CSS Little Knowledge points

1,z-index

This property sets the position of an anchored element along the z axis, defined as the axis that extends vertically to the display area. If positive, it is closer to the user and a negative number means farther away from the user.

The Z-index property sets the stacking order of elements. Elements that have a higher stacking order are always in front of elements that are lower in stacking order.

An element can have a negative Z-index property value.

Z-index only works on positioned elements (e.g. position:absolute/relative/fixed)

All major browsers support the Z-index property.

Note: The property value "Inherit" is not supported by any version of Internet Explorer (including IE8).

CSS Little Knowledge points