:root {
  color-scheme: dark;
  --bg: #0f1216;
  --card: #171b21;
  --border: #262c34;
  --text: #e4e7eb;
  --muted: #8a94a3;
  --accent: #5ec2a3;
  --critical: #ef6461;
  --critical-bg: #241615;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

header {
  position: sticky;
  top: 0;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  padding: 1rem 1.25rem;
  z-index: 10;
}

header h1 {
  margin: 0 0 0.5rem 0;
  font-size: 1.2rem;
}

.stats {
  display: flex;
  gap: 1rem;
  align-items: center;
  flex-wrap: wrap;
  color: var(--muted);
  font-size: 0.85rem;
}

.stats form { margin: 0; }

.stats button {
  background: var(--accent);
  color: #0f1216;
  border: none;
  border-radius: 6px;
  padding: 0.35rem 0.75rem;
  font-weight: 600;
  cursor: pointer;
}

.stats button:disabled {
  background: var(--border);
  color: var(--muted);
  cursor: not-allowed;
}

.filter-bar {
  max-width: 1440px;
  margin: 0 auto;
  padding: 1rem 1.25rem 0;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.filter-label {
  color: var(--muted);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-right: 0.25rem;
}

.filter-tag {
  background: var(--card);
  border: 1px solid var(--border);
  color: var(--muted);
  border-radius: 999px;
  padding: 0.3rem 0.75rem;
  font-size: 0.78rem;
  cursor: pointer;
  transition: border-color 0.15s ease, color 0.15s ease;
}

.filter-tag:hover {
  border-color: var(--accent);
  color: var(--text);
}

.filter-tag.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #0f1216;
  font-weight: 600;
}

.must-read-section {
  max-width: 1440px;
  margin: 0 auto;
  padding: 1.25rem 1.25rem 0;
}

.must-read-section h2 {
  margin: 0 0 0.75rem;
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--critical);
}

.must-read-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.75rem;
}

.card.must-read {
  background: var(--critical-bg);
  border-color: var(--critical);
}

.card.must-read .title:hover { color: var(--critical); }

.card.must-read .tag {
  background: #3a1f1e;
  color: var(--critical);
}

main.columns {
  max-width: 1440px;
  margin: 0 auto;
  padding: 1.25rem;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.25rem;
  align-items: start;
}

.column {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  min-width: 0;
}

.column h2 {
  margin: 0 0 0.25rem;
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--muted);
  position: sticky;
  top: 3.6rem;
  background: var(--bg);
  padding: 0.25rem 0;
}

@media (max-width: 980px) {
  main.columns {
    grid-template-columns: 1fr;
  }
  .column h2 { position: static; }
  .must-read-grid {
    grid-template-columns: 1fr;
  }
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.9rem 1.1rem;
}

.title {
  color: var(--text);
  text-decoration: none;
  font-weight: 600;
  font-size: 1.02rem;
  display: block;
}

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

.meta {
  margin-top: 0.35rem;
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
  font-size: 0.78rem;
  color: var(--muted);
}

.tag {
  background: #1e2833;
  color: var(--accent);
  border-radius: 4px;
  padding: 0.05rem 0.4rem;
}

.summary {
  margin: 0.5rem 0 0;
  color: var(--muted);
  font-size: 0.88rem;
  line-height: 1.4;
}

.empty { color: var(--muted); }