The red div element below would usually be a 3em square. A -o-transform: scale(2.5x); scale is applied to scale the element up two and a half times, or an effective size of 7.5em. As the scale origin is the centre point it scales to overlap this paragraph and partially off the left hand of the page. A blue div has been positioned at the original position to better illustrate how the element has scaled equally from the centre. An opacity has been added so that this text is fully visible. As the transitioned element don't interfere with the flow of the document, z-index can be applied, just as if it had been positioned.