JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="//netdna.bootstrapcdn.com/bootstrap/3.0.0/css/bootstrap.min.css">
<script src="//netdna.bootstrapcdn.com/bootstrap/3.0.0/js/bootstrap.min.js"></script>
<div class="row ml-3">
    <div class="col-sm-4 sidebar-outer">
        <div class="sidebar">fixed sidebar
        <h1>dewa</h1></div>
    </div>
    <div class="col-sm-8">
        <div class="content">fluid content
             <h1>Content</h1>
            <h1>Content</h1>
            <h1>Content</h1>
            <h1>Content</h1>
            <h1>Content</h1>
            <h1>Content</h1>
            <h1>Content</h1>
             <h1>Content</h1>
             <h1>Content</h1>
             <h1>Content</h1>
             <h1>Content</h1>
             <h1>Content</h1>
             <h1>Content</h1>
        </div>
    </div>
</div>

CSS

.row {
    margin-top:10px;
    margin-left : 50px
}

.sidebar-outer {
    position: relative;
}
.sidebar {
    background-color: red;
}
.content {
    background-color: lightblue;
}

@media (min-width: 768px) {
    .sidebar {
        position: fixed;
    }
}