JSFiddle - React, Tailwind, and code Playground

HTML

<div id="header">

</div>

<div id="left_side">    
</div>

<div id="content">
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</div>

CSS

body {   
    width: 100%;
    height: auto;
    padding: 0;
    margin: 0px auto;
    font-family: Calibri, Georgia, Ubuntu-C;  
    font-size: 16px;
    margin-bottom: 20PX
}

#header{
    width: 100%;
    height: 139px;
    background: RED;   
}


#left_side{
    width: 210px;
    height: 300px;
    background:#000000;
    background-repeat:repeat-y;
    overflow:hidden; 
    position:absolute;
    font-size: 16px;
}

#content{
     height: 250px;
    overflow:auto;
     padding: 20px;
     margin-left: 230px;
     margin-right: 20px;
    padding-bottom: 30px;
    background:ORANGE;
 }