$("#addBodyContent").on("click", function() {
$("<p>Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Vestibulum tortor quam, feugiat vitae, ultricies eget, tempor sit amet, ante. Donec eu libero sit amet quam egestas semper. Aenean ultricies mi vitae est. Mauris placerat eleifend leo.</p>").appendTo(".page-wrap .content");
});
$("#addFooterContent").on("click", function() {
$("<p>Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Vestibulum tortor quam, feugiat vitae, ultricies eget, tempor sit amet, ante. Donec eu libero sit amet quam egestas semper. Aenean ultricies mi vitae est. Mauris placerat eleifend leo.</p>").appendTo(".site-footer .content");
});
* {
margin: 0;
}
html,
body {
height: 92%;
font-family: "Helvetica", "Arial", "FreeSans", "Verdana", "Tahoma", "Lucida Sans", "Lucida Sans Unicode", "Luxi Sans", sans-serif;
}
.page-wrap {
min-height: 100%;
box-sizing: border-box;
padding: 10px;
}
.page-wrap:after {
content: "";
display: block;
}
.site-footer {
background: black;
position: relative;
left: 0;
right: 0;
bottom: 0;
min-height: 100px;
text-align: center;
padding: 10px;
color: white;
box-sizing: border-box;
}
button.dark:hover {
background-color: rgba(0, 0, 0, 0.7);
}
button.dark {
background-color: black;
border: 3px solid black;
padding: 10px 30px;
color: white;
cursor: pointer;
transition: .7s;
}
button.light:hover {
background-color: #CCCCCC;
}
button.light {
background-color: white;
border: 3px solid white;
padding: 10px 30px;
color: black;
cursor: pointer;
transition: .7s;
}
.content p {
margin-bottom: 10px;
}
.content {
border-top: 1px solid black;
padding-top: 10px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="page-wrap">
<h1>Header</h1>
<br>
<button id="addBodyContent" class="dark">Add Content</button>
<br>
<br>
<div class="content"></div>
</div>
<footer class="site-footer">
<h2>Footer</h2>
<br>
<button id="addFooterContent" class="light">Add Content</button>
<br>
<br>
<div class="content"></div>
</footer>