1. Go to Design and click "Template Designer"
2. Click "Advanced" and then scroll to the bottom in the next column (where you see things like "Text Color" and "Link Color") until you see "Add CSS". Click "Add CSS".
3. In the box, type this:
This will only work if you click "Instead of Title and Description" when you upload your header.
If you choose "Behind Title and Description", it will not work. Instead, you need to add a different code. Follow the same instructions as above, but insert the following code instead: