问微信小程序如何实现底部菜单表？

div.cn {

    position: relative;

    width: 200px;

    height: 200px;

    background: gray;

    text-align: center;

}

div.inner {

    position: absolute;

    top: 50%;

    left: 50%;

    width: 100px;

    height: 100px;

    -webkit-transform: translate(-50%, -50%);  

    transform: translate(-50%, -50%);   

    background: red;

}

<div class="cn">

    <div class="inner">

        test

    </div>

</div>

.Absolute-Center {

  margin: auto;

  position: absolute;

  top: 0; left: 0; bottom: 0; right: 0;

}