Linear Gradients With Progressbars

There are two aspects of the jQuery UI progressbar widget we can style. First, there's the container. This is essentially the progressbar border. While you can style the background of the container, it's best to just leave it alone. The second aspect is the value div. This goes inside the container and increases or decreases in width as the value of the progressbar changes. This is the part the user is interested in, and we can apply interesting styles to it, such as a linear gradient.