Hello @ashu
Greetings of the day..!!
Please let us know more clearly in which section you want to apply CSS or JS below are the core files in which CSS and JS are used and Blades files are present for specific sections where these classes are used.
Core CSS file path
Webkul >> Shop >> src >> Resources >> assets >> CSS >> app.css
css.png
Core JS file path
Webkul >> Shop >> src >> Resources >> assets >> js >> app.js
js.png
Thanks & Regards..!!