nav:not(.mm-menu) {
    display: none;
}

.header,
.content {
    text-align: center;
}

.header {
    background: #777;
    font-size: 16px;
    font-weight: bold;
    color: #fff;
    line-height: 40px;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
    /* width: 100%; */
    height: 40px;
    padding: 0 26px;
    float: left;
    position: absolute;
    margin-left: 15px;
    top: 28px;
}

    .header.fixed {
        position: fixed;
        top: 0;
        left: 0;
    }

.footer.fixed {
    position: fixed;
    bottom: 0;
    left: 0;
}

.header a {
    display: block;
    width: 52px;
    height: 18px;
    padding: 11px;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 999999;
}

    .header a:before,
    .header a:after {
        content: '';
        display: block;
        background: #fff;
        height: 2px;
    }

    .header a span {
        background: #fff;
        display: block;
        height: 2px;
        margin: 6px 0;
    }

.content {
    padding: 150px 50px 50px 50px;
}