图片发自简书App
1～26:
plate
bento
#fancy
plate apple
#fancy pickle
.small
bento .small,plate .small
bento orange
bento,plate
*
plate *
plate+apple
bento~pickle
plate>apple
orange:first–child
apple:only–child,pickle:only–child
.small:last–child,pickle
plate:nth–child(3)
bento:nth–last–child(4)
apple:first–of–type
plate:nth–of–type(even)
plate:nth–of–type(2n+3)
apple:only–of–type
.small:last–of–type
bento:empty
apple:not(. small)
