body {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    background-color: #e0e0e0;
    transition: background-color 0.3s;
}

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

#theme-toggle {
    position: absolute;
    top: 1rem;
    right: 1rem;
    padding: 0.5rem 1rem;
    font-size: 1rem;
    color: #fff;
    background-color: #007bff;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}

#theme-toggle:hover {
    background-color: #0056b3;
}

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

body.dark-mode #theme-toggle:hover {
    background-color: #eee;
}