The following screenshot shows how the complete CSS3 button looks in the same browser:
I think you'll agree—any differences between the image version and the entirely CSS version are trivial. Building visual elements with CSS3 allows our responsive design to be far leaner than if we built it with images. Furthermore, image gradients are well supported in modern mobile browsers, the only trade-off being a lack of gradient support for browsers such as IE 9 and lower versions.
So far, we've looked at a very mundane example of where CSS3 can help in everyday development tasks. However, let's whet our appetite a little and see what real treats CSS3 allows us. Fire up Safari or Chrome and take a look at http://www.panic.com/blog/. Whilst sadly this design isn't responsive, the area of interest for us are the pinned notes at the top. Hover over them and watch as they float out. Nice, eh? In the past this kind of enhancement would have been the domain of resource heavy Flash or JavaScript. Here, it is being achieved entirely through CSS3 transformations. Using CSS3 rather than JavaScript or Flash makes the animation lightweight, maintainable, and therefore perfect for a responsive design. The browsers that support the feature get it, whilst others are none the wiser, merely seeing a static image in its place.
Another great example of CSS3 transformations is http://demo.marcofolio.net/3d_animation_css3/. Again, this isn't a responsive web design, we're just looking at the CSS tricks being employed. Take a look at this in Internet Explorer 9 or Firefox first (as of version 9.0, Firefox still didn't support the necessary CSS3 module). Now, take a look in Safari 5+ or Chrome 16+. The following screenshot doesn't do it much justice so if you're not going to take a look you'll have to take my word for it—it's good:
But great looking effects aren't solely the domain of the Webkit-based Safari and Chrome browsers. The following URL works in Firefox too and is another pure CSS3-based solution:
http://designlovr.com/examples/dynamic_stack_of_index_cards/
Obviously, these effects are not essential for any website. They are a perfect illustration of "progressive enhancement". In browsers that do not support the effects, they merely see the static images. However, users with more modern browsers can enjoy the visual enhancements. Whilst browser support for CSS3 3D Transformations is rather limited, support for CSS3 rules such as text-shadows, gradients, rounded borders, RGBA color, and multiple background images are all widely supported and provide flexible ways of providing solutions to common design problems that have had us all cursing and scratching our heads for years.