.un {
    width: 760px;
    height: 760px;
    margin: 20px;
    border: 20px solid;
    padding: 145px 90px 30px 75px;
    background-color: aquamarine;
}

.deux{ 
    width: 595px;
    height: 570px;
    padding: 120px 95px 30px 95px;
    background-color: magenta;
}

.trois{ 
    width: 400px;
    height: 300px;
    padding: 120px 95px 85px 95px;
    background-color: royalblue;
}

.quatre{
    width: 390px;
    height: 350px;
    background-color: deeppink;
}