:root {
  --bg: #0f1221;
  --bg-2: #171b31;
  --card: #1e2440;
  --card-hover: #2a3358;
  --text: #f2f4ff;
  --muted: #9aa3c7;
  --accent: #7c5cff;
  --accent-2: #22d3ee;
  --success: #34d399;
  --danger: #f87171;
  --warning: #fbbf24;
  --border: rgba(255, 255, 255, 0.08);
  --shadow: 0 12px 40px rgba(0, 0, 0, 0.35);
  --radius: 16px;
  --font: "Segoe UI", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  min-height: 100%;
  font-family: var(--font);
  color: var(--text);
  background:
    radial-gradient(1200px 600px at 10% -10%, rgba(124, 92, 255, 0.25), transparent 60%),
    radial-gradient(900px 500px at 100% 0%, rgba(34, 211, 238, 0.18), transparent 55%),
    var(--bg);
  -webkit-tap-highlight-color: transparent;
  user-select: none;
}

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

.page {
  max-width: 1100px;
  margin: 0 auto;
  padding: 24px 16px 48px;
}

.site-header {
  text-align: center;
  margin-bottom: 28px;
}

.site-header h1 {
  margin: 0 0 8px;
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  letter-spacing: 0.02em;
}

.subtitle {
  margin: 0;
  color: var(--muted);
  font-size: 1rem;
}

.game-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 16px;
}

.game-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px 18px;
  background: linear-gradient(160deg, var(--card), var(--bg-2));
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform 0.18s ease, background 0.18s ease, border-color 0.18s ease;
  cursor: pointer;
}

.game-card:hover,
.game-card:focus-visible {
  transform: translateY(-4px);
  background: linear-gradient(160deg, var(--card-hover), var(--card));
  border-color: rgba(124, 92, 255, 0.45);
  outline: none;
}

.game-card .emoji {
  font-size: 2.4rem;
  line-height: 1;
}

.game-card h2 {
  margin: 0;
  font-size: 1.15rem;
}

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

.site-footer {
  margin-top: 36px;
  text-align: center;
  color: var(--muted);
  font-size: 0.85rem;
}

/* Game shell */
.game-page {
  max-width: 720px;
  margin: 0 auto;
  padding: 16px 14px 40px;
}

.game-top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 14px;
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.9rem;
  transition: background 0.15s, color 0.15s;
}

.back-link:hover {
  background: rgba(255, 255, 255, 0.1);
  color: var(--text);
}

.game-title-block h1 {
  margin: 0 0 4px;
  font-size: clamp(1.35rem, 3vw, 1.8rem);
}

.howto {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.45;
}

.hud {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  margin: 14px 0;
}

.stat {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border);
  font-size: 0.92rem;
}

.stat strong {
  color: var(--accent-2);
  font-variant-numeric: tabular-nums;
}

.btn {
  appearance: none;
  border: none;
  cursor: pointer;
  font: inherit;
  padding: 10px 18px;
  border-radius: 12px;
  font-weight: 600;
  transition: transform 0.12s, filter 0.12s, background 0.12s;
}

.btn:active {
  transform: scale(0.97);
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), #5b8cff);
  color: #fff;
}

.btn-primary:hover {
  filter: brightness(1.08);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.12);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.stage {
  position: relative;
  margin: 0 auto;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
  touch-action: none;
}

.stage canvas {
  display: block;
  width: 100%;
  height: auto;
  cursor: crosshair;
}

.overlay {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  background: rgba(10, 12, 24, 0.78);
  backdrop-filter: blur(4px);
  text-align: center;
  padding: 20px;
  z-index: 5;
}

.overlay.hidden {
  display: none;
}

.overlay h2 {
  margin: 0;
  font-size: 1.6rem;
}

.overlay p {
  margin: 0;
  color: var(--muted);
}

.empty-state {
  text-align: center;
  padding: 48px 16px;
}

.empty-state p {
  color: var(--muted);
  margin-bottom: 18px;
}

/* Memory / puzzle / minesweeper DOM boards */
.board {
  display: grid;
  gap: 8px;
  padding: 12px;
  width: 100%;
  max-width: 480px;
  margin: 0 auto;
}

.cell, .tile, .card-face {
  aspect-ratio: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  font-weight: 700;
  cursor: pointer;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
  font-size: clamp(1rem, 4vw, 1.4rem);
  transition: transform 0.1s, background 0.15s;
}

.cell:active, .tile:active, .card-face:active {
  transform: scale(0.96);
}

.arrow-pad {
  display: grid;
  grid-template-columns: repeat(3, 56px);
  gap: 8px;
  justify-content: center;
  margin-top: 14px;
}

.arrow-pad .btn {
  width: 56px;
  height: 56px;
  padding: 0;
  font-size: 1.3rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.arrow-pad .spacer {
  visibility: hidden;
}

@media (max-width: 520px) {
  .game-page { padding: 12px 10px 32px; }
  .hud { gap: 8px; }
  .stat { font-size: 0.82rem; padding: 6px 10px; }
}