body {
    font-family: Arial;
    background: #f4f4f4;
    margin: 0;
    padding: 0;
}

.login-container {
    width: 300px;
    margin: 100px auto;
    padding: 30px;
    background: white;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
    text-align: center;
}

input, button {
    width: 90%;
    padding: 10px;
    margin: 10px 0;
}

nav {
    background: #333;
    padding: 10px;
    text-align: center;
}

nav a {
    color: white;
    margin: 0 15px;
    text-decoration: none;
}

main {
    padding: 20px;
    max-width: 800px;
    margin: auto;
    background: white;
    margin-top: 20px;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
}

th, td {
    border: 1px solid #ddd;
    padding: 8px;
}