.outer {
    position: relative;
    /*margin: 20px auto;*/
    width: 215px;
    height: 30px;
    line-height: 28px;
    border: 1px solid #ccc;
    /*background: #ccc9c9;*/
    background: #fff;
    /*background:#f78d42;*/
    font-size: 12px;    
    margin:auto; 
    float:left;
} 

    .outer span, .filter-box, .inner {
        position: absolute;
        top: 0;
        left: 0;
    }

    .outer span {
        display: block;
        padding: 0 0 0 36px;
        width: 100%;
        height: 100%;
        color: #000;
        text-align: center;
    }


.filter-box {
    width: 0;
    height: 100%;
    background:#5e7ffc;
    z-index: 9;
}

.outer.act span {
    padding: 0 36px 0 0;
    color: #fff;
}

.inner {
    width: 36px;
    height: 28px;
    text-align: center;
    background: #fff;
    background: #ccc9c9;
    cursor: pointer;
    font-family: "宋体";
    z-index: 10;
    font-weight: bold;
    color: #929292;
}

.outer.act .inner {
    color: green;
}

.outer.act span {
    z-index: 99;
}