body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
}
.login-container {
    width: 300px;
    margin: 100px auto;
    padding: 20px;
    background: #fff;
    border-radius: 5px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}
.error {
    color: red;
    margin-bottom: 15px;
}
.header {
    background: #333;
    color: white;
    padding: 15px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.menu ul {
    list-style: none;
    padding: 0;
    margin: 20px;
}
.menu li {
    background: white;
    margin-bottom: 5px;
    border-radius: 5px;
}
.menu a {
    display: block;
    padding: 10px;
    text-decoration: none;
    color: #333;
}
/* Additional styling for other pages would go here */