body {
    font-family: Arial, sans-serif;
    background: #f4f4f4;
    color: #222;
    margin: 0;
    padding: 2rem;
}

body.dark-mode {
    background: #222;
    color: #e4e4e4;
}

main {
    max-width: 700px;
    margin: 0 auto;
    background: white;
    padding: 2rem;
    border-radius: 8px;
}

body.dark-mode main {
    background: #333;
    color: #e4e4e4;
}

a {
    color: #0066cc;
    text-decoration: none;
}

h3 {
    font-weight: normal;
    font-size: 150%;
}

h3 span {
    font-size: 67%;
}

button#theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.5rem;
    float: right;
    padding: 0;
}

button#theme-toggle:hover {
    color: #f4f4f4;
}

button#theme-toggle:focus {
    outline: none;
}

button#theme-toggle:active {
    transform: scale(0.9);
}

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

@media screen and (max-width: 768px) {
    body {
        padding: 10px;
        font-size: 16px;
    }

    main {
        max-width: 100%;
        padding: 15px;
    }

    h1 {
        font-size: 1.5em;
        word-wrap: break-word;
    }

    a {
        display: inline-block;
        padding: 10px;
        margin: 10px 0;
    }
}