Trying to style AfterSell App

Shopify Apps

Topic summary

A developer is attempting to customize the styling of the AfterSell app within a local development environment for a client’s Shopify store.

Attempted solutions that failed:

  • Adding CSS to the app’s Custom CSS field in the editor
  • Adding CSS directly to theme code files
  • Using !important declarations
  • Verifying CSS selectors are correct

Current issue:
The custom styles are not applying at all—they don’t even appear in browser developer tools, suggesting they may not be loading.

Status: The developer is seeking guidance on whether the AfterSell app can be styled at all, and what troubleshooting steps to take next. They note being new to Shopify development. No responses or solutions have been provided yet.

Summarized with AI on November 2. AI used: claude-sonnet-4-5-20250929.
1

Hi!

I’m trying to style the AfterSell app in my local Dev env that I have set up for an existing client site.

I have tried adding CSS into the Custom CSS field in the editor itself and into the CSS files in the code I’ve triple checked the selectors are correct and even used !important. Neither of these approaches work, the styles don’t even seem to appear in my browsers dev tools.

Any idea if I can even style this App? I am very new to Shopify so I have no idea what else to check

Thanks!
Jamie