var(--text-faint);
  white-space: nowrap;
}

.category-tabs {
  max-width: 960px;
  margin: 1.25rem auto 0;
  display: flex;
  gap: 0.25rem;
  flex-wrap: wrap;
  border-bottom: none;
}

.tab-btn {
  background: none;
  border: none;
  color: var(--text-dim);
  font-family: var(--font-ui);
  font-size: 0.9rem;
  font-weight: 500;
  padding: 0.5rem 0.85rem;
  cursor: pointer;
  border-bottom: 2px solid transparent;
  transition: color 0.15s ease, border-color 0.15s ease;
}

.tab-btn:hover {
  color: var(--text);
}

.tab-btn.active {
  color: var(--text);
  border-bottom-color: var(--accent);
}

.region-chips {
  max-width: 960px;
  margin: 0 auto;
  padding: 0.75rem 0 1rem;
  display: flex;
  gap: 0.4rem;
  flex-wrap: wrap;
}

.chip-btn {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-dim);
  font-family: var(--font-ui);
  font-size: 0.78rem;
  padding: 0.28rem 0.7rem;
  border-radius: 999px;
  cursor: pointer;
  transition: border-color 0.15s ease, color 0.15s ease, background 0.15s ease;
}

.chip-btn:hover {
  color: var(--text);
  border-color: var(--text-faint);
}

.chip-btn.active {
  color: var(--accent);
  border-color: var(--accent-dim);
  background: rgba(77, 148, 168, 0.1);
}

main {
  max-width: 960px;
  margin: 0 auto;
  padding: 1.5rem 2rem 3rem;
}

.state-message {
  display: none;
  color: var(--text-dim);
  font-size: 0.95rem;
  padding: 3rem 0.5rem;
  text-align: center;
  border: 1px dashed var(--border);
  border-radius: 8px;
}

.cluster-list {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.cluster-card {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.25rem 1.5rem;
}

.cluster-headline {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  font-weight: 600;
  line-height: 1.35;
  margin: 0 0 0.6rem;
  color: var(--text);
}

.cluster-summary {
  font-size: 0.95rem;
  color: var(--text-dim);
  margin: 0 0 1rem;
}

.cluster-sources {
  list-style: none;
  margin: 0;
  padding: 0.75rem 0 0;
  border-top: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.source-item {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  font-size: 0.85rem;
  flex-wrap: wrap;
}

.source-item a {
  color: var(--text);
}

.source-item a:hover {
  color: var(--accent);
}

.source-region-tag {
  font-size: 0.68rem;
  color: var(--text-faint);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.05rem 0.4rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  white-space: nowrap;
}

.cluster-card.multi-source {
  border-color: var(--accent-dim);
}

.compare-section {
  margin: 0 0 1rem;
  padding-top: 0.5rem;
}

.source-badge {
  display: inline-block;
  font-size: 0.72rem;
  color: var(--accent);
  border: 1px solid var(--accent-dim);
  border-radius: 999px;
  padding: 0.15rem 0.6rem;
  margin-right: 0.6rem;
  letter-spacing: 0.01em;
}

.compare-toggle {
  background: none;
  border: none;
  color: var(--text-dim);
  font-family: var(--font-ui);
  font-size: 0.8rem;
  cursor: pointer;
  padding: 0.15rem 0;
}

.compare-toggle:hover {
  color: var(--accent);
}

.compare-panel {
  display: none;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 0.75rem;
  margin-top: 0.75rem;
}

.compare-panel.expanded {
  display: grid;
}

.compare-item {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.75rem 0.9rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.compare-item-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.compare-item-name {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text);
}

.compare-item-title {
  font-size: 0.85rem;
  color: var(--text);
  margin: 0;
  line-height: 1.35;
}

.compare-item-excerpt {
  font-size: 0.78rem;
  color: var(--text-dim);
  margin: 0;
  line-height: 1.4;
}

.compare-item-meta {
  margin-top: auto;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem;
  font-size: 0.72rem;
  color: var(--text-faint);
}

.compare-item-meta a {
  white-space: nowrap;
}

.site-footer {
  max-width: 960px;
  margin: 0 auto;
  padding: 1rem 2rem 2.5rem;
  color: var(--text-faint);
  font-size: 0.78rem;
  border-top: 1px solid var(--border);
}

@media (max-width: 640px) {
  .site-header {
    padding: 1.25rem 1rem 0;
  }

  main {
    padding: 1.25rem 1rem 2.5rem;
  }

  .site-footer {
    padding: 1rem 1rem 2rem;
  }

  .header-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .cluster-card {
    padding: 1rem 1.1rem;
  }
}