How can I set a video background in Webflow that fills the screen vertically for all devices (desktop, tablet, mobile)?

To set a video background in Webflow that fills the screen vertically for all devices, you can follow these steps:

1. Prepare your video: First, make sure you have a video file in a suitable format (such as .mp4 or .webm) that you want to use as your background. Ensure that the video is optimized for web and appropriately compressed to minimize file size without compromising quality.

2. Add a new section: In Webflow's Designer, go to the desired page and add a new section by clicking on the "+" button or using the keyboard shortcut "S".

3. Set section styles: With the new section selected, go to the Styles panel. Set the section's dimensions to 100vh for height (which ensures it fills the entire viewport vertically) and 100% for width (to fill the viewport horizontally).

4. Add a video element: Inside the section, add a video element by selecting the "Video" option from the add element menu or dragging the video element from the Elements panel.

5. Link your video: With the video element selected, go to the Settings panel. Choose the video source by clicking on "Upload" or "Link" and selecting your video file. You can either upload the video directly to Webflow or use an externally hosted video.

6. Set video styles: Back in the Styles panel, set the video element's position to "absolute" and adjust the z-index as needed. This allows the video to be positioned in the background of the section.

7. Adjust positioning and sizing: Still in the Styles panel, set the video element's left and right positioning to "0" and the top and bottom positioning to "0" as well. This ensures that the video fills the entire section. You may need to adjust these values if you have other elements overlapping with the video.

8. Enable object-fit property: To make the video fill the container while maintaining its aspect ratio, add a custom code to the head of your page. In the head section of the page settings, click on "Custom code" and add the following CSS:

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9. Test and adjust: Preview your site and verify that the video background fills the screen vertically on various devices. If adjustments are needed, go back to the Designer and modify the section or video element styles as required.

Keep in mind that video backgrounds can impact page load times, so make sure to optimize your video file and consider its impact on performance. Additionally, it's recommended to include a fallback image for devices that don't support video backgrounds or have slow internet connections.

By following these steps, you should be able to set up a video background in Webflow that fills the screen vertically across all devices.