Wt

Currently, depending on the layout direction of the app, Wt will go through logic to set the properties of offsets on the left and right correctly.
Meaning a call like cpp setOffset(5, Wt::Side::Right) will result in a css margin-right: 5px in a LTR localization, and a css margin-left: 5px in a RTL environment.
While this works, this relies on the developer to always keep this in mind, and allows for easily being overlooked.

Now enter {margin/padding}-inline (border may also be considered).
For example see margin-inline-start.

This offers an easy way to set the margin, and make it depend on the layout direction. This will avoid having to manually switch the values in logic, and delegate that to the browser.