/* 全局与细节增强样式 */
@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700;800&family=Noto+Sans+SC:wght@400;500;700;900&display=swap');

body {
  font-family: 'Plus Jakarta Sans', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  letter-spacing: -0.01em;
}

/* 单词卡片样式 (模拟游戏立体卡片效果) */
.word-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.5rem 0.875rem;
  background-color: #ffffff;
  color: #1e293b;
  font-size: 0.875rem;
  font-weight: 700;
  border-radius: 0.75rem;
  border: 1.5px solid #e2e8f0;
  box-shadow: 0 3px 0 0 #cbd5e1;
  cursor: pointer;
  user-select: none;
  transition: all 0.15s ease-out;
}

.word-btn:hover {
  background-color: #f8fafc;
  border-color: #94a3b8;
  transform: translateY(-1px);
  box-shadow: 0 4px 0 0 #94a3b8;
}

.word-btn:active {
  transform: translateY(2px);
  box-shadow: 0 1px 0 0 #94a3b8;
}

/* 单词已被选中使用状态 */
.word-btn.selected {
  opacity: 0.35;
  pointer-events: none;
  filter: grayscale(1);
  transform: translateY(2px);
  box-shadow: 0 1px 0 0 #e2e8f0;
}

/* 放置在目标槽里的已拼单词卡片 */
.puzzle-slot-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.45rem 0.8rem;
  background-color: #3b82f6;
  color: #ffffff;
  font-size: 0.875rem;
  font-weight: 700;
  border-radius: 0.75rem;
  border: 1.5px solid #2563eb;
  box-shadow: 0 3px 0 0 #1d4ed8;
  cursor: pointer;
  user-select: none;
  transition: all 0.15s ease-out;
  animation: popIn 0.2s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.puzzle-slot-btn:hover {
  background-color: #ef4444;
  border-color: #dc2626;
  box-shadow: 0 3px 0 0 #b91c1c;
}

.puzzle-slot-btn:hover::after {
  content: ' ✕';
  font-size: 0.75rem;
  margin-left: 0.25rem;
}

@keyframes popIn {
  0% {
    opacity: 0;
    transform: scale(0.85);
  }
  100% {
    opacity: 1;
    transform: scale(1);
  }
}