JSFiddle - React, Tailwind, and code Playground

HTML

<header class="only-webapp">
</header>

<footer class="only-webapp">
    
</footer>

CSS

@media(max-width: 400px){
    .only-webapp{
        display: none;
    }
}

header, footer{
    height: 50px;
    background-color: #CCC;
    width: 100%;
}
header{
    position: fixed;
    top:0;
}
footer{
    position: fixed;
    bottom: 0;
}