CodePen Embed - YzQgGpy

<head>
  <link href='https://fonts.googleapis.com/css?family=Montserrat' rel='stylesheet'>
</head> 
<div class="flex_random">
        <div class="random">Lorem ipsum dolor sit amet consectetur adipisicing elit. Rerum laboriosam id nesciunt aliquam sunt unde incidunt voluptates. Perspiciatis quam ratione id obcaecati? Necessitatibus ullam ratione earum voluptatibus, natus officiis voluptas?
        </div>
        <div class="random">Lorem ipsum dolor sit amet consectetur adipisicing elit. Numquam nemo aspernatur praesentium quos officiis pariatur harum non atque aperiam! Cum quasi accusantium facere aperiam iusto dicta quia nobis et error.
        </div>
        <div class="random">Lorem ipsum dolor sit amet consectetur adipisicing elit. Ex fugiat eius cumque atque alias facere, doloribus veritatis modi. Vitae nam quia error iusto soluta eos totam porro tenetur repellendus iste.
        </div>
    </div>

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Montserrat';
    background-color: white;
    text-align: center;
}

.random.over{
    background-color: #4C35E0;
    opacity: 0.8;
    color: white;
}

.flex_random {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-evenly;
}

.random {
    width: 30%;
    margin: 10px;
    border-style: solid;
    border-width:1px ;
    border-color: #4C35E0;
    border-radius: 10px;
    padding: 15px;
    transition: ease-in-out 0.4s;
}

let box = document.querySelectorAll('.random');


box.forEach(function(item){
    item.addEventListener("mouseenter", function(){
        item.classList.add("over");
        item.addEventListener("mouseout", function(){
            item.classList.remove('over')
        })
    })
})

This Pen is owned by Romain Malaterre on CodePen.

See more by @romain-malaterre on CodePen

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