/* 涟漪扩散效果 */
@keyframes rippleDot {
  0% {
    transform: translate(-50%, -50%) scale(0.5);
    opacity: 1;
  }
  30% {
    opacity: 1;
  }
  100% {
    transform: translate(-50%, -50%) scale(1.4);
    opacity: 0;
  }
}