JSFiddle - React, Tailwind, and code Playground

HTML

<div>
   <input type=text class="topInput">
   <input type=text class="bottomInput">
</div>

CSS

input{
    display:block;
    margin:0px;
    padding:0px;
    line-height:0px;
    border:1px solid gray;
}

input.topInput{
    border-radius:4px 4px 0px 0px;
    border-bottom:none;
}

input.bottomInput{
    border-radius:0px 0px 4px 4px;
}