Another progress bar approach is to nest two DIVs, and then calculate the inner DIV's % width using CSS calc();
This demo is creating progress bars using DIVs and CSS, from a collection. In the collection are both a progress amount, and a max amount, from which the progress bar is created.
The styling of the progress bar is done in the designer, and you can see this e.g. in the Style Guide at the bottom of this page.
In your Style Guide page, you can define the styling of your progress bar classes easily. Here's an example of that approach;
Click the View in Webflow's Designer button at the top of this page, to explore the page design.