1. LCH and Lab color values

    The `lch()` and `lab()` color functions are based on the CIE LAB color space, representing colors in a way that closely matches human perception and provides access to a wider spectrum of colors than offered by the usual RGB color space.

  2. CSS 2.1 selectors

    Basic CSS selectors including: `*` (universal selector), `>` (child selector), `:first-child`, `:link`, `:visited`, `:active`, `:hover`, `:focus`, `:lang()`, `+` (adjacent sibling selector), `[attr]`, `[attr="val"]`, `[attr~="val"]`, `[attr|="bar"]`, `.foo` (class selector), `#foo` (id selector)

  3. dataset & data-* attributes

    Method of applying and accessing custom data to elements.

  4. css at-rule: `@font-face`: src: `format('*-variations')`

  5. css property: --*: `env()`: safe area inset variable `safe-area-inset-bottom`

  6. css property: --*: `env()`: safe area inset variable `safe-area-inset-left`

  7. css property: --*: `env()`: safe area inset variable `safe-area-inset-right`

  8. css property: --*: `env()`: safe area inset variable `safe-area-inset-top`

  9. css property: --*: `env()`: window controls overlay variable `titlebar-area-height`

  10. css property: --*: `env()`: window controls overlay variable `titlebar-area-width`

  11. css property: --*: `env()`: window controls overlay variable `titlebar-area-x`

  12. css property: --*: `env()`: window controls overlay variable `titlebar-area-y`

  13. css property: --*: `var()`

  14. css property: hyphens: hyphenation dictionary for ahmaric (am, am-*)

  15. css property: hyphens: hyphenation dictionary for basque (be, be-*)

  16. css property: hyphens: hyphenation dictionary for catalan (ca, ca-*)

  17. css property: hyphens: hyphenation dictionary for czech (cs, cs-*)

  18. css property: hyphens: hyphenation dictionary for danish (da, da-*)

  19. css property: hyphens: hyphenation dictionary for dutch (nl, nl-*)

  20. css property: hyphens: hyphenation dictionary for finnish (fi, fi-*)

  21. css property: hyphens: hyphenation dictionary for french (fr, fr-*)

  22. css property: hyphens: hyphenation dictionary for hindi (hi, hi-*)

  23. css property: hyphens: hyphenation dictionary for irish (ga, ga-*)

  24. css property: hyphens: hyphenation dictionary for italian (it, it-*)

  25. css property: hyphens: hyphenation dictionary for kannada (kn, kn-*)

  26. css property: hyphens: hyphenation dictionary for latin (la, la-*)

  27. css property: hyphens: hyphenation dictionary for latvian (lv, lv-*)

  28. css property: hyphens: hyphenation dictionary for marathi (mr, mr-*)

  29. css property: hyphens: hyphenation dictionary for oriya (or, or-*)

  30. css property: hyphens: hyphenation dictionary for polish (pl, pl-*)

  31. css property: hyphens: hyphenation dictionary for russian (ru, ru-*)

  32. css property: hyphens: hyphenation dictionary for slovak (sk, sk-*)

  33. css property: hyphens: hyphenation dictionary for spanish (es, es-*)

  34. css property: hyphens: hyphenation dictionary for swedish (sv, sv-*)

  35. css property: hyphens: hyphenation dictionary for tamil (ta, ta-*)

  36. css property: hyphens: hyphenation dictionary for telugu (te, te-*)

  37. css property: hyphens: hyphenation dictionary for turkish (tr, tr-*)

  38. css property: hyphens: hyphenation dictionary for turkmen (tk, tk-*)

  39. css property: hyphens: hyphenation dictionary for welsh (cy, cy-*)

  40. css selector: `:lang()`: matching language codes with wildcards as `:lang(*-latn)`

  41. css selector: universal selector (`*`)

  42. css selector: universal selector (`*`): namespaces (`*|*`)

  43. html attribute: `data-*` attributes

  44. javascript operator: exponentiation (`**`)

  45. javascript operator: exponentiation assignment (`x **= y`)

  46. javascript operator: multiplication (`*`)

  47. javascript operator: multiplication assignment (`x *= y`)

  48. javascript operator: `yield*`

  49. regular_expressions: quantifier: `*`, `+`, `?`, `{n}`, `{n,}`, `{n,m}`

  50. javascript statement: export: `export * as namespace`