Comment 4 for bug 1163906

This is still valid, I have tried numerous combinations such as:

.panel {
    background-image: -gtk-gradient (linear,
                     left top, left bottom,
                     from (alpha (#000, 0.3)),
                     to (alpha (#000, 0.0)));
    font-weight: bold;
}

Nothing works, the panel is always a solid colour. Alpha works (for solid colour) but no gradients.