I took the standard Tgc theme and doubled the size of everything, then cleaned up the diagonal lines and shadows. I changed the shade icon to match modern Xfce but other than that everything looks identical to Tgc, just twice as big. I used a text editor for everything so the theme will change colors properly based on the current appearance theme.

This will look absolutely ridiculous on a standard-resolution screen. It's intended for only very high-DPI screens, such as a Retina Macbook Pro, a PC laptop with a full 1080p 14" screen, or a tablet designed for a high-DPI OS like Android. I recommend using it with a font DPI of 144, as shown in the screenshot. Download it at:

http://frammish.org/Tgc-huge.tgz