Are there any workarounds or tips to create long modal windows in Webflow that can be scrolled and have a fixed background with a semitransparent overlay?

You can absolutely create scrollable long modal windows in Webflow with a fixed background and semitransparent overlay using some key layout settings and interaction structure.

1. Create the Modal Structure

• Create a div block for the modal wrapper and position it as fixed, full screen (top: 0, bottom: 0, left: 0, right: 0).
• Set its z-index high (e.g., 9999) and background color to rgba(0, 0, 0, 0.5) for transparency.
• Inside this wrapper, create another div block for the modal content. This will hold the scrollable content.

2. Enable Scroll for Modal Content

• Set the modal content div to have:
• Fixed width or max-width pattern (e.g., 600px or 80vw)
• Max height (e.g., 80vh) and overflow: auto
• This ensures the modal content scrolls internally while retaining a fixed overlay behind.

3. Center the Modal Content

• Use Flexbox on the modal wrapper (display: flex; justify: center; align: center) to center the modal even when viewport size changes.
• Scroll behavior will stay inside the modal content div if properly limited with height and overflow settings.

4. Lock Background Scroll

• To prevent scrolling of the underlying page when the modal is open:
• Create an interaction on the modal trigger that:
  • Uses the “Page > When Modal Opens” set to overflow: hidden on the body
• On modal close:
  • Set overflow: auto (or visible) back to the body

5. Add Close Functionality

• Add a close button inside the modal.
• Use Webflow Interactions to hide or scale down the modal wrapper on click.
• Optionally, add a click interaction on the background wrapper (outside modal content) to also trigger the close.

6. Optional Enhancements

• To ensure mobile-friendliness, always test your vh height limits since mobile browsers may ignore or miscalculate vh units due to address bar sizes.
• Consider using calc(100vh - some value) or dynamic sizing with min-height for better responsiveness.

Summary

To create a long, scrollable modal window with a fixed semitransparent overlay, use a full-screen fixed modal wrapper with centered modal content set to a limited height and overflow: auto. Lock background scroll using overflow: hidden on the body, and use interactions for opening and closing the modal.