:root {
  --bg: #14171c;
  --panel: #1b1f26;
  --divider: #2a2f38;
  --text: #edebe4;
  --text-dim: #888e96;
  --amber: #f2a33c;
  --live: #4fc1e0;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Noto Sans SC", sans-serif;
}

.mono {
  font-family: "JetBrains Mono", monospace;
}

.dim {
  color: var(--text-dim);
}

a {
  color: inherit;
  text-decoration: none;
}

/* ---------- header ---------- */

.board-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 24px;
  border-bottom: 1px solid var(--divider);
  flex-wrap: wrap;
}

.board-header-left {
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.board-header-left h1 {
  font-size: 22px;
  font-weight: 700;
  margin: 0;
  letter-spacing: 0.02em;
}

.board-sub {
  font-family: "JetBrains Mono", monospace;
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--text-dim);
}

.live-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--live);
  box-shadow: 0 0 0 0 rgba(79, 193, 224, 0.6);
  animation: pulse 2s ease-out infinite;
}

@media (prefers-reduced-motion: reduce) {
  .live-dot {
    animation: none;
  }
}

@keyframes pulse {
  0% {
    box-shadow: 0 0 0 0 rgba(79, 193, 224, 0.5);
  }
  70% {
    box-shadow: 0 0 0 6px rgba(79, 193, 224, 0);
  }
  100% {
    box-shadow: 0 0 0 0 rgba(79, 193, 224, 0);
  }
}

.board-header-right {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 12px;
}

.board-btn {
  background: transparent;
  border: 1px solid var(--divider);
  color: var(--text);
  padding: 6px 14px;
  border-radius: 4px;
  font-size: 12px;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
}

.board-btn:hover {
  border-color: var(--amber);
  color: var(--amber);
}

.board-btn:focus-visible,
.tab:focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: 2px;
}

/* ---------- tabs ---------- */

.tabs {
  display: flex;
  gap: 4px;
  padding: 12px 24px 0;
  flex-wrap: wrap;
}

.tab {
  background: transparent;
  border: none;
  color: var(--text-dim);
  font-size: 13px;
  padding: 8px 14px;
  cursor: pointer;
  border-bottom: 2px solid transparent;
  letter-spacing: 0.03em;
}

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

.tab.active {
  color: var(--amber);
  border-bottom-color: var(--amber);
}

/* ---------- board ---------- */

.board {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 16px;
  padding: 20px 24px 8px;
}

.board.single {
  grid-template-columns: 1fr;
  max-width: 720px;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--divider);
  border-radius: 6px;
  overflow: hidden;
}

.panel.is-hidden {
  display: none;
}

.panel-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 16px;
  border-bottom: 1px solid var(--divider);
  font-size: 12px;
  letter-spacing: 0.05em;
}

.panel-head .name {
  font-weight: 500;
  color: var(--text);
}

.panel-head .code {
  color: var(--amber);
}

.item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 16px;
  border-bottom: 1px solid var(--divider);
  opacity: 0;
  animation: flap-in 0.3s ease forwards;
}

.item:last-child {
  border-bottom: none;
}

@media (prefers-reduced-motion: reduce) {
  .item {
    opacity: 1;
    animation: none;
  }
}

@keyframes flap-in {
  from {
    opacity: 0;
    transform: translateY(-4px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.item .rank {
  flex: 0 0 28px;
  text-align: center;
  font-size: 12px;
  font-weight: 700;
  color: var(--text-dim);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--divider);
  border-radius: 4px;
  padding: 3px 0;
}

.item .rank.top {
  color: var(--amber);
  border-color: var(--amber);
}

.item .title {
  flex: 1;
  font-size: 14px;
  line-height: 1.4;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

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

.item .hot {
  flex: 0 0 auto;
  font-size: 11px;
  color: var(--text-dim);
}

.empty,
.error {
  padding: 24px 16px;
  font-size: 13px;
  color: var(--text-dim);
  text-align: center;
}

.error {
  color: var(--amber);
}

/* ---------- footer ---------- */

.board-footer {
  padding: 24px;
  font-size: 11px;
  text-align: center;
  letter-spacing: 0.03em;
}

@media (max-width: 600px) {
  .board-header {
    padding: 16px;
  }
  .tabs {
    padding: 12px 16px 0;
  }
  .board {
    padding: 16px 16px 8px;
    grid-template-columns: 1fr;
  }
}