"As you might know, HTML5 introduced many exciting features for Web developers. One of the features is the ability to specify gradients using pure CSS3..." Er,

"As you might know, HTML5 introduced many exciting features for Web developers. One of the features is the ability to specify gradients using pure CSS3..." Er, no. HTML5 did not introduce the gradient feature. CSS3 introduced the feature (inspired by an implementation in WebKit). This has nothing to do with HTML5, though people these days seem to like using that as a buzzword for "modern web standards."