JSFiddle - React, Tailwind, and code Playground
HTML
<span>
<input type="text" />
<input type="button" value="OK" />
</span>CSS
span{display:inline-block; padding:0; margin:0;position:relative}
input[type="text"]{ margin:0;padding:10px;line-height:30px; width:50px}
input[type="button"]{margin:0;padding:8px; height:50px; width:50px}