/* ===== 关键帧动画 ===== */
@keyframes popIn {
  0% { transform: scale(0); opacity: 0; }
  70% { transform: scale(1.1); }
  100% { transform: scale(1); opacity: 1; }
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
  40% { transform: translateX(-50%) translateY(-10px); }
  60% { transform: translateX(-50%) translateY(-5px); }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-5px); }
  50% { transform: translateX(5px); }
  75% { transform: translateX(-5px); }
}

@keyframes floatChar {
  0% { transform: translateY(100vh) rotate(0deg); opacity: 0; }
  10% { opacity: 0.08; }
  90% { opacity: 0.08; }
  100% { transform: translateY(-10vh) rotate(360deg); opacity: 0; }
}

/* ===== 滚动动画 ===== */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.6s ease-out;
}
.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

.fade-in-left {
  opacity: 0;
  transform: translateX(-30px);
  transition: all 0.6s ease-out;
}
.fade-in-left.visible {
  opacity: 1;
  transform: translateX(0);
}

.fade-in-right {
  opacity: 0;
  transform: translateX(30px);
  transition: all 0.6s ease-out;
}
.fade-in-right.visible {
  opacity: 1;
  transform: translateX(0);
}

/* Hero 背景漂浮字符 */
.hero-bg {
  position: absolute; inset: 0;
  overflow: hidden; pointer-events: none;
}
.hero-bg .char {
  position: absolute;
  font-size: 3rem;
  opacity: 0;
  animation: floatChar 20s infinite linear;
  color: var(--clay);
}

/* 高亮文字弹出 */
.highlight {
  display: inline-block;
  animation: popIn 0.6s ease-out;
}

/* 滚动指示器 */
.scroll-indicator {
  position: absolute; bottom: 30px; left: 50%;
  transform: translateX(-50%);
  animation: bounce 2s infinite;
  color: var(--clay); font-size: 1.5rem; cursor: pointer;
}