Yes, you can replace a video background with a still image for mobile devices on Webflow without causing page load issues by using CSS media queries and background images.
Here's how you can achieve this:
1. First, upload the still image you want to use as the background for mobile devices to your Webflow project and make sure it's optimized for web.
2. Remove the video background element from your Webflow project for mobile devices. You can do this by either hiding the video element or removing it completely.
3. Create a new section or div element where you want to display the still image background for mobile devices. Give this element a class name to target it with CSS.
4. Add a background image style to the element using the class name you just assigned. You can do this by selecting the element, going to the Style panel, and under Background, click on the "+" icon to add the image. Choose the still image you uploaded earlier.
5. Now, you need to set up a CSS media query to apply this background image only on mobile devices. In the Webflow Designer, click on the Settings icon (gear icon) at the top-right corner of the Styles panel, and select "Add custom code". Then, navigate to the "Head" section and paste the following code:
```css
```
Make sure to replace `.your-class-name` with the class name you assigned to the element containing the still image.
6. Finally, you can apply any additional styles or adjustments to the still image element for mobile devices using CSS within the media query. This allows you to fine-tune the display of the background image specifically for mobile devices.
By applying this approach, the video background will be removed on mobile devices, and the still image background will be displayed instead. This will help optimize page load times and improve user experience on mobile devices without causing any issues.