body {
    background-color: #f4f4f4;
    color: #333;
}

.main-header {
    background-image: url("../images/montagne.jpg");
    background-color: #999;
    background-repeat: no-repeat;
    background-size: cover;
    background-position: center;
    color: white;
    height: 300px;
}

.promo-box {
    background-color: rgba(52, 152, 219, 0.3);
    border: 1px solid rgb(52, 152, 219);
}

footer {
    background-color: #2c3e50;
    color: #ecf0f1;
}