JSFiddle - React, Tailwind, and code Playground

HTML

<div id="outer">
    <div id="flex">
        <label>123</label>
        <input type="text" value="some text" />
    </div>
</div>

CSS

#outer { display: flex; }

#flex {
    display: flex;
    border: 1px solid green;
    outline: 1px solid red;
}

label { flex: 0 0 80px; }