JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    
    <div class='container'>
        <div class='row' id='header'>
            Something
        </div>
        <div class='row' id='content'>
            Something
        </div>
    </div>
</body>

CSS

body
{
    padding:0px;
    margin:0px;    
}
#header
{        
    height: 25vh;
    width:100%;
    background-color:green;    
}

#content
{    
    height:75vh;
    width:100%;
    background-color:blue;        
}