@charset "utf-8";
/* CSS Document */
body{
    margin: 0;
    padding: 0;
}
section{
    width: 600px;
    height: 800px;
    background-color: yellow;
    border: 2px dashed black;
    margin: auto;
    position: relative;
}
#box1{
    background-color: orange;
    width: 200px;
    height: 200px;
    border: 2px solid black;
    position: absolute;
    left: 50px;
    top: 50px;
}
#box2{
    background-color: orange;
    width: 200px;
    height: 200px;
    border: 2px solid black;
    position: absolute;
    right: 50px;
    top: 50px
}
#box3{
    background-color: orange;
    width: 200px;
    height: 200px;
    border: 2px solid black;
    position: absolute;
    right: -50px;
    bottom: -50px;
}
#box4{
    background-color: orange;
    width: 200px;
    height: 200px;
    border: 2px solid black;
    position: relative;
    left: 50%;
    top: 50%;
    transform: translate(-50%,-50%);
    /*Ces 3 propriétés permettent de centrer*/
}