Make my Website More mobile Friendly

The project is my portfolio website and the source code is well written and the only task is to make it more friendly and responsive so that it looks while any user on mobile tablets or any other device and responsive as well . There won’t be any change in the desktop version and want to add animations and illustration in background instead of simple blue color . I will provide you the source code and all the data necessary the only work needs to be done is to make it responsive and mobile friendly
you can take the help of brittanychiang.com and similar i want to make it looks like while viewing in mobile