.wrapper{
    /* 60%窗口宽度 */
    width: 12rem;
    /* height: 60px; */
    line-height: .7rem;
    background-color: #fff;
    /* 盒子阴影 */
    box-shadow: 0px 5px 15px rgba(0,0,0,0.25);
    border-radius: .5rem;
    margin-top: 0;
    background-color: #EEF5FE;
}
.wrapper nav{
    display: flex;
    position: relative;
}
.wrapper nav label{
    flex:1;
    width: 100%;
    position: relative;
    z-index: 1;
    cursor: pointer;
    text-align: center;
    margin-top: -.2rem;

}
.wrapper nav label a{
    position: relative;
    z-index: -1;
    color: #918E96;
    font-size: 20px;
    font-weight: 500;
    text-decoration: none;
    pointer-events: none;
}
.wrapper nav label a i{
    font-size: 25px;
    margin: 0px 7px;
}
.wrapper nav .tab{
    position: absolute;
    height: 100%;
    width: 16.6%;
    left: 0px;
    bottom: 0px;
    /* 渐变背景 自左向右 */
    background: linear-gradient(to left, #3069F3, #5B9AF5);
    border-radius: .5rem;
    /* 动画过渡 贝塞尔曲线 */
    transition: 0.6s cubic-bezier(0.68,-0.55,0.265,1.55);
}
.wrapper nav input{
    display: none;
}
.wrapper nav #home:checked ~ label.home a,
.wrapper nav #comment:checked ~ label.comment a,
.wrapper nav #envelope:checked ~ label.envelope a,
.wrapper nav #heart:checked ~ label.heart a,
.wrapper nav #user:checked ~ label.user a,
.wrapper nav #my:checked ~ label.my a{
    color: #fff;
    transition: 0.6s;
}

.wrapper nav #comment:checked ~ .tab{
    left: 16.6%;
}
.wrapper nav #envelope:checked ~ .tab{
    left: 33.2%;
}
.wrapper nav #heart:checked ~ .tab{
    left: 49.8%;
}
.wrapper nav #user:checked ~ .tab{
    left: 66.4%;
}
.wrapper nav #my:checked ~ .tab{
    left: 83.4%;
}