Add this to gtk-widget.css in MediterraneanNightTheme for gnome 3.10.

gistfile1.txt

/***************
 * Header bars *
 ***************/
.header-bar {
    border-width: 0 0 1px;
    border-style: solid;
    border-color: shade(@borders, 0.90);
    border-radius: 15px 15px 0px 0px;
    box-shadow: inset 0 -1px shade(@borders, 1.30);
    background-color: @theme_bg_dark_color;

    padding: 6px 6px 5px 6px;
}

.header-bar:backdrop {
    border-image: linear-gradient(to top,
                                  @unfocused_borders,
                                  @unfocused_borders 1px,
                                  @theme_unfocused_bg_color 1px) 0 0 2;
    box-shadow: none;
    background-color: @theme_bg_dark_color;
}

.header-bar .button.text-button {
    padding: 2px 16px;
}

.header-bar .button.image-button {
    padding: 5px 4px 5px 5px;
}

.header-bar .title {
    font: Bold 11;
    color: @theme_text_dark_color;

}

.header-bar .subtitle {
    font: 9;
    color: @theme_text_dark_color;

}
.header-bar GtkSeparatorToolItem,
.header-bar .separator,
.header-bar .separator:insensitive,
.header-bar .pane-separator
 {
    border-color: 		 alpha (#000, 0.24);
    border-bottom-color: alpha (#000, 0.08);
    border-right-color:  alpha (#000, 0.08); 
}
/*******
 * CSD *
 *******/
.titlebar {
    text-shadow: 0 1px @wm_title_shadow;


    border-radius: 7px 7px 0px 0px;
}

/* this is the default titlebar that is added by GTK
 * when client-side decorations are in use and the application
 * did not set a custom titlebar.
 */
.titlebar.default-decoration {
    border: none;
    box-shadow: none;
}

.titlebar .title {
    font: Bold 11;
}

.titlebar:backdrop {
    text-shadow: none;
    background-image: none;
    background-color: @theme_bg_dark_color;
}

.titlebar .titlebutton {
    icon-shadow: 0px 1px @theme_shadow_dark_color;
    color: @wm_title;
    background: none;
    padding: 5px 5px 6px 5px;

    border-radius: 3px;
    border-width: 1px 1px 2px 1px;
    border-color: transparent;
    border-style: solid;
    border-image: none;
}

.titlebar .titlebutton:hover {
    background-image: linear-gradient(to bottom,
                                      @button_hover_gradient_color_a,
                                      @button_hover_gradient_color_b);
}

.titlebar .titlebutton:active {
    background-image: linear-gradient(to bottom,
                                      @borders,
                                      shade(@theme_bg_dark_color, 0.95)
                                      );
    color: @theme_selected_fg_color;
    icon-shadow: none;
}

.titlebar .right .titlebutton:first-child {
    border-left: 1px solid @menu_separator; 
}

.titlebar .right .titlebutton:last-child {

}

.titlebar .left .titlebutton:last-child {
    border-right: 1px solid @menu_separator; 
}

.titlebar .left .titlebutton:first-child {

}

.titlebar .titlebutton:backdrop {
    background-image: none;
    color: @wm_unfocused_dark_title;
    border-image: none;
    icon-shadow: none;
}

.window-frame {
    border-color: darker(@theme_bg_dark_color);
    border-radius: 7px 7px 0 0;
    border-width: 1px;
    border-style: solid;

    box-shadow: 0 2px 8px 3px @theme_shadow_dark_color;

    /* this is used for the resize cursor area */
    margin: 10px;
}

.window-frame:backdrop {
    box-shadow: 0 2px 5px 1px @theme_shadow_dark_color;
}

@Dvad, would you like helping a little bit keeping this theme at least moderately working? I would love to get it (or something close to it) usable with newer gtk3 versions.

In particular, I am trying to keep the skeleton of a Debian package at:

https://github.com/rbrito/pkg-mediterranean-gtk-themes

Since you seem to know more about theming than I do (I know next to nothing, but I am willing to learn and I have some experience with "vanilla" CSS), I would love to learn from you.

Hi, @rbrito,

Sadly, I am really not an expert in gtk theming. All I've done is to copy-paste from Adwaita theme some chunk of CSS.
Problem is, it is hard to find good documentation on gtk3 theming. But there are workarounds: GTKParasite helped me a lot.

This said, I am OK to collaborate a little, because I love this theme. Could you show me the current state of the theme in your repo on header-bar? Just a screenshot. I think I've made some minor changes I did not published, but I don't really remember.

Cheers,