The problem is CSS styles are not applying throgh user control. but it works normal Pages
It looks like the URL for the stylesheet file is not referenced properly. During normal page, the reference path given finds the file and applies the css but through User-control, the path is not correctly formed and hence the file is not found at the given location not letting any CSS to apply.
Make sure that the CSS file path is correctly formed or apply the css in-file itself.
Have a look at this tip, it might help:
Resolving Paths in a Multi-Folder WebSite[
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