Pure CSS multiline ellipsis (CSS + SCSS)

.css

/* styles for '...' */ 
.block-with-text {
  /* hide text if it more than N lines  */
  overflow: hidden;
  /* for set '...' in absolute position */
  position: relative; 
  /* use this value to count block height */
  line-height: 1.2em;
  /* max-height = line-height (1.2) * lines max number (3) */
  max-height: 3.6em; 
  /* fix problem when last visible word doesn't adjoin right side  */
  text-align: justify;  
  /* place for '...' */
  margin-right: -1em;
  padding-right: 1em;
}
/* create the ... */
.block-with-text:before {
  /* points in the end */
  content: '...';
  /* absolute position */
  position: absolute;
  /* set position to right bottom corner of block */
  right: 0;
  bottom: 0;
}
/* hide ... if we have text, which is less than or equal to max lines */
.block-with-text:after {
  /* points in the end */
  content: '';
  /* absolute position */
  position: absolute;
  /* set position to right bottom corner of text */
  right: 0;
  /* set width and height */
  width: 1em;
  height: 1em;
  margin-top: 0.2em;
  /* bg color = bg color under block */
  background: white;
}

scss

@mixin multiLineEllipsis($lineHeight: 1.2em, $lineCount: 1, $bgColor: white){
  overflow: hidden;
  position: relative;
  line-height: $lineHeight;
  max-height: $lineHeight * $lineCount; 
  text-align: justify;
  margin-right: -1em;
  padding-right: 1em;
  &:before {
    content: '...';
    position: absolute;
    right: 0;
    bottom: 0;
  }
  &:after {
    content: '';
    position: absolute;
    right: 0;
    width: 1em;
    height: 1em;
    margin-top: 0.2em;
    background: $bgColor;
  }
}
// Example usage
.block-with-text {
  @include multiLineEllipsis($lineHeight: 1.2em, $lineCount: 3, $bgColor: white);  
}