JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
    <div class="element">
        <div>col 1</div>
        <div>col 2</div>
    </div>
</div>

<div class="container">
    <div class="element">
        <div>col 1</div>
        <div><input type="text" /></div>
    </div>
</div>

CSS

.container { width: 400px; padding: 10px; }
.element { margin-bottom:15px; height: 40px; }
.element div { vertical-align: top; height: 40px; }
.element div:first-child { float: left;width: 100px; background-color: red;}
.element div:last-child { margin-left: 100px; background-color: green; }

.element INPUT {width: 100%; }