JSFiddle - React, Tailwind, and code Playground

HTML

<form class="element0">
    <input class="element1" type="text"> <input class="element2" type="button" value="BUTTON">
</form>

CSS

.element0 {
            box-sizing: border-box;
        }

        .element1 {
            width: 400px;
            height: 30px;
            box-sizing: inherit;
            margin-right: 10px;
        }

        .element2 {
            height: 30px;
            box-sizing: inherit;
            padding: 0 10px;
            font-size: 14px;
        }