Things like strokes, drop shadow, positioning (not usually a good thing,) color, gradient, font family, and the list goes on and on. Properties which the CSS will copy out all depend on how designed and stylized your element is in Photoshop.
This will copy the CSS that it takes to style an HTML element. You can right-click on any layer at any time and choose “Copy CSS”. I set the color of the text to white and then dragged it to the middle of the button shape. Grab the Text tool (T) and add a small bit of text to the front of our button. I’m going to create a new Rounded Rectangle and set the fill to a green color and I’m going to give it a drop shadow and set the color of the drop shadow to a very dark green, set the opacity of the drop shadow to 100%, set the size of the drop shadow to 0, and set the angle of the drop shadow to 90 degrees. You will see some of the pros and the cons of using this method for creating web design elements or entire web pages. We’ll take code for text and a button that we’ve created and move it over into Dreamweaver and adjust and tweak the CSS code until it creates a graphic similar to what we had in Photoshop. In this tutorial, we’ll talk about the somewhat ill-advised “Copy CSS” feature of Photoshop and how it works.