.beian{
    background-color: #fff;
    padding-bottom: 10px;
    text-align: center;
}
.beian a{
    color: #bbb;
    text-decoration:none;
}
.beian a:hover{
    text-decoration: underline;
}

@media screen and (max-width: 500px) {
    .beian{
        text-align: center;
    }
    .beian a {
        display: block;
    }
}