Jack also comes with the Jack Hover stack. Jack Hover allows you to modify the style of Jack on hover. You can modify a single style attribute or combine multiple for interesting effects. While you can definitely radically change Jack on hover, I recommend that you exercise some restraint and keep things simple.
Jack has 8 border styles that you can choose from. Below are a sample of what is possible when you customize the border styles. You can really get some interesting effects when you combine multiple Jacks stacks together. That is where the fun begins.