修复浮动导致的高度坍塌问题

@mixin clearfix {
  &:after {
    clear: both;
    content: '.';
    display: block;
    height: 0;
    line-height: 0;
    overflow: hidden;
  }
  *height: 1%;
}

单行文本超长显示省略号

@mixin textOverflow($width:100%,$display:block) {
  max-width: $width;
  display: $display;
  white-space: nowrap;
  -ms-text-overflow: ellipsis;
  text-overflow: ellipsis;
  overflow: hidden;
}