/* games/memory-card/style.css */

.difficulty-bar {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 16px;
}

/* ── 棋盤：perspective 必須在"父層"才能讓子元素 3D 翻轉生效 ── */
.memory-board {
  --cols: 4;
  display: grid;
  grid-template-columns: repeat(var(--cols), 1fr);
  gap: 10px;
  max-width: 600px;
  width: 100%;
  perspective: 1000px;   /* ← 移到父層 */
}

/* ── 卡片本體：翻轉整張牌 ── */
.memory-card {
  aspect-ratio: 1;
  border-radius: var(--border-radius);
  border: 3px solid var(--color-border);
  background: transparent;          /* 透明，讓兩面的背景各自顯示 */
  font-size: clamp(24px, 6vw, 52px);
  cursor: pointer;
  position: relative;
  transform-style: preserve-3d;     /* 子元素套用 3D 空間 */
  transition: transform 0.45s ease; /* 整張牌翻面 */
  font-family: inherit;
  padding: 0;
  /* ↑ 不設 overflow:hidden — 3D 旋轉時會被錯誤裁切 */
}

.memory-card:hover:not(.matched):not(.flipped) {
  transform: scale(1.06);
}

/* 翻開時整張牌旋轉 180° */
.memory-card.flipped,
.memory-card.matched {
  transform: rotateY(180deg);
}

/* 配對成功額外樣式 */
.memory-card.matched {
  border-color: var(--color-success);
  cursor: default;
}

/* ── 牌的兩面：共同屬性 ── */
.memory-card .card-front,
.memory-card .card-back {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 9px;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden; /* Safari */
}

/* 背面（？）：預設朝向玩家，旋轉 0° */
.memory-card .card-back {
  background: linear-gradient(135deg, #D4380D 0%, #FA8C16 100%);
  color: #fff;
  font-size: 1.4em;
  font-weight: 700;
  transform: rotateY(0deg);
}

/* 正面（emoji）：預設背對玩家，旋轉 180° */
.memory-card .card-front {
  background: #fff;
  transform: rotateY(180deg);
}

/* 配對成功正面 */
.memory-card.matched .card-front {
  background: #f6ffed;
}

@media (max-width: 480px) {
  .memory-board { gap: 6px; perspective: 600px; }
  .memory-card { border-width: 2px; }
}