JSFiddle - React, Tailwind, and code Playground

HTML

<div class="fix-wrapper">
    <div class="one">ONE<br>ONE<br>ONE</div>
    <div class="two">TWO</div>
</div>

CSS

.one{
    background: #cccccc;
}
.two{
    background: #000000;
    color: #ffffff;
}

.fix-wrapper {
    width: 100%;
    position: fixed;
    top: 0;
}