I have created this css mod for the back2top. It gives it a modern look with some ability to customize the appearance. I have attached screen shots, and a detailed read me along with the css. I didn't include the entire admin php file. Just the section to change. I didn't remove any existing css. in case someone wanted to use text on the button, but I don't know how the mod will look with text. This gives you a circle button with a hover effect that increases the opacity. Be sure to look at the read me file. I included a lot of detail there. One of the big ones is how to save the "up_arrow.png" to your computer to keep the transparent background. You will need to upload it to the css folder.