1. CSS Counter Styles

    The @counter-style CSS at-rule allows custom counter styles to be defined. A @counter-style rule defines how to convert a counter value into a string representation.

  2. CSS font-palette

    The font-palette CSS property allows selecting a palette from a color font. In combination with the `@font-palette-values` at-rule, custom palettes can be defined.

  3. CSS ::marker pseudo-element

    The `::marker` pseudo-element allows list item markers to be styled or have their content value customized.

  4. CSS Scroll Snap

    CSS technique that allows customizable scrolling experiences like pagination of carousels by setting defined snap positions.

  5. CSS Variables (Custom Properties)

    Permits the declaration and usage of cascading variables in stylesheets.

  6. CSS3 tab-size

    Method of customizing the width of the tab character. Only effective using 'white-space: pre', 'white-space: pre-wrap', and 'white-space: break-spaces'.

  7. css at-rule: `@container`: style queries for custom properties

  8. css at-rule: `@custom-media`

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

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

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

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

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

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

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

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

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

  18. css selector: custom state pseudo-class selector (`:state()`)