css实现点点点效果

      @keyframes dotDotDoting{
        0%
{
          width 0px
          margin-right 15px
}

        25%
{
          width 0px
          margin-right 15px
}

        50%
{
          width 5px
          margin-right 10px
}

        75%
{
          width 10px
          margin-right 5px
}

        100%
{
          width 15px
          margin-right 0
}
        }

      &.dot::after
{
        content '...'
        display inline-block
        vertical-align bottom
        overflow hidden
        width 15px
        animation dotDotDoting 1.2s infinite step-start
}