JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrapper">
    <input type="text">
    <button> <span>Auswählen</span>

    </button>
</div>

CSS

.wrapper {
    width:100% display: table;
}
input {
    display: table-cell;
    width: 100% float: left;
}
button {
    display: table-cell;
    width: auto;
}