Pseudo class selector is added to the keyword selection unit for selecting a particular state element specifies. Start a single colon: to. Dynamic pseudo-classes are divided into selectors, selectors pseudo-class configuration, the negative pseudo class selector.
Dynamic pseudo class selector:
: State element [not] access link {}
: Visited {} {installed state after the element has already been visited]
: Focus {} {occur when selected track mode]
: Hover {} {hover state occurs when the element of]
: Active {} [state] mouse click occurs element
Note: this order can not be changed, link and visited pseudo static class selector, regardless of the order may be
Structure pseudo class selector: an element selected for
1、
: First-child select the first element
: The last element last-child
: Nth-child (n) select the first n elements
Example: section> p: nth-child (3) represented by: in the third element section, p is selected if
2. Select the first of several elements with the same tag name of the element
:nth-of-type(n)
Example: section> p: nth-of-type (3) represented by: p is selected in the third section
3, select the penultimate n elements
：nth-last-child(n)
Negative pseudo class selector
Format:: not () in addition to an element, other add style
Example: section> p: not (: nth-child (3)) except for the first three others to style p
Format: In addition to several elements, add other styles
：not( )：not（）