No that's the output not the input that's creating the design. The main aspect of CSS is coding, therefore you're a coder not a designer first. If you created something in Photoshop then you're "designing" however if you create something using CSS then you're coding. Yes there is an aspect of design in it as the output is what you're making, however you won't find CSS under design on tutorial sites or w3.org as it's coding.