body {
display: flex;
justify-content: space-around;
align-items: center;
height: 100vh;
margin: 0;
background-color: #f0f0f0;
}
.cuadrado {
width: 150px;
height: 150px;
border: 2px solid #333;
}
.rojo {
background-color: red;
}
.verde {
background-color: green;
}
.azul {
background-color: blue;
}