W3 Container Class
Having documented a lot of design techniques I realise that I have not done so for the w3-container class.
I use the w3-container class extensively on this website. The class provides a 16px padding to any HTML element.
Upate - December 2024 - for some reason I see a visit to this page after 3 years!
The HEADING and PARAGRAPH elements provide their own (additional) padding.