:root {
  color-scheme: light dark;
  --bg: #f8fafc;
  --text: #0f172a;
  --muted: #64748b;
  --card: #ffffff;
  --border: #e2e8f0;
  --shadow: 0 16px 32px rgba(15, 23, 42, 0.12);
  --board-light: #e2e8f0;
  --board-dark: #475569;
  --red: #dc2626;
  --yellow: #facc15;
  --ring: #f97316;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f172a;
    --text: #f8fafc;
    --muted: #94a3b8;
    --card: #111827;
    --border: #1e293b;
    --shadow: 0 16px 32px rgba(0, 0, 0, 0.35);
    --board-light: #1f2937;
    --board-dark: #475569;
    --red: #f87171;
    --yellow: #fde047;
    --ring: #f59e0b;
  }
}

body {
  background: var(--bg);
  color: var(--text);
}

.checkers-page {
  max-width: 1100px;
  margin: 0 auto;
  padding: 72px 16px 48px;
}

.checkers-hero {
  display: flex;
  flex-direction: column;
  gap: 20px;
  margin-bottom: 24px;
}

.hero-text h1 {
  font-size: clamp(32px, 4vw, 44px);
  margin-bottom: 8px;
}

.subtitle {
  color: var(--muted);
  max-width: 620px;
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.2em;
  font-size: 12px;
  font-weight: 700;
  color: var(--muted);
}

.hero-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.hero-badges span {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 6px 12px;
  font-size: 12px;
  font-weight: 600;
  box-shadow: var(--shadow);
}

.ad-slot {
  border: 2px dashed var(--border);
  border-radius: 16px;
  padding: 18px;
  text-align: center;
  color: var(--muted);
  background: var(--card);
  margin: 20px 0;
}

.checkers-game {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr);
  gap: 24px;
  align-items: start;
}

.board-panel {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 20px;
  box-shadow: var(--shadow);
}

.status-bar {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 16px;
}

.status {
  font-weight: 600;
  color: var(--text);
}

.action-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.action {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 16px;
  background: var(--card);
  color: var(--text);
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.1s ease, box-shadow 0.2s ease;
}

.action.primary {
  background: var(--ring);
  border-color: transparent;
  color: #0f172a;
}

.action:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  box-shadow: none;
}

.action:not(:disabled):hover {
  transform: translateY(-1px);
  box-shadow: 0 8px 18px rgba(15, 23, 42, 0.2);
}

.board-wrapper {
  width: 100%;
  display: flex;
  justify-content: center;
}

.board {
  width: min(100%, 560px);
  aspect-ratio: 1 / 1;
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  border-radius: 16px;
  overflow: hidden;
  border: 2px solid var(--border);
  box-shadow: var(--shadow);
  background: var(--board-light);
}

.square {
  border: none;
  padding: 0;
  margin: 0;
  background: transparent;
  position: relative;
  cursor: pointer;
}

.square.dark {
  background: var(--board-dark);
}

.square.light {
  background: var(--board-light);
}

.square.selected {
  outline: 3px solid var(--ring);
  outline-offset: -3px;
}

.square.hint::after {
  content: "";
  position: absolute;
  inset: 28%;
  border-radius: 50%;
  background: rgba(248, 113, 113, 0.8);
}

.square.capture-hint::after {
  content: "";
  position: absolute;
  inset: 18%;
  border: 3px solid rgba(248, 113, 113, 0.8);
  border-radius: 50%;
  background: transparent;
}

.piece {
  width: 70%;
  height: 70%;
  border-radius: 50%;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  display: grid;
  place-items: center;
  box-shadow: inset 0 4px 6px rgba(255, 255, 255, 0.35), inset 0 -6px 8px rgba(0, 0, 0, 0.25);
}

.piece.red {
  background: var(--red);
}

.piece.yellow {
  background: var(--yellow);
}

.king-badge {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: rgba(15, 23, 42, 0.85);
  color: #fff;
  display: grid;
  place-items: center;
  font-size: 12px;
  font-weight: 700;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
}

.side-panel {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.panel-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 18px;
  box-shadow: var(--shadow);
}

.panel-card h2,
.panel-card h3 {
  margin-bottom: 10px;
}

.panel-card ul {
  padding-left: 18px;
  color: var(--muted);
  display: grid;
  gap: 8px;
}

.panel-card p {
  color: var(--muted);
}

.seo-block {
  margin: 32px 0 20px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 20px;
  box-shadow: var(--shadow);
}

.seo-block p {
  color: var(--muted);
}

.site-footer {
  text-align: center;
  padding: 24px 16px 32px;
  color: var(--muted);
}

.site-footer a {
  color: inherit;
}

@media (max-width: 900px) {
  .checkers-game {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 600px) {
  .checkers-page {
    padding-top: 64px;
  }

  .board-panel {
    padding: 16px;
  }

  .action-row {
    flex-direction: column;
  }
}