/virtualboxes/syprunner/files/Zukitre/gtk-3.0/gtk-fallback.css

 1.menu {
 2	border-image: linear-gradient(to top,
 3		alpha(@borders, 0.80),
 4		alpha(@borders, 0.60) 33%,
 5		alpha(@borders, 0.50) 66%,
 6		alpha(@borders, 0.15)) 1 1 1 1/ 1px 1px 1px 1px;
 7}
 8
 9.menubar .menu {
10	border-image: linear-gradient(to top,
11		alpha(@borders, 0.80),
12		alpha(@borders, 0.60) 33%,
13		alpha(@borders, 0.50) 66%,
14		transparent 99%) 1 1 1 1/ 1px 1px 1px 1px;
15}