.nathan_center {
    text-align: center;
}

.logo-header>img {
    margin: 100px 0;
    width: 210px;
    height: 36px;
}

.site-content {
    margin: 0 20%;
    width: 60%;
}

.auth-nav>a {
    margin-right: 5px;
}

.layui-layer-btn a {
    box-sizing: content-box;
}

@media (max-width: 769px) {
    .site-content {
        margin: 0;
        width: 100%;
    }

    .logo-header>img {
        margin: 20px 0;
    }

    .auth-nav>a {
        margin-bottom: 5px;
    }
}