Hello,

You can create your css file in themes/default/assets/dist/css/ folder and then link it in header file themes/default/views/header.php

Thank you

How can I minify/compile the css like you made?. Also I need to modify the javascript file( print inline style)? how can I modify and minify ?.

Hello,

You can modify the files as you need then run npx gulp libs to compile and minify the code. You will need node 10 or 12 to do so.

If you are not sure, feel free to hire any developer to help you.

Thank you