body {
    margin: 0;
    border: 0;
    padding: 0;
}

.content {
    max-width: 1000px;
    margin: auto;
}

.header {
    position: absolute;
    top: 0px;
    height: 5em;
    width: 100%;
    line-height: 5em;
    background-color: lightseagreen;
    text-align: center;
}
.header .content {
    font-size: 2em;
}

.pages {
    position: absolute;
    top: 5em;
    bottom: 2em;
    width: 100%;
    overflow: hidden;
    overflow-y: visible;
    background-color: white;
}
.pages .page {
    opacity: 0.25;
    aheight: 10em;
    margin: 2em;
    border: 0;
    padding: 2em;
    background-color: lightgoldenrodyellow;
}
.pages .page.visible {
    opacity: 1;
    transition: opacity 2s;
}

.footer {
    position: absolute;
    height: 2em;
    width: 100%;
    line-height: 2em;
    bottom: 0px;
    background-color: lightseagreen;
    text-align: center;
}

.footer .content {
}