CSS Quick Reference
Three: Gradients

Between 2008 and 2012 gradients finally appeared in web browsers although as of 2012 they still all required a browser prefix. By 2013 it works unrpefixed on all desktop and smartphone browsers. Not the WebKit and Mozilla directions are expressed in the reverse of the official standard and the Opera prefixed ones. If you ever see all four with the same callouts for direction, you know that isn't going to work without trying it, it's internally inconsistent.

Fig 1.0 Altering the direction of the gradient; the first (optional) word is direction

linear-gradient(to left, #000000, #ffffff);
linear-gradient(to right, #000000, #ffffff);
linear-gradient(to bottom, #000000, #ffffff);
linear-gradient(to top, #000000, #ffffff);