body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
    transition: background-color 0.3s, color 0.3s;
}

.dark-mode {
    background-color: #121212;
    color: #ffffff;
}

header {
    background: #35424a;
    color: #ffffff;
    padding: 10px 0;
    text-align: center;
}

.dark-mode header {
    background: #1f1f1f;
}

main {
    padding: 20px;
}

h1, h2 {
    color: #333;
}

.dark-mode h1, .dark-mode h2 {
    color: #ffffff;
}

footer {
    text-align: center;
    padding: 10px 0;
    background: #35424a;
    color: #ffffff;
}

.dark-mode footer {
    background: #1f1f1f;
}