SO Simple HTML5 page layout

HTML

<script src="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.1.0/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.1.0/css/bootstrap.min.css">
<div class="container">
    <div class="row-fluid" align="center">
    	<div class="jumbotron span12">
            <h1>Header</h1>
        </div><!-- close jumbotron -->
</div> <!-- close row -->
    <div class="row">
        
            
          
<div class="span3" id="side-nav" data-spy="affix" data-offset-top="200">
    <!-- data-offset-top is the distance you need to scroll before the affix behaviour kicks in -->
    <h5>Option 1</h5>
    <h5>Option 2</h5>
    <h5>Option 3</h5>
    <h5>Option 4</h5>

   
        </div> <!-- end span3 -->
    
    <div class="span9 main-content">
        <h2>Content Here</h2>
       Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.
       Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus...

CSS

.jumbotron{
    height:200px;
    background-color:olive;
}

#side-nav{
    background-color:teal;
}

/* define where you want the side nav after it's affixed */
#side-nav.affix{
    left:100px;
}


.span9.main-content{
    background-color:grey;
    float:right;
}

@media (min-width: 768px) and (max-width: 979px) {
#side-nav.affix{ width:166px; 
}
}
@media (max-width: 767px) {
    #side-nav.affix{
    width:100% !important;
}

#side-nav.affix{
    position:static;
    top:auto;
    height:300px;
}
}