footer {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    background-color: #007BFF;
    color: #fff;
    text-align: center;
    padding: 20px 0;
}

.btn-back {
    background-color: #333;
    color: #fff;
    border: none;
    padding: 10px 20px;
    border-radius: 10px;
    cursor: pointer;
}

.btn-back:hover {
    background-color: #555;
}