Pen Settings



CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URLs added here will be added as <link>s in order, and before the CSS in the editor. You can use the CSS from another Pen by using its URL and the proper URL extension.

+ add another resource


Babel includes JSX processing.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

+ add another resource


Add Packages

Search for and use JavaScript packages from npm here. By selecting a package, an import statement will be added to the top of the JavaScript editor for this package.


Auto Save

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

Format on Save

If enabled, your code will be formatted when you actively save your Pen. Note: your code becomes un-folded during formatting.

Editor Settings

Code Indentation

Want to change your Syntax Highlighting theme, Fonts and more?

Visit your global Editor Settings.


                progress.c-progress.js-progress(value="0" max="1")

    h1 Mobile-friendly reading progress with minimal JS
    each section in [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 ]
        p Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin porta risus urna, non molestie risus dignissim ut. Maecenas varius leo quis lectus rhoncus mollis. Donec condimentum, ipsum ac consectetur rhoncus, tellus dolor volutpat libero, vitae volutpat mi eros a metus. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin at dolor non enim pretium tempor id gravida dui. Pellentesque porta metus in felis molestie gravida. Sed in diam mi. Suspendisse vel odio dapibus, aliquam nisi ut, condimentum ante.

        p In tincidunt dui ac ante efficitur posuere. Integer diam nisl, scelerisque sit amet est non, venenatis suscipit tortor. Integer ultricies bibendum ante et tempus. Donec nibh sem, tempor ac consequat at, rhoncus at elit. Fusce aliquam tempus ex, vitae venenatis ipsum mattis aliquet. Aliquam convallis lacinia lectus, sit amet consectetur augue aliquam eu. Morbi enim mi, scelerisque non viverra in, mattis vitae ligula. Donec nulla lacus, interdum ac tortor vitae, consectetur sodales lorem. Morbi iaculis ante sit amet lacus maximus, non elementum libero scelerisque. Vivamus id magna convallis, ullamcorper nisl eu, efficitur ipsum. Praesent eros ante, maximus et quam vitae, laoreet blandit neque.


                $progress-color: lighten(#1e1935, 20)

    position: fixed
    top: 0
    left: 0
    width: 100%
    height: 5px
    appearance: none
    background: transparent
    border: none
    color: $progress-color
    z-index: 5

        background: transparent

        background: $progress-color

        background: $progress-color

    margin: 0 auto
    width: 65%
    max-width: 700px
    font: 16px/#{1.5} "Poppins", Arial, sans-serif
    margin-bottom: 2em

    font: bold 46px/#{1.25} "Poppins", Arial, sans-serif
    margin: 1.5em 0

    -webkit-font-smoothing: antialisased
    box-sizing: border-box


                //- Reading Progress Indicator

    const progress = document.querySelector('.js-progress');
    const body = document.body;
    const html = document.documentElement;

    const updateSizes = () => ({
        height: Math.max(body.scrollHeight, body.offsetHeight, html.clientHeight, html.scrollHeight, html.offsetHeight),
        vh: Math.max(html.clientHeight, window.innerHeight || 0)

    let scrollY = 0;
    let sizes = updateSizes();

    const update = () => progress.setAttribute('value', 100 - (sizes.height - scrollY - sizes.vh) / sizes.height * 100);

    const onScroll = () => {
        scrollY = (window.pageYOffset || document.scrollTop) - (document.clientTop || 0);

    const onResize = () => {
        sizes = updateSizes();

    if(progress) {
        progress.setAttribute('max', 100);
        window.addEventListener('scroll', onScroll, false);
        window.addEventListener('resize', onResize, false);