body {background-color: #f0ffff; margin-left: 70px; margin-bottom: 200px}
a:link {color: #0000dd; text-decoration: none}     
a:visited {color: #0000dd; text-decoration: none; font-weight: lighter}  
a:hover {color: #0000dd; text-decoration: underline} 
a:active {color: #0000ee}

html, body {margin:0; padding:0;}

#page-background {
    position:fixed;
    top:0;
    left:0;
    width:100%;
    height:100%;
    z-index:-1;
    }

#page-overlay {
    position:fixed;
    top:50%;
    left:50%;
    width:50px;
    height:auto;
    z-index:0;
    }

#content {
    position:relative;
    top:0;
    z-index:1;
    margin-left:70px;
    margin-bottom:200px;
    }
    
    
#c1 {
background-color: #f0f0f0;}    
#c2 {
background-color: #f0f0ff}    
#c3 {
background-color: #fff0ff;}    
#c4 {
background-color: #fff0f0;}
#c5 {
background-color: #fffff0;}
#c6 {
background-color: #f0fff0;}
#c7 {
background-color: #f0ffff;}
    
    
ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
  overflow: hidden;
  background-color: #f0ffff;
  position: -webkit-sticky; /* Safari */
  position: sticky;
  top: 0;
}

li {
  float: left;
  padding-right: 10px;
  padding-bottom: 3px;
}