.com-sel {
    line-height: 5rem;
    cursor: pointer;        /*鼠标上移变成小手*/
}

.com-opt {
    padding-right: 1.8rem;
    border: none;
    outline: none;
    /*去掉默认的下拉三角
    appearance:none;
    -moz-appearance:none;
    -webkit-appearance:none;*/
    /*添加下拉三角图标
    background: url("/images/select.jpg") no-repeat right center transparent;*/
}