Test CSS: layer position classes

.pos-fixed-left-top

.pos-fixed-center-top

.pos-fixed-right-top

.pos-fixed-left-center

.pos-fixed-center

.pos-fixed-right-center

.pos-fixed-left-bottom

.pos-fixed-center-bottom

.pos-fixed-right-bottom

.pos-abs-center

.pos-abs-center-x

.pos-abs-center-y

.pos-rel-center

.pos-abs-left-top

.pos-abs-center-top

.pos-abs-right-top

.pos-abs-left-center

.pos-abs-center

.pos-abs-right-center

.pos-abs-left-bottom

.pos-abs-center-bottom

.pos-abs-right-bottom