JSFiddle - React, Tailwind, and code Playground

HTML

<div class="first-div">
</div>
<div class="second-div">
    <div class="inner-div">Test</div>
</div>
<button onclick="toggle()">Toggle Border</button>

CSS

*
{
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}
.first-div
{
    background-color: red;
    min-height: 50px;
}
.second-div
{
    background-color: blue;
    min-height: 50px;
    overflow: auto;
}
.inner-div
{
    margin: 10px;
    text-align: center;
}

JavaScript

toggle = function() {
    if (document.getElementsByClassName('second-div')[0].style.border) {
        document.getElementsByClassName('second-div')[0].style.border = "";
    }
    else {
        document.getElementsByClassName('second-div')[0].style.border = "1px solid";
    }
};