Style won't work --- 404 status in console to retrieve files

Hi. I have been trying to customize ERPNext and made few changes in the CSS file.
But now I am facing an issue related to the styling, the server returns 404 on styling files and the front-end is a mess.
I am attaching the screenshot for the issue. I will thankful if I can get any help from the forum.

This type of error is normally a permissions problem. Check that you have the same permissions and ownership on your custom files as you have on the installation files

Thanks for the response, I will check the permissions, but I have added only one custom file and haven’t touched others, but the server response is 404 for those files too (not custom – orignal files).

The “cause” of the error shows as script - maybe your customisations have blocked or changed a core file. You could try a

bench update --reset

to restore the default files, and then try your customisations