JSFiddle - React, Tailwind, and code Playground

HTML

<div class="main">
    <div class="content">content content content content content content content content content content content content content content content content content content content content content content content content content content content content content content content content content content content content content content content content</div>
    <div class="sidebar">sidebar sidebar sidebar sidebar sidebar sidebar sidebar sidebar sidebar sidebar sidebar sidebar sidebar sidebar sidebar sidebar sidebar sidebar sidebar sidebar sidebar</div>
</div>

CSS

.main{
    white-space:nowrap;
}
.content{
    display:inline-block;
    white-space:normal;
    vertical-align:top;
    float:right;
    margin-left:100px;
}
.sidebar{
    display:inline-block;
    width:100px;
    vertical-align:top;
    white-space: normal;
}

@media screen and (max-width:400px){
    .content{
        float:none;
        margin-left:0px;
    }
    .sidebar{
        display:block;
        width:auto;
}