sidenav のコンテンツがコンテナ内にとどまりません。jsfiddle では問題ないように見えますが、私のブラウザでは問題ありません。(Firefox 17.1 Ubuntu Quantal) jsfiddle
<div id="page-wrapper">
<div id="header"></div>
<div id="content-wrapper">
<div id="content">
<h1>Title</h1> 
<p>lipsum...</p>
</div><!-- END content -->
<div id="menu-wrap">
<div id="menu">
<ul>
<li><a href="#">index</a>
<ul>
<li><a href="#">Item one</a></li>
<li><a href="#">Item two</a></li>
<li><a href="#">Item three in the list</a></li>
</ul>
</li>
</ul>
</div><!-- END menu -->
</div><!-- END menu-wrap -->
</div><!-- END content-wrap -->
<div id="footer"></div>
</div><!-- END page-wrapper -->
CSS
h1 {
font-size:34px;
text-align: center;
}
#header {
height: 35px;
width: 100%;
background-color: #336699;
position: fixed;
top: 0px;
z-index: 10;
}
#content-wrapper {
position: absolute;
top: 70px;
bottom: 50px;
left: 0px;
right: 0px;
}
#content {
width: 90%;
float: right;
padding-bottom: 50px;
padding-right: 30px;
line-height: 2em;
}
#menu ul li {
list-style-type: none;
}
#menu ul ul {
display:none;
position: fixed;
}
#menu ul ul a {
}
#menu ul a {
text-decoration: none;
color: black;
}
#menu ul li:hover ul {
display:block;
left: 0;
line-height: 20px;
width: 170px;
height: 400px;
background: #CCC;
border-top-right-radius:1em;
border-bottom-right-radius:1em;
padding-left: 22px;
text-align: left;
line-height: 35px;
padding-top:20px;
font-size: 14px;
}
#menu-wrap {
position:fixed;
top:50px;
width: 52px;
height: 22px;
border-top-right-radius: 6px;
border-bottom-right-radius:6px;
background: rgba(181,181,181,0.5);
text-align: center;
padding-top: 3px;
z-index: 0;
}
#footer {
height: 10px;
width: 100%;
background-color: green;
position: fixed;
bottom: 0px;
}