The close button styling for e.g. nautilus tabs are currently broken. We get no special style on either :hover or :active.

The current CSS for this is:

/* close button styling */
.notebook tab .button,
.notebook tab .button:active,
.notebook tab .button:hover {
    border-image: none;
    border-style: none;
    background-image: none;
    background-color: transparent;
}

.notebook tab .button GtkImage {
    border-radius: 3px;
    color: mix(@theme_fg_color, @theme_base_color, 0.6);
    border-style: solid;
    border-color: transparent;
    border-width: 1px;
    padding: 1px;

    icon-shadow: 0 1px @button_text_shadow;
}

.notebook tab .button GtkImage:hover {
    color: @theme_fg_color;
    border-color: alpha(black, 0.1);
}

.notebook tab .button GtkImage:active,
.notebook tab .button GtkImage:active:hover {
    background-color: alpha(black, 0.08);
    box-shadow: inset 0 1px alpha(black, 0.05);
    color:  @button_active_text;
    icon-shadow: 0 1px @button_active_text_shadow;

    border-color: alpha(black, 0.27) 
                  alpha(black, 0.13) 
                  alpha(black, 0.13) 
                  alpha(black, 0.13);
}

.notebook tab .button GtkImage:backdrop {
    color: mix(@theme_unfocused_fg_color, @theme_unfocused_base_color, 0.7);
    icon-shadow: none;
}

.notebook tab .button GtkImage:backdrop:hover {
    color: @theme_unfocused_fg_color;
}


Where things like ".notebook tab .button GtkImage:hover" are not right
in the new world where :hover doesn't propagate  from the button to the
child image. However, if i change this to 

.notebook tab .button:hover GtkImage {

It doesn't seem to get applied. Isn't this right?