SOURCE

<div class="box">
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</div>

.box {
  /* width: 100px; */
  border: 1px solid;
  
  /* 方法一： */
  /* display: -webkit-box;
  -webkit-box-orient: vertical;
  overflow: hidden;
  -webkit-line-clamp: 3; */
  
  /* 方法二： */
  /* padding-right: 1em;
  position: relative;
  line-height: 1.2em;
  max-height: 3.6em;
  text-align: justify;
  overflow: hidden;
  &:before {
    content: '...';
    position: absolute;
    right: 0;
    bottom: 0;
  }
  &:after {
    content: '';
    position: absolute;
    right: 0;
    width: 1em;
    height: 1.2em;
    background: #fff;
    z-index: 10;
  } */
  
  /* 方法三 */
  /*需要定高*/
    height: 100px;
    line-height: 25px;
    text-align: justify;
    overflow: hidden;
    background: #fff;
    &:before {
      float: left;
      width: 1em;
      height: 100%;
      content: ''; 
    }
    &:after {
      float: right;
      width: 2.5em;
      height: 25px;
      margin-left: -2.5em;
      padding-right: 1em;
      content: '...';
      text-align: right;
      position: relative;
      top: -25px;
      left: 100%;
      background: #fff;
      background: -webkit-gradient(linear, left top, right top, from(rgba(255, 255, 255, 0)), to(white), color-stop(50%, white));
      background: -moz-linear-gradient(to right, rgba(255, 255, 255, 0), white 50%, white);
      background: -o-linear-gradient(to right, rgba(255, 255, 255, 0), white 50%, white);
      background: -ms-linear-gradient(to right, rgba(255, 255, 255, 0), white 50%, white);
      background: linear-gradient(to right, rgba(255, 255, 255, 0), white 50%, white);
    }
    &_text {
      float: right;
      margin-left: -1em;
      width: 100%;
    } 
}