html
{height: 100%;}

body
{background-color: #ffec9e;
 margin: 0;
 height: 100%;}

.flexbox
{display: flex;
 height: 100%;
 overflow: hidden;}

.side
{background-color: #fcc800;
 text-align: center;
 padding: 30px 30px;
 flex: 0 0 180px;
 overflow: scroll;}

.top
{}

label 
{display: inline-block;
 font-weight: bold; 
 padding: 3px 6px;
 margin: 2px;
 border: solid 1.5px #000000;
 cursor: pointer;
 position: relative;
 top: 20px;
 width: 100px;}

input 
{display: none;}

.title
{height: 0;
 padding: 0;
 overflow: hidden;
 opacity: 0;
 position: relative;
 top: 20px;}

.check:checked + .title
{height: auto;
 margin: 10px;
 opacity: 1;}

.link
{text-decoration: none;
 color: #000000;
 display: block;}

.hidden
{position: relative;
 top: 40px;}

.main
{flex: 1 1 auto;
 padding: 100px 100px 0px;
 overflow: scroll;
 background-color: #ffec9e;}

.footer 
{text-align: center;
 position: relative;
 top: 200px;
 padding: 50px;}