Style the palettes

[manuq]

Palettes need to be styled for the GTK+3 shell port.

• correct alignments and sizes respecting the sugar cell size
• separator below the header is not visible
• separators should be grey and get the whole palette width

Also for the icon in the palette see #3836.

Attaching gif animations for reference.

[manuq]

Reference animation.

[manuq]

Reference animation.

[manuq]

This makes the activity separator the correct color and almost get all the width:

--- a/gtk3/theme/gtk-widgets.css.em
+++ b/gtk3/theme/gtk-widgets.css.em
@@ -445,14 +445,15 @@ SugarPaletteWindow SugarGroupBox *:insensitive {
     padding: 0px $(subcell_size)px;
 }
 
-.menu * {
-    color: @white;
-}
-
 .menuitem {
     padding: $(subcell_size)px $((subcell_size * 3 - font_height) / 2)px;
 }
 
+.menuitem.separator {
+    padding: $(subcell_size)px 0;
+    color: @button_grey;
+}
+
 .menuitem:prelight {
     background-color: @button_grey;
 }

[manuq]

Toolkit part of the fix.

[manuq]

Artwork part of the fix.