Pure-CSS-Loading-Effect.css

.loading-anim{
  font-size: 16px;
  display: inline-block;
  &:after{
    content: "\2026";
    font-family: "Simsun";
    overflow: hidden;
    display: inline-block;
    vertical-align: bottom;
    animation: loading-anim 1.2s infinite;
  }
}

@keyframes loading-anim{
  0%, 25%{
    width: 0;
  }
  26%, 50%{
    width: 0.333em;
  }
  51%, 75%{
    width: 0.666em;
  }
  76%, 100%{
    width: 1em;
  }
}