“If designers think that using HTML5 and CSS3 makes them a better
designer just because they use them, then they’re sorely misguided.”Include an element only if it accomplishes some usability-related purpose.
If the design is not made more usable by a particular technique (whether
via CSS3, JavaScript or something else), then the designer should
reconsider whether the extra code is worth the effort. Decoration only goes
so far and often has an effect opposite to the one intended, so consider
yours carefully before including it in your design.
Another example of an animation that enhances usability is found on Soh
Ta n a k a ’s n e w w e b s i t e. Look at the screenshot below from this post on his
blog: