Inline Shopify Forms (Prestige theme) render too narrow, especially on mobile; users want wider/max-width forms.
Attempts shared:
Add CSS to theme.liquid or theme.css targeting app classes (e.g., ._inline_whyqz_45 ._formContainer_whyqz_30 { max-width: 65–96% !important; }, or ._noImage_whyqz_158 { width: 75%; max-width: 900px; }).
General tip to increase the percentage for wider forms.
Roadblocks:
Changes didn’t take effect for some; one user highlighted the form’s width is controlled by a :host rule with a mobile breakpoint at max-width: 490px, likely within the app’s encapsulated styles (not easily overridden via theme CSS). Screenshots in the thread show the :host rule and narrow mobile rendering.
Workarounds and updates:
Styling the parent container (.shopify-app-block) with padding/border/background can improve appearance while awaiting fixes.
One participant reports the issue seemed to be resolved internally by Shopify over time; after that, theme-level tweaks were easier to adjust.
Status:
No confirmed community code fix for overriding the app’s :host breakpoint. Partially resolved for some (possible Shopify-side fix); others still affected and using parent-container styling as a workaround. The thread remains open without a definitive solution.
Summarized with AI on December 19.
AI used: gpt-5.
Hi all, adding to the question to find a solution.
The main change I want to make is to get the form width to be max width on mobile. (I can get by with the lack of other css changes to shopify forms app, as they sometimes work in google inspector but don’t translate when I add it to shopify base css file, or within the theme css section.)
So basically I want to change the breakpoint px size, which is currently at max-width: 490px for mobile. This is being controlled by the :host css (see screenshot). Does anyone know where the css for this :host exists within shopify for me to change it?
See screenshots: this is too narrow for some mobile
Hi there,
Did you find a solution?
I have the same problem. The form from the Forms App is way too smal compared to the rest of the page.
I tried adding the code to the end but nothing helped.
Support chat told me to post it here.
Looking at the application form of the original post makes me think its still unsolved.
Please help !
I think the problem was fixed internally by shopify because after I added some styling to the form as a compromise, I realized that the problem was fixed soon after. If it isn’t fixed after awhile for you, try adding css/styling to the parent container that the form lives in… so for example this the code I used: