[gnome-builder] gui: add border at bottom of frame header

[Christian Hergert <chergert src gnome org>]

commit f0c9c0d4a6bbcebe487f28a9bb098dc05d31307a
Author: Christian Hergert <chergert redhat com>
Date:   Wed Jun 19 13:17:25 2019 -0700

    gui: add border at bottom of frame header
    
    Fixes #944

 src/libide/gui/ide-frame-header.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/src/libide/gui/ide-frame-header.c b/src/libide/gui/ide-frame-header.c
index 99a67ea87..94a0084b7 100644
--- a/src/libide/gui/ide-frame-header.c
+++ b/src/libide/gui/ide-frame-header.c
@@ -363,7 +363,9 @@ ide_frame_header_update_css (IdeFrameHeader *self)
       g_string_append        (str, "  background: none;\n");
       g_string_append_printf (str, "  background-color: %s;\n", bgstr);
       g_string_append        (str, "  transition: background-color 400ms;\n");
-      g_string_append        (str, "  transition-timing-function: ease; }\n");
+      g_string_append        (str, "  transition-timing-function: ease;\n");
+      g_string_append_printf (str, "  border-bottom: 1px solid shade(%s,0.9);\n", bgstr);
+      g_string_append        (str, "  }\n");
       g_string_append        (str, "button { background: transparent; }\n");
       g_string_append        (str, "button:hover, button:checked {\n");
       g_string_append_printf (str, "  background: none; background-color: shade(%s,.85); }\n", bgstr);