initial theme stylesheets support

data/media/adwaita_style.css

@@ -0,0 +1,4 @@
+@define-color dark_bg #353535;
+@define-color light_bg #F6F5F4;
+
+@import url("style.css");

data/media/arc_style.css

@@ -0,0 +1,4 @@
+@define-color dark_bg #31373D;
+@define-color light_bg #EDEDED;
+
+@import url("style.css");

data/media/style.css

@@ -4,9 +4,6 @@
   inclusion in templates
 */
 
-@define-color dark_bg #31373D;
-@define-color light_bg #EDEDED;
-
 @binding-set window-bindings {
   bind "<ctl>w" { "close-window" () };
   bind "<ctl><shift>b" { "toggle-bibtex" () };

uberwriter/UberwriterWindow.py

@@ -177,13 +177,13 @@ class UberwriterWindow(Gtk.ApplicationWindow):
         # Init file name with None
         self.set_filename()
 
-        self.style_provider = Gtk.CssProvider()
-        self.style_provider.load_from_path(helpers.get_media_path('style.css'))
+        # self.style_provider = Gtk.CssProvider()
+        # self.style_provider.load_from_path(helpers.get_media_path('arc_style.css'))
 
-        Gtk.StyleContext.add_provider_for_screen(
-            Gdk.Screen.get_default(), self.style_provider,
-            Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION
-        )
+        # Gtk.StyleContext.add_provider_for_screen(
+        #     Gdk.Screen.get_default(), self.style_provider,
+        #     Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION
+        # )
 
         # Markup and Shortcuts for the TextBuffer
         self.markup_buffer = MarkupBuffer(

uberwriter_lib/AppWindow.py

@@ -16,11 +16,12 @@ from gettext import gettext as _
 
 import gi
 gi.require_version('Gtk', '3.0') # pylint: disable=wrong-import-position
-from gi.repository import GLib, Gio, Gtk, GdkPixbuf
+from gi.repository import GLib, Gio, Gtk, Gdk, GdkPixbuf
 
 from uberwriter import UberwriterWindow
 from uberwriter.Settings import Settings
 from uberwriter_lib import set_up_logging
+from uberwriter_lib import helpers
 from uberwriter_lib.PreferencesDialog import PreferencesDialog
 from . helpers import get_builder, get_media_path
 
@@ -36,9 +37,27 @@ class Application(Gtk.Application):
     def init(self):
         """Init main application"""
 
+        # set theme variant (dark/light) 
         dark = self.settings.get_value("dark-mode")
         Gtk.Settings.get_default().set_property("gtk-application-prefer-dark-theme", dark)
 
+        # set css for current theme
+        self.style_provider = Gtk.CssProvider()
+
+        themes = {
+            "Arc": "arc_style.css",
+            "Arc-Dark": "arc_style.css",
+            "Arc-Darker": "arc_style.css",
+        }
+
+        theme = Gtk.Settings.get_default().get_property("gtk-theme-name")
+        self.style_provider.load_from_path(helpers.get_media_path(themes.get(theme,"adwaita_style.css")))
+
+        Gtk.StyleContext.add_provider_for_screen(
+            Gdk.Screen.get_default(), self.style_provider,
+            Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION
+        )
+
 
 
     def do_startup(self, *args, **kwargs):