JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">
    <form>
        <input type="search">
        <span class="submit"></span>
    </form>
</div>

CSS

#container {
    width: 300px;
    border: 1px solid black;
    height:30px;
}

input[type="search"] {
    width: calc(100% - 40px);
    margin:0;
    padding:0;
    height:30px;
    float:left;
}
.submit {
   float:left;
    width: 40px;
    height: 30px;
    background-color: red;
}