.un {
    width: 760px;
    height: 760px;
    margin: 20px;
    border: 20px solid;
    padding: 120px 90px 50px 75px;
    background-color: aquamarine;
}

.deux{ 
    width: 50;
    height: 600px;
    padding: 120px 120px 0px 95px;
    background-color: black;
}

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

.quatre{
    width: 300px;
    height: 300px;
    background-color: azure;
}