1. CSS box-decoration-break

    Controls whether the box's margins, borders, padding, and other decorations wrap the broken edges of the box fragments (when the box is split by a break (page/column/region/line).

  2. CSS3 Box-shadow

    Method of displaying an inner or outer shadow effect to elements

  3. :default CSS pseudo-class

    The `:default` pseudo-class matches checkboxes and radio buttons which are checked by default, `<option>`s with the `selected` attribute, and the default submit button (if any) of a form.

  4. CSS hanging-punctuation

    Allows some punctuation characters from start (or the end) of text elements to be placed "outside" of the box in order to preserve the reading flow.

  5. :indeterminate CSS pseudo-class

    The `:indeterminate` pseudo-class matches indeterminate checkboxes, indeterminate `<progress>` bars, and radio buttons with no checked button in their radio button group.

  6. CSS line-clamp

    CSS property that will contain text to a given amount of lines when used in combination with `display: -webkit-box`. It will end with ellipsis when `text-overflow: ellipsis` is included.

  7. CSS overflow-anchor (Scroll Anchoring)

    Changes in DOM elements above the visible region of a scrolling box can result in the page moving while the user is in the middle of consuming the content. By default, the value of `overflow-anchor` is `auto`, it can mitigate this jarring user experience by keeping track of the position of an anchor node and adjusting the scroll offset accordingly

  8. CSS Reflections

    Method of displaying a reflection of an element

  9. CSS Scroll-behavior

    Method of specifying the scrolling behavior for a scrolling box, when scrolling happens due to navigation or CSSOM scrolling APIs.

  10. CSS text-box-trim & text-box-edge

    Provides the ability to remove the vertical space appearing above and below text glyphs, allowing more precise positioning and alignment. Previously specified as the `leading-trim` & `text-edge` properties.

  11. CSS3 Box-sizing

    Method of specifying whether or not an element's borders and padding should be included in size units

  12. CSS Flexible Box Layout Module

    Method of positioning elements in horizontal or vertical stacks. Support includes all properties prefixed with `flex`, as well as `display: flex`, `display: inline-flex`, `align-content`, `align-items`, `align-self`, `justify-content` and `order`.

  13. Element.getBoundingClientRect()

    Method to get the size and position of an element's bounding box, relative to the viewport.

  14. CSS justify-content: space-evenly

    The "space-evenly" value for the `justify-content` property distributes the space between items evenly. It is similar to space-around but provides equal instead of half-sized space on the edges. Can be used in both CSS flexbox & grid.

  15. CSS3 object-fit/object-position

    Method of specifying how an object (image or video) should fit inside its box. object-fit options include "contain" (fit according to aspect ratio), "fill" (stretches object to fill) and "cover" (overflows box but maintains ratio), where object-position allows the object to be repositioned like background-image does.

  16. css property: -webkit-box-reflect

  17. css property: -webkit-mask-box-image

  18. css property: appearance: `<compat-auto>` (compatibility values `searchfield`, `textarea`, `checkbox`, `radio`, `menulist`, `listbox`, `meter`, `progress-bar`, `button`)

  19. css property: aspect-ratio

  20. css property: background-clip: `content-box`

  21. css property: background-origin: `content-box`

  22. css property: box-align

  23. css property: box-direction

  24. css property: box-flex

  25. css property: box-flex-group

  26. css property: box-lines

  27. css property: box-ordinal-group

  28. css property: box-orient

  29. css property: box-pack

  30. css property: box-shadow: `inset`

  31. css property: box-shadow: multiple shadows

  32. css property: box-shadow: spread radius

  33. css property: box-sizing: `padding-box`

  34. css property: clip-path: `fill-box` and `stroke-box`

  35. css property: mask-origin: `fill-box`

  36. css property: mask-origin: `stroke-box`

  37. css property: mask-origin: `view-box`

  38. css property: object-view-box

  39. css property: offset-path: `<coord-box>`

  40. css property: transform-box

  41. css selector: `:indeterminate`: applies to `<input type="checkbox">` elements