PostCSS Cascade Layers lets you use
following the Cascade Layers Specification.
For more information on layers,
checkout A Complete Guide to CSS Cascade Layers
by Miriam Suzanne.
The CSS anchor positioning specification defines anchor positioning, “where a positioned element can size and position itself relative to one or more ‘anchor elements’ elsewhere on the page.” This CSS Anchor Positioning Polyfill supports and is based on this specification.
add flexibility to how absolutely positioned elements
can be placed within a layout.
Instead of being sized and positioned
based solely on the position of their containing block,
the proposed new functions allow absolutely positioned elements
to be placed relative to one or more
author-defined anchor elements.
OddBird’s Popover Attribute Polyfill – built in collaboration with Keith Cirkel and used in production by GitHub – lets developers preview the upcoming mechanism for displaying popover content on top of other page content, drawing the user’s attention to specific important information or actions that need to be taken.
This polyfills the HTML
HTMLElement, as well as the
popovertargetaction attributes on