标签横线伸展开动画

.baseline {
    
    
  width: 100%;
  height: 5rpx;
  border-radius: 10rpx;
  background: #16BA98;
  animation: underFadeIn .3s;
}

@keyframes underFadeIn {
    
    
  0% {
    
    
    width: 0;
    left: 50%;
  }

  100% {
    
    
    width: 100%;
    left: 0;
  }
}