JSFiddle - React, Tailwind, and code Playground

HTML

<div class="searchbox">
    <input class="inputb" type="text" />
</div>

CSS

.searchbox {
    width: 96%;
    height: 40px; 
    background-color:#0099FF;
    padding: 0 2%;
}
.inputb {
    width: 100%;
    margin:0;
    padding:0;
 }
@media (max-width: 490px) {
    .searchbox {
        padding-left: 3%;
        padding-right:3%;
    }
}