1. :placeholder-shown CSS pseudo-class

    Input elements can sometimes show placeholder text as a hint to the user on what to type in. See, for example, the placeholder attribute in HTML5. The :placeholder-shown pseudo-class matches an input element that is showing such placeholder text.

  2. CSS Scroll Snap

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

  3. Color input type

    Form field allowing the user to select a color.

  4. Date and time input types

    Form field widgets to easily allow users to enter a date, time or both, generally by using a calendar/time input widget. Refers to supporting the following input types: `date`, `time`, `datetime-local`, `month` & `week`.

  5. CSS3 Multiple column layout

    Method of flowing information in multiple columns

  6. types: `<basic-shape>`: `polygon()`

  7. types: `calc()`: gradient color stops support

  8. types: <color>

  9. types: <color>: `color()` (profiled color values)

  10. types: <color>: `color-contrast()`

  11. types: <color>: `color-mix()`

  12. types: <color>: `color()` (profiled color values): relative `color()` syntax

  13. types: <color>: `currentcolor` keyword

  14. types: <color>: `hsl()` (hsl color model)

  15. types: <color>: `hsl()` (hsl color model): alpha parameter

  16. types: <color>: `hsl()` (hsl color model): relative hsl colors

  17. types: <color>: `hsl()` (hsl color model): space-separated parameters

  18. types: <color>: `hwb()` (hwb color model)

  19. types: <color>: `hwb()` (hwb color model): relative hwb colors

  20. types: <color>: `lab()` (lab color model): relative lab colors

  21. types: <color>: `lch()` (lch color model): relative lch colors

  22. types: <color>: `light-dark()`

  23. types: <color>: named colors

  24. types: <color>: named colors: `rebeccapurple`

  25. types: <color>: `oklab()` (oklab color model)

  26. types: <color>: `oklab()` (oklab color model): relative oklab colors

  27. types: <color>: `oklch()` (oklch color model)

  28. types: <color>: `oklch()` (oklch color model): relative oklch colors

  29. types: <color>: `rgb()` (rgb color model)

  30. types: <color>: `rgb()` (rgb color model): alpha parameter

  31. types: <color>: `rgb()` (rgb color model): float values in parameters

  32. types: <color>: rgb hexadecimal notation (`#rrggbb`, `#rgb`, …)

  33. types: <color>: `rgb()` (rgb color model): relative rgb colors

  34. types: <color>: `rgb()` (rgb color model): space-separated rgb() parameters

  35. types: <color>: system colors

  36. types: <color>: system colors: `accentcolor` and `accentcolortext`

  37. types: <color>: system colors: mark, marktext, buttonborder

  38. types: <color>: `transparent` keyword

  39. types: `<image>`: `<gradient>`: `conic-gradient()`: hue interpolation method

  40. types: `<image>`: `<gradient>`: `conic-gradient()`: interpolation color space

  41. types: `<image>`: `<gradient>`: `linear-gradient()`: hue interpolation method

  42. types: `<image>`: `<gradient>`: `radial-gradient()`: hue interpolation method

  43. types: <resolution>

  44. types: <resolution>: `dpcm` unit

  45. types: <resolution>: `dpi` unit

  46. types: <resolution>: `dppx` unit

  47. types: <resolution>: `x` unit

  48. html element: ol: type

  49. javascript built-in: symbol: tostringtag: `tostringtag` available on all dom prototype objects

  50. ecmascript 2019 (es10)