Changing css for existing elements


I would like to change the css for existing elements for example changing the color of the page or set image as background, change color of layout or element in layout like grid.

I know I need to add the style to the elemnt by addStyle or setStyle

What is the process to define new css ? In which file I should put it ?

How can I change the style dynamacily by getinng the style of the element and add new class ?

I am using Vadding 7.



Maybe this page in the Book of Vaadin is what you’re looking for: