Position

Options:

1. static (default)
2. relative
3. absolute
4. fixed
5. sticky (CSS3) The element is positioned according to the normal flow of the document, and then offset relative to its nearest scrolling ancestor and containing block (nearest block-level ancestor), including table-related elements, based on the values of top, right, bottom, and left. The offset does not affect the position of any other elements. This value always creates a new stacking context. Note that a sticky element “sticks” to its nearest ancestor that has a “scrolling mechanism” (created when overflow is hidden, scroll, auto, or overlay), even if that ancestor isn’t the nearest actually scrolling ancestor. This effectively inhibits any “sticky” behavior (see the GitHub issue on W3C CSSWG).

Demo for sticky: https://mdn.mozillademos.org/zh-CN/docs/Web/CSS/position$samples/Sticky_positioning?revision=1631402

Some attribute related to position

1. top, right, bottom, left Only working when position set relative, absolute, sticky or fixed
2. z-index

Samples:

1. Match Parent(Spinner、Model’s background)
2. Why position: fixed isn’t working in sometimes?
3. Why z-index isn’t working in sometimes?

Overflow

Options:

1. auto
2. scroll
3. hidden
4. visible (default)
5. overlay

Relative attribute

1. overflow-x
2. overflow-y

Question:

1. What if it set overflow-x: hidden and overflow-y: visible?
2. Can we use it to highlight columns when hover cells in a table?
3. Didn’t overflow: hidden working?
4. Can we use it to scroll in the table except the header?

Transition

Grammar transition: property duration timing-function delay;

Samples:

1. Expand / collapse elements with transition.
2. Transition when elements enter / leave.

CSS Methods

var( <custom-property-name> , <declaration-value>? )

• <custom-property-name>
• <declaration-value>

calc( <calc-sum> | <calc-product> | <calc-value> )

Some Other New Features

Color Value Support

• rgb(0 0 0) (CSS4)
• rgba(0 0 0 / 50%) (CSS4)
• hsl(0deg 0% 0%) (CSS4)
• hsla(0deg 0% 0% / 50%) (CSS4)