HTML code on the page displays in mobile only

Topic summary

A Shopify store owner is experiencing a display issue where a page with embedded HTML integration code only renders in desktop view at exactly 150% Chrome zoom—otherwise defaulting to mobile formatting.

Initial Diagnosis:
A PageFly support representative identified that the page width was restricted to 726px in the base.css file.

Proposed Solution:
Add CSS code to set .page-width { max-width: 100% !important; } either in base.css or within the theme.liquid file’s <head> section.

Current Status:
The fix initially appeared successful, but created new problems—contact forms on the homepage and support page now stretch excessively wide to the page edges. A revised CSS solution targeting a specific template ID (.section-main__padding-template--15574529730306) was suggested, but the issue remains unresolved.

Technical Context:
The page uses Mariana integrations via HTML div and JavaScript embedded in theme.liquid.

Summarized with AI on November 10. AI used: claude-sonnet-4-5-20250929.

Actually, that seems to have made my contact-us forms go a little haywire and they now stretch as WIDE as the page. There’s one at the bottom of my home page and one on this page: https://barrecode.co/pages/support