:root {
  --green: #2e7d32;
  --bg: #f2fbf2;
  --card: #ffffff;
  --ink: #223;
  --muted: #6b6b6b;
  --accent: #66bb6a;
}
* {
  box-sizing: border-box;
}
body {
  margin: 0;
  font-family: system-ui, Segoe UI, Roboto, Arial;
  background: var(--bg);
  color: var(--ink);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  align-items: center;
}
header {
  width: 100%;
  background: var(--green);
  color: #fff;
  padding: 14px 18px;
  text-align: center;
  font-weight: 700;
  font-size: clamp(18px, 2.8vw, 22px);
  position: sticky;
  top: 0;
  z-index: 20;
}

.games-grid {
  width: min(1100px, 96%);
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  margin: 18px auto;
}
.game-card {
  background: var(--card);
  padding: 14px;
  border-radius: 12px;
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.06);
  cursor: pointer;
  user-select: none;
  border: 1px solid rgba(46, 125, 50, 0.06);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  text-align: center;
}
.game-card h3 {
  margin: 6px 0 4px;
  font-size: 16px;
}
.game-card p {
  margin: 0;
  font-size: 13px;
  color: var(--muted);
}
.game-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 14px 30px rgba(0, 0, 0, 0.08);
}

#game-container {
  width: min(1100px, 96%);
  background: var(--card);
  border-radius: 14px;
  box-shadow: 0 14px 30px rgba(0, 0, 0, 0.08);
  margin: 10px auto 32px;
  overflow: hidden;
  display: none;
}

.topbar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  background: #f6fff6;
  border-bottom: 1px solid #e7f5e7;
  flex-wrap: wrap;
}
.back-btn {
  background: var(--green);
  color: #fff;
  border: 0;
  padding: 8px 12px;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 700;
}
.stat {
  background: #fff;
  padding: 8px 12px;
  border-radius: 10px;
  border: 1px solid #e9f6ea;
  font-weight: 600;
}
.btn {
  appearance: none;
  border: 1px solid #e7f5e7;
  background: white;
  padding: 8px 10px;
  border-radius: 8px;
  cursor: pointer;
}
.btn.primary {
  background: var(--accent);
  color: white;
  border-color: var(--accent);
}
.panel {
  padding: 16px;
  min-height: 420px;
}
canvas {
  display: block;
  margin: 12px auto;
  max-width: 100%;
  height: auto;
  border-radius: 10px;
  background: #eafbe7;
  border: 2px solid var(--green);
}

/* grid helpers */
.row {
  display: flex;
  gap: 12px;
  align-items: center;
  flex-wrap: wrap;
}
.grid {
  display: grid;
  gap: 12px;
}

/* memory / match board */
.board {
  display: grid;
  gap: 10px;
  justify-content: center;
  margin: 18px auto;
}
.card {
  background: #eafbe7;
  border: 2px solid var(--green);
  border-radius: 10px;
  aspect-ratio: 1/1;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  cursor: pointer;
  user-select: none;
}
.card.open {
  background: #fff;
}
.card.matched {
  background: #d7ffd7;
  opacity: 0.95;
  cursor: default;
}

/* sliding puzzle */
.puzzle {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 6px;
  width: min(360px, 90%);
  margin: 12px auto;
}
.tile {
  aspect-ratio: 1/1;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  font-size: 28px;
  background: #eafbe7;
  border: 2px solid var(--green);
  cursor: pointer;
}
.tile.blank {
  background: transparent;
  border: 2px dashed #bfecc0;
  cursor: default;
}

/* trash sorter */
.bins {
  display: flex;
  gap: 12px;
  justify-content: center;
  margin: 12px auto;
  flex-wrap: wrap;
}
.bin {
  width: 120px;
  height: 120px;
  border-radius: 10px;
  border: 2px solid #d9f2d9;
  background: #f7fff7;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 8px;
  color: var(--muted);
}
.trash-pile {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: center;
  padding: 10px;
  border-radius: 10px;
  margin-top: 12px;
}

/* mobile controls */
.mobile-controls {
  display: none;
  gap: 10px;
  justify-content: center;
  margin-top: 8px;
}
.mobile-controls button {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  border: 0;
  background: var(--green);
  color: #fff;
  font-size: 20px;
  box-shadow: 0 6px 14px rgba(0, 0, 0, 0.12);
  cursor: pointer;
}
@media (max-width: 820px) {
  .mobile-controls {
    display: flex;
  }
  .panel {
    padding: 12px;
  }
  .game-card h3 {
    font-size: 15px;
  }
}

footer {
  margin-bottom: 22px;
  color: var(--muted);
  font-size: 13px;
}
header .back-btn {
  background: #fff;
  color: var(--green);
  padding: 6px 12px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  display: inline-block;
  margin-right: 12px;
}
header .back-btn:hover {
  background: var(--accent);
  color: #fff;
}