JSFiddle - React, Tailwind, and code Playground

by Snj

HTML

<div class="container">
  <div class="imgbox">
    <div class="box">
      <a href="https://unsplash.it/50/50/?random" target="_blank">
          <img class="img_div show_image" src="https://unsplash.it/120/120/?random">
        </a>
    </div>
    <div class="box">
      <a href="https://unsplash.it/50/50/?random" target="_blank">
        <img class="img_div show_image asdasd" src="https://unsplash.it/120/120/?random">
      </a>
    </div>
    <div class="box">
      <a href="https://unsplash.it/50/50/?random" target="_blank">
        <img class="img_div show_image" src="https://unsplash.it/120/120/?random">
      </a>
    </div>
    <div class="box">
      <a href="https://unsplash.it/323/641/?random" target="_blank">
        <img class="img_div show_image" src="https://unsplash.it/120/120/?random">
      </a>
    </div>
  </div>
</div>

CSS

body { background-color: grey; }
img { display: block; }
div {
  display: inline-block;
  margin: 1rem;
}
:root { --mozopt: 1.0; }

.container {
  display: inline-block;
  margin: 1rem;
  margin-top: 1rem;
  width: 54rem;
  height: 22rem;
  margin-top: 3rem;
}
.imgbox {
  display: inline-flex;
  justify-content: center;
  width: 100%;
}

.box > a > img {
  transition: opacity, transform, 0.3s ease-in-out;
}
.box > a > img:not(:hover) {
  opacity: var(--mozopt);
}

.box > a > img:hover {
    z-index: 15;
    opacity: 1.0;
    transform: translateX(25%) translateY(25%) scale(1.5);
    /* transform-origin: 50% 50%; */
    transform-origin: center;
}

JavaScript

.target//let elementsArray = document.querySelectorAll(".show_image");
const add_mozopt = _ => document.body.style.setProperty("--mozopt", 0.3);
const remove_mozopt = _ => document.body.style.setProperty("--mozopt", 1.0);

document.querySelectorAll(".show_image").forEach(elem => {
    elem.addEventListener("mouseover", add_mozopt);
    elem.addEventListener("mouseout", remove_mozopt);
}, false);



//good way:
if(typeof neverDeclared == "undefined") //no errors
// But the best looking way is to check via :
if(typeof neverDeclared === typeof undefined) 



/*
setTimeout(function() {
  elem.removeEventListener('mouseover', add_mozopt);
  elem.removeEventListener('mouseout', add_mozopt);
}, 5000);

document.addEventListener('mouseover', function(e){
  if (e.target.tagName=="IMG"){
   	document.body.style.setProperty("--aop", 0.3);
  }
})
document.addEventListener('mouseover', function(e){
	if (e.target.tagName=="IMG"){
		document.body.style.setProperty("--aop", 1.0);
  }
})
*/