@media screen and (max-width:321px){
    body{
        font-size:16px;
    }
    #foot_nav{
        font-size: 14px;
    }
}
@media screen and (min-width: 321px) and (max-width:400px){
    body{
        font-size:17px;
    }
    #foot_nav{
        font-size: 16px;
    }
}
@media screen and (min-width:400px)and (max-width:600px){
    body{
        font-size:19px;
    }
    #foot_nav{
        font-size: 16px;
    }
}
@media screen and (min-width:600px){
    body{
        font-size:22px;
    }
    #foot_nav{
        font-size: 18px;
    }
}
#foot_nav{
    text-align: center;
    background-color: #fff;
    position: fixed;
    bottom: 0;
    width:100%;
    height:1.5rem;
    z-index: 10;
    list-style: none;
    padding-top: 0.2rem;
    vertical-align: middle;
}
#foot_nav>li{
    display: inline-block;
    margin-right: 0.2rem;
    width:1.4rem;
    vertical-align: top;
}
#foot_nav>li:last-child{
    margin-right: 0;
}
#foot_nav p{
    text-align: center;
}
#foot_nav img{
    width:0.6rem;
    height:0.6rem;
}
#foot_nav li:first-child{
    width:1rem
}