/* LLM News Tracker — Stylesheet */
/* Clean, professional, information-dense design */

:root {
  --bg: #ffffff;
  --bg-secondary: #f8f9fa;
  --text: #1a1a2e;
  --text-secondary: #64748b;
  --border: #e2e8f0;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --tag-bg: #eff6ff;
  --tag-text: #2563eb;
  --success: #059669;
  --warning: #d97706;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1);
  --radius: 8px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f172a;
    --bg-secondary: #1e293b;
    --text: #e2e8f0;
    --text-secondary: #94a3b8;
    --border: #334155;
    --accent: #3b82f6;
    --accent-hover: #60a5fa;
    --tag-bg: #1e3a5f;
    --tag-text: #93c5fd;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.4);
  }
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
               "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
}

/* Header */
header {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  padding: 24px 0;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
}

.header-inner {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 24px;
}

header h1 {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text);
}

.subtitle {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-top: 4px;
}

.update-time {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* Main */
main {
  max-width: 1400px;
  margin: 0 auto;
  padding: 24px;
}

/* Stats Bar */
.stats-bar {
  display: flex;
  gap: 16px;
  margin-bottom: 24px;
}

.stat {
  flex: 1;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 24px;
  text-align: center;
}

.stat-value {
  display: block;
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent);
}

.stat-label {
  display: block;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* Controls */
.controls {
  margin-bottom: 24px;
}

.control-row {
  display: flex;
  gap: 12px;
  margin-bottom: 12px;
}

.search-box {
  flex: 1;
  padding: 10px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.95rem;
  background: var(--bg);
  color: var(--text);
  outline: none;
  transition: border-color 0.2s;
}

.search-box:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.filter-select {
  padding: 10px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg);
  color: var(--text);
  font-size: 0.95rem;
  min-width: 200px;
  outline: none;
  cursor: pointer;
}

.topic-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.topic-chip {
  padding: 4px 12px;
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: 0.8rem;
  cursor: pointer;
  background: var(--bg);
  color: var(--text-secondary);
  transition: all 0.2s;
  user-select: none;
  white-space: nowrap;
}

.topic-chip:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.topic-chip.active {
  background: var(--tag-bg);
  border-color: var(--accent);
  color: var(--tag-text);
}

/* Table */
.table-section {
  margin-bottom: 40px;
}

.table-wrapper {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

thead {
  background: var(--bg-secondary);
  position: sticky;
  top: 0;
}

th {
  padding: 12px 14px;
  text-align: left;
  font-weight: 600;
  color: var(--text-secondary);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  white-space: nowrap;
  border-bottom: 2px solid var(--border);
}

td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}

tr:hover {
  background: var(--bg-secondary);
}

.col-channel { min-width: 120px; }
.col-title { min-width: 250px; }
.col-date { min-width: 100px; white-space: nowrap; }
.col-views { min-width: 80px; text-align: right; }
.col-topics { min-width: 140px; }
.col-speaker { min-width: 100px; }
.col-level { min-width: 70px; }
.col-summary { min-width: 280px; }

.video-link {
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
}

.video-link:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

.views {
  text-align: right;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}

.tag {
  display: inline-block;
  padding: 2px 8px;
  background: var(--tag-bg);
  color: var(--tag-text);
  border-radius: 12px;
  font-size: 0.75rem;
  font-weight: 500;
  white-space: nowrap;
}

.level-badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 12px;
  font-size: 0.75rem;
  font-weight: 600;
  text-align: center;
}

.level-Beginner { background: #dcfce7; color: #166534; }
.level-Intermediate { background: #fef3c7; color: #92400e; }
.level-Advanced { background: #fce7f3; color: #9d174d; }

@media (prefers-color-scheme: dark) {
  .level-Beginner { background: #14532d; color: #86efac; }
  .level-Intermediate { background: #5c3d0e; color: #fcd34d; }
  .level-Advanced { background: #4a1942; color: #f9a8d4; }
}

.summary-text {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
  max-width: 320px;
}

.result-count {
  margin-top: 8px;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* Channel Relations */
.relations-section {
  margin-bottom: 40px;
  padding-top: 24px;
  border-top: 2px solid var(--border);
}

.relations-section h2 {
  font-size: 1.25rem;
  margin-bottom: 20px;
}

.focus-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 16px;
  margin-bottom: 32px;
}

.focus-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
}

.focus-card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.focus-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.focus-card .channel-topics {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-top: 10px;
}

.relations-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.relation-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 18px;
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

.relation-type {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 12px;
  font-size: 0.75rem;
  font-weight: 600;
  white-space: nowrap;
}

.relation-complementary { background: #dbeafe; color: #1e40af; }
.relation-contrasting { background: #fee2e2; color: #991b1b; }
.relation-referencing { background: #e0e7ff; color: #3730a3; }

@media (prefers-color-scheme: dark) {
  .relation-complementary { background: #1e3a5f; color: #93c5fd; }
  .relation-contrasting { background: #4a1d1d; color: #fca5a5; }
  .relation-referencing { background: #2e1065; color: #c4b5fd; }
}

.relation-text {
  flex: 1;
  font-size: 0.9rem;
}

.relation-overlap {
  font-size: 0.8rem;
  color: var(--text-secondary);
  white-space: nowrap;
}

/* Footer */
footer {
  text-align: center;
  padding: 24px;
  color: var(--text-secondary);
  font-size: 0.8rem;
  border-top: 1px solid var(--border);
}

/* Responsive */
@media (max-width: 768px) {
  .control-row {
    flex-direction: column;
  }

  .filter-select {
    min-width: 100%;
  }

  .focus-grid {
    grid-template-columns: 1fr;
  }

  .stats-bar {
    flex-direction: column;
  }

  header h1 {
    font-size: 1.25rem;
  }

  .table-wrapper {
    font-size: 0.8rem;
  }

  td, th {
    padding: 8px 10px;
  }
}

/* Loading / Empty States */
.empty-state {
  text-align: center;
  padding: 48px 24px;
  color: var(--text-secondary);
}

.empty-state p {
  font-size: 1.1rem;
}