Support CSS logical properties (for margins, borders and padding)
Since GTK 4 properly handles :first-child and :last-child on every widget, we now encounter the CSS specificity issues in theme more often than in GTK 3.
To help those issues, it would be great if GTK could support CSS logical properties (and the value logical, hopefully) for margins/borders/padding. Not only it would make avoiding specificity issues much easier, but also it would make the CSS styling much simpler.
Here is the CSS documentation (Editor's Draft): https://drafts.csswg.org/css-logical/
Here is a list of the logical properties for margins, borders and padding: https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Logical_Properties#Properties_for_margins_borders_and_padding