body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}

header {
    background-color: #333;
}

header nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
}

header nav ul li {
    margin: 0;
}

header nav ul li a {
    display: block;
    padding: 14px 20px;
    color: #fff;
    text-decoration: none;
}

header nav ul li a:hover {
    background-color: #575757;
}

.container {
    padding: 20px;
}

.error {
    color: red;
}

.success {
    color: green;
}

footer {
    background-color: #f1f1f1;
    text-align: center;
    padding: 10px;
    position: fixed;
    width: 100%;
    bottom: 0;
}