.bigWrap{
    margin-bottom: 1.5rem;
}
.public-nav{
    display: -webkit-box;
    display: -moz-box;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-pack: justify;
       -moz-box-pack: justify;
        -ms-flex-pack: justify;
            justify-content: space-between;
    position: fixed;
    z-index: 10;
    bottom: 0;
        left: 0;
    width: 100%;
    background-color: #f8f8f8;
    text-align: center;
}
.public-nav li span {
    display: block;
    margin-bottom:8px;  
}
.public-nav li.active span {
    color: #ff6b6f;
}

.public-nav li {
    width: 25%;

}
.public-nav li a{
    
    width: 100%;
    height: 100%;
    font-size: 24px;
    color: #333;
    -webkit-box-sizing: border-box;
       -moz-box-sizing: border-box;
            box-sizing: border-box;
}

.public-nav li a img{
    margin-top:8px;  
    height:18px;
    margin-bottom: 8px;
}


 /* 400 以下   400  -  480 一档  480 以上的是一档  */
 @media screen and (max-width:399px) {
    .public-nav li a img{
        height:18px;
        margin-bottom: 6px;
    }
    .public-nav li a{
        font-size: 12px;
    }
 }
 @media (min-width: 400px) and (max-width: 480px) {
    .public-nav li a img{
        height:23px;
        margin-bottom: 8px;
    }
    .public-nav li a{
        font-size: 14px;
    }
 }
 @media screen and (min-width: 481px) {
    .public-nav li a img{
        height:40px;
        margin-bottom: 16px;
    }
    .public-nav li a{
        font-size: 25px;    /* 最大档 */
    }
 }