body {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100vh;
    background-color: #6FB776;
}

header {
    width: 100%;
    background-color: #15771F;
    color: #fff;
    padding: 10px 0;
    position: fixed;
    top: 0;
    left: 0;
    z-index: 1000; 
}

header nav a {
    margin-left: 10px;
}

main {
    width: 80%; 
    height: 80%;
    margin-top: 100px; 
    margin-bottom: 100px;;
    padding: 20px;
}

footer {
    width: 100%;
    color: #fff;
    padding: 10px 0;
    position: fixed; 
    bottom: 0;
    left: 0;
    text-align: center;
}


div {
    border: 1px solid black;
    margin: 10px;
    background-color: #15771F;
}

a{
    color: azure;
}

p {
    margin: 10px;
}

h1 {
    margin: 10px;
    margin-left: 80px;
}

h2 {
    margin: 10px;
}

h3 {
    margin: 10px;
}

.col{
    display: flex;
    margin: 20px;
    padding: 20px;
}

.colonne1{
    flex: 1;
    flex-basis: 50%; /* 1/3 */
    background-color: #ebeadf;
    border: 1px solid black;
    margin: 10px;
    padding: 10px;
}

.colonne2{
    flex: 2;
    flex-basis: 50%; /* 2/3 */
    background-color: #ebeadf;
    border: 1px solid black;
    margin: 10px;
    padding: 10px;
}