5.0.0 – ESM support, CSS Selectors Level 4

• Added support for CSS Selectors Level 4 and legacy pseudos in specificity calculation, i.e. :has(), :not(<selector-list>), :is(), :matches(), :-moz-any(), :-webkit-any(), :where(), :nth-child(... of <selector-list>) and :nth-last-child(... of <selector-list>)
• Package
  • Changed supported versions of Node.js to ^12.20.0, ^14.13.0 and >=15.0.0
  • Converted to ES modules. However, CommonJS is supported as well (dual module)
  • Changed bundle set to provide dist/csso.js (an IIFE version with csso as a global name) and dist/csso.esm.js (as ES module). Both are minified
  • Bumped css-tree to 2.0