diff --git a/css/styles.css b/css/styles.css
index 6819a49c..7f0af224 100644
--- a/css/styles.css
+++ b/css/styles.css
@@ -18,6 +18,18 @@ radio {
 .gtk402 .osd trough highlight {
   border-color: inherit;
 }
+.adwrounded.csd {
+  border-radius: 8px;
+}
+.adwrounded.fullscreen,
+.adwrounded.maximized,
+.adwrounded.tiled,
+.adwrounded.tiled-top,
+.adwrounded.tiled-left,
+.adwrounded.tiled-right,
+.adwrounded.tiled-bottom {
+  border-radius: 0px;
+}
 
 .tvmode popover box {
   text-shadow: none;
diff --git a/src/appBase.js b/src/appBase.js
index bfd4fc39..4f8981c1 100644
--- a/src/appBase.js
+++ b/src/appBase.js
@@ -95,6 +95,12 @@ class ClapperAppBase extends Gtk.Application
         const theme = gtkSettings.gtk_theme_name;
         debug(`user selected theme: ${theme}`);
 
+        if(
+            theme.startsWith('Adwaita')
+            && !this.active_window.has_css_class('adwrounded')
+        )
+            this.active_window.add_css_class('adwrounded');
+
         if(!theme.endsWith('-dark'))
             return;