header {
    background-color: aqua;
    border: 5px solid red;
}
nav {
    background-color: aqua;
    border: 5px solid red;
}
article {
    background-color: aqua;
    border: 5px solid red;
    width: 300px;
    height: 300px;
    padding: 20px;
    margin: 30px;
    
}
footer {
    background-color: aqua;
    border: 5px solid red;
}
.container {
    background-color: black;
}
.carre {
    width: 200px;
    height: 200px;
    background-color: brown;
 display: flex;
    justify-content: center;
    align-items: center;
}
.trois {
    width: 100px;
    height: 100px;
    background-color: beige;
   
}