HTML about the floating thing

Floating
Float:left,right,none,
Note : Floating elements Change the current block-level element to an inline element

Clear floating

Clear:both (clear left and right floating); (clears the floating side);

Overflow:none (clear float); hidden (hidden); scroll (rolling); Auto (Auto (scrolling effect));

Element positioning (position)
Relative: Relative positioning
Absolute: Absolute Positioning
Fixed: Stationary (not recommended, some browsers will be compatible)
Note : The relative and absolute positioning starting points are in the upper-left corner of their parent tag;

1 overlap relationship (z-index)
The default relationship is 0
The value can be any integer
The larger the value, the more forward the position
2 transparency
The smaller the opacity:0~1 value, the more transparent

HTML about the floating thing