I want to learn custom theme design for OpenWrt

I have used Argon theme, Material Theme and able to modify thes as per need. But all of them are just css based graphical changes.

Main structure is remain same. But I want to design my own custom theme.

By this time I realised the mai body of the UI is generated by some js and lua file but I am unable to understand them.

Can somebody please help me out....

There is no themeing facilities for ui generated content like forms or widgets. You can only influence header and footer markup and CSS styles.