body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    transition: background-color 0.3s, color 0.3s;
}

body.light-mode {
    background-color: #f0f0f0;
    color: #000;
}

body.dark-mode {
    background-color: #333;
    color: #fff;
}

.container {
    text-align: center;
}

input, button {
    margin: 10px;
    padding: 10px;
}

#countdown {
    font-size: 2em;
    margin-top: 20px;
}

#logoutButton {
    display: none;
}