<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>Transformacion escala</title>
    <style>
        body {
            display: flex;
            align-items: center;
            justify-content: center;
            height: 100vh;
            color: white;
            font-family: Arial;
        }
        
        .container {
            border: 1px solid red;
        }
        /*.cuadrado:hover {*/
        
        .container:hover .cuadrado {
            /*transform: scale(x, y);*/
            /*transform: scale(0 = 0% del tamaño - 1 = 100% del tamaño);*/
            /*transform: scale(2)*/
            /*transform: scale(.5);*/
            transform: scale(2, .5);
        }
        
        .cuadrado {
            width: 200px;
            height: 200px;
            background: #7dc900;
            margin: 20px;
            transition: .3s;
        }
    </style>
</head>

<body>
    <div class="container">
        <div class="cuadrado">
            Hola mundo!
        </div>
    </div>
</body>

</html>