Browsers such as Chrome and Firefox apply an arbitrary scale to the
current font size if `normal` is used for `line-height`. Firefox uses
1.2 while Chrome uses 1.15. Let's go with the latter for now, it's
relatively easy to change if we ever want to go back on that decision.
This also requires updating the expectations for a lot of layout tests.
The upside of this is that it's a bit easier to compare our layout
results to other browsers', especially Chrome.
This commit introduces proper handling of three intrinsic size keywords
when used for CSS heights:
- min-content
- max-content
- fit-content
This necessitated a few plumbing changes, since we can't resolve these
values without having access to containing block widths.
This fixes some visual glitches on https://www.supabase.com/ as well
as a number of WPT tests. It also improves the appearance of dialogs.
Implements the "top layer" concept from "CSS Positioned Layout Module
Level 4" specification.
- The tree builder is modified to ensure that layout nodes created by
top layer elements are children of the viewport.
- Implements missing steps in `showModal()` to add an element top top
layer.
- Implements missing steps in `close()` to remove an element from top
layer.
Further steps could be:
- Add support for `::backdrop` pseudo-element.
- Implement the "inert" concept from HTML spec to block hit-testing
when element from top layer is displayed.
