JSFiddle - React, Tailwind, and code Playground

HTML

<div>
Something
</div>
<button id="b1">
Button to hide
</button>
<div>
Something
</div>
<button id="b2">
Button to toggle hiding
</button>

CSS

#b1 {
  display: inline-block;
  height: 63px;
  transition: height 250ms ease-in-out;
  overflow: hidden;
}

#b1.hidden {
  height: 0px;
}

JavaScript

const buttonToHide = document.getElementById("b1");
document.getElementById("b2").addEventListener('click', () => {
  if (buttonToHide.classList.contains("hidden")) {
    buttonToHide.classList.remove("hidden");
  } else {
    buttonToHide.classList.add("hidden");
  }
})