I understand that most background gradients are implemented by creating an image one-pixel wide and (say) 1000 pixels tall, and repeating the image along the x-axis.
What happens in that case if the page is more than 1000 pixels tall? Is there to make a background gradient that can cope with a page of any length?
Common practice is to declare the background color of your page to be the color of the bottom most pixel of your gradient image. So when the gradient is over, at least there is no hard cut.