2. in-depth understanding of floating and positioning, and in-depth understanding of floating Positioning

2. in-depth understanding of floating and positioning, and in-depth understanding of floating Positioning
Floating and positioning

1. There are several notes on absolute positioning:

1) absolute positioning is used to offset an "existing" ancestor element "of its" nearest. If no ancestor element has been located, the browser window is used as the benchmark for offset;

2) If the parent element is not positioned, and the sub-mark is set to absolute positioning, but left and top are not set, the sub-element will stay in the original position, but this element is out of the standard stream. This is an excellent way to keep unchanged elements away from the standard stream.