css 伪类返回箭头

css 伪类返回箭头

    .arrow:before {
            content: " ";
    display: inline-block;
    -webkit-transform: rotate(45deg);
    -ms-transform: rotate(45deg);
    transform: rotate(45deg);
    height: .5rem;
    width: .5rem;
    border-width: 0 0 2px 2px;
    border-color: #666;
    border-style: solid;
    position: relative;
    top: 0
    }