Half of the mobile page is blank, how should it be fixed to full screen

Topic summary

A Shopify store owner reports that half of their mobile page (bmcarcover.com) displays as blank space, as shown in an attached screenshot.

Proposed Solutions:

  • CSS overflow fix: Add overflow-x: hidden and max-width: 100% rules to the CSS file to prevent horizontal overflow issues

  • Implementation guidance: Insert CSS code in the theme.liquid file before the </head> tag, with a before/after screenshot demonstrating the fix

  • Root cause identification: The issue may stem from specific code in theme.liquid or footer.liquid files (referenced in an attached screenshot)

The original poster indicated difficulty locating where to add the CSS code. Multiple community members provided step-by-step instructions for accessing the theme code editor and implementing the fix.

Summarized with AI on October 27. AI used: claude-sonnet-4-5-20250929.

Like this. my web:www.bmcarcover.com

Hi,

Hope this will work

  • Open Your Theme Code and Check for “overflow” or “width” Problems in CSS

add this safe fix at the bottom of your CSS file (if you are not sure about the problem)

CSS example

body {
  overflow-x: hidden !important;
}

html, body {
  max-width: 100% !important;
}

I didn’t find where to add this css

Hi @Jim_65 ,

  1. Go to Online Store → Theme → Edit code.
  2. Open your theme.liquid file
  3. In theme.liquid, paste the below code before

Result:

If my reply is helpful, kindly click like and mark it as an accepted solution.
Thanks!
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This is mainly caused by this code. You should find it in theme.liquid or footer.liquid