JSFiddle - React, Tailwind, and code Playground

HTML

<form>
 
    <div><input type="search" /></div> <div><input type="submit"></div>
</form>

CSS

form {display: table; table-layout: fixed; width: 100%; background: hotpink;}
form div {
  position: relative;
display: table-cell;
    width: 80%
}
form div + div {
    width: 20%;
}
form div [type="search"], [type="submit"] {
width: 100%;
  -webkit-box-sizing: border-box; /* Safari/Chrome, other WebKit */
    -moz-box-sizing: border-box;    /* Firefox, other Gecko */
    box-sizing: border-box;         /* Opera/IE 8+ */
}