diff --git a/defaults/xdg/dunst/dunstrc b/defaults/xdg/dunst/dunstrc
index 0b87722..0a83093 100644
--- a/defaults/xdg/dunst/dunstrc
+++ b/defaults/xdg/dunst/dunstrc
@@ -124,7 +124,7 @@
 
     ### Text ###
 
-    font = JetBrainsMono Nerd Font 10
+    font = UbuntuSans Nerd Font 10
 
     # The spacing between lines.  If the height is smaller than the
     # font height, it will get raised to the font height.
diff --git a/defaults/xdg/foot/foot.ini b/defaults/xdg/foot/foot.ini
index bd36abb..c10b050 100644
--- a/defaults/xdg/foot/foot.ini
+++ b/defaults/xdg/foot/foot.ini
@@ -10,7 +10,7 @@
 # title=foot
 # locked-title=no
 
-font=Hack Nerd Font:size=11
+font=UbuntuSans Nerd Font:size=11
 # font-bold=<bold variant of regular font>
 # font-italic=<italic variant of regular font>
 # font-bold-italic=<bold+italic variant of regular font>
diff --git a/defaults/xdg/gtk-3.0/settings.ini b/defaults/xdg/gtk-3.0/settings.ini
index 9340092..03bfbef 100644
--- a/defaults/xdg/gtk-3.0/settings.ini
+++ b/defaults/xdg/gtk-3.0/settings.ini
@@ -2,9 +2,9 @@
 # ABOUTME: User overrides go in ~/.config/gtk-3.0/settings.ini
 
 [Settings]
-gtk-theme-name=catppuccin-mocha-lavender-standard+default
+gtk-theme-name=Colloid-Catppuccin
 gtk-icon-theme-name=Newaita-reborn-gray-dark
-gtk-font-name=Hack Nerd Font 11
+gtk-font-name=UbuntuSans Nerd Font 11
 gtk-cursor-theme-name=Sweet-cursors
 gtk-cursor-theme-size=24
 gtk-toolbar-style=GTK_TOOLBAR_BOTH
diff --git a/defaults/xdg/rofi/bluetooth/bluetooth.rasi b/defaults/xdg/rofi/bluetooth/bluetooth.rasi
index 919ab36..08c2286 100644
--- a/defaults/xdg/rofi/bluetooth/bluetooth.rasi
+++ b/defaults/xdg/rofi/bluetooth/bluetooth.rasi
@@ -112,7 +112,7 @@ textbox-prompt-colon {
     enabled:                     true;
     padding:                     5px 0px 0px 15px;
     expand:                      false;
-    font:                        "MonarchOS 14";
+    font:                        "UbuntuSans Nerd Font 14";
     str:                         "";
     background-color:            inherit;
     text-color:                  inherit;
diff --git a/defaults/xdg/rofi/config.rasi b/defaults/xdg/rofi/config.rasi
index dc914d9..cb2b32f 100644
--- a/defaults/xdg/rofi/config.rasi
+++ b/defaults/xdg/rofi/config.rasi
@@ -52,7 +52,7 @@ configuration {
     alternate-active-background: var(active);
     alternate-active-foreground: var(background);
 
-    font: "JetBrainsMono Nerd Font 11";
+    font: "UbuntuSans Nerd Font 11";
     border-radius: 4px;
     frame-border: 1px solid;
 }
@@ -287,7 +287,7 @@ textbox {
     border-radius:               0 0 0 0;
     border-color:                @borders;
     background-color:            transparent;
-    font:                        "JetBrainsMono Nerd Font 12";
+    font:                        "UbuntuSans Nerd Font 12";
     text-color:                  var(theme-text-color);
     horizontal-align:            0.5;
     highlight:                   none;
diff --git a/defaults/xdg/rofi/emojis/emojis.rasi b/defaults/xdg/rofi/emojis/emojis.rasi
index b81d555..703d4c9 100644
--- a/defaults/xdg/rofi/emojis/emojis.rasi
+++ b/defaults/xdg/rofi/emojis/emojis.rasi
@@ -96,7 +96,7 @@ textbox-prompt-colon {
     enabled:                     true;
     padding:                     5px 0px 0px 15px;
     expand:                      false;
-    font:                        "MonarchOS 14";
+    font:                        "UbuntuSans Nerd Font 14";
     str:                         "";
     background-color:            inherit;
     text-color:                  inherit;
diff --git a/defaults/xdg/rofi/helper/rofi-bangs.rasi b/defaults/xdg/rofi/helper/rofi-bangs.rasi
index 96fa1b1..5eecd4c 100644
--- a/defaults/xdg/rofi/helper/rofi-bangs.rasi
+++ b/defaults/xdg/rofi/helper/rofi-bangs.rasi
@@ -108,7 +108,7 @@ textbox-prompt-colon {
     enabled:                     true;
     padding:                     5px 0px 0px 15px;
     expand:                      false;
-    font:                        "MonarchOS 14";
+    font:                        "UbuntuSans Nerd Font 14";
     str:                         "";
     background-color:            inherit;
     text-color:                  inherit;
diff --git a/defaults/xdg/rofi/powermenu/confirm.rasi b/defaults/xdg/rofi/powermenu/confirm.rasi
index 89f2670..016d390 100644
--- a/defaults/xdg/rofi/powermenu/confirm.rasi
+++ b/defaults/xdg/rofi/powermenu/confirm.rasi
@@ -30,7 +30,7 @@ textbox {
 
     placeholder-color:           var(theme-text-color);
 
-    font: "JetBrainsMono Nerd Font Bold 12";
+    font: "UbuntuSans Nerd Font Bold 12";
 }
 error-message {
     padding:                     12px;
@@ -64,7 +64,7 @@ element-text {
     cursor:                      inherit;
     horizontal-align: 0.5;
     vertical-align:0;
-    font:                        "JetBrainsMono Nerd Font 18";
+    font:                        "UbuntuSans Nerd Font 18";
 
 }
 element selected.normal  {
diff --git a/defaults/xdg/rofi/powermenu/powermenu.rasi b/defaults/xdg/rofi/powermenu/powermenu.rasi
index c75bcd7..22e24a7 100644
--- a/defaults/xdg/rofi/powermenu/powermenu.rasi
+++ b/defaults/xdg/rofi/powermenu/powermenu.rasi
@@ -41,7 +41,7 @@ textbox-prompt-colon {
     str:                         "󰣇";
     margin: 0;
     padding:                     0 4px 0 0;
-    font:                        "JetBrainsMono Nerd Font 16";
+    font:                        "UbuntuSans Nerd Font 16";
 }
 prompt {
     padding: 4px 0 0 0;
@@ -86,7 +86,7 @@ element {
     cursor:                      "pointer";
 }
 element-text {
-    font:                        "JetBrainsMono Nerd Font 28";
+    font:                        "UbuntuSans Nerd Font 28";
     background-color:            transparent;
     text-color:                  var(text);
     cursor:                      inherit;
diff --git a/defaults/xdg/rofi/settings-menu/settings-menu.rasi b/defaults/xdg/rofi/settings-menu/settings-menu.rasi
index 95d1e03..d811cca 100644
--- a/defaults/xdg/rofi/settings-menu/settings-menu.rasi
+++ b/defaults/xdg/rofi/settings-menu/settings-menu.rasi
@@ -22,5 +22,5 @@ element-icon {
 element-text {
     vertical-align:              0.5;
     horizontal-align:            0.5;
-    font: "JetBrainsMono Nerd Font 9";
+    font: "UbuntuSans Nerd Font 9";
 }
diff --git a/defaults/xdg/rofi/volume/-volume.rasi b/defaults/xdg/rofi/volume/-volume.rasi
index 7c543f5..83798e5 100644
--- a/defaults/xdg/rofi/volume/-volume.rasi
+++ b/defaults/xdg/rofi/volume/-volume.rasi
@@ -163,7 +163,7 @@ element {
     cursor:                      pointer;
 }
 element-text {
-    font:                        "JetBrainsMono Nerd Font bold 32";
+    font:                        "UbuntuSans Nerd Font Bold 32";
     background-color:            transparent;
     text-color:                  inherit;
     cursor:                      inherit;
diff --git a/defaults/xdg/waybar/style.css b/defaults/xdg/waybar/style.css
index 6429bb1..74049be 100644
--- a/defaults/xdg/waybar/style.css
+++ b/defaults/xdg/waybar/style.css
@@ -3,7 +3,7 @@
 
 * {
     border: none;
-    font-family: "Ubuntu Nerd Font", sans-serif;
+    font-family: "UbuntuSans Nerd Font", sans-serif;
     font-size: 13px;
     color: alpha(@theme_text_color, 0.8);
 }
diff --git a/packages/aur.txt b/packages/aur.txt
index 18952e0..08179e7 100644
--- a/packages/aur.txt
+++ b/packages/aur.txt
@@ -5,8 +5,8 @@
 # paru
 
 # Theming
-catppuccin-gtk-theme-mocha
-newaita-reborn-icons-git
+colloid-catppuccin-gtk-theme-git
+colloid-catppuccin-theme-git
 
 # Niri / Wayland Extras
 rofi-lbonn-wayland-git
diff --git a/packages/official.txt b/packages/official.txt
index ab4ee69..8fa0f48 100644
--- a/packages/official.txt
+++ b/packages/official.txt
@@ -77,7 +77,7 @@ xdg-desktop-portal-gtk
 qt6-5compat
 
 # Themes & Fonts
-ttf-hack-nerd
+ttf-ubuntusans-nerd
 
 # Anwendungen
 viewnior
diff --git a/scripts/post-install.sh b/scripts/post-install.sh
index 0cbdc0a..e6f1cac 100755
--- a/scripts/post-install.sh
+++ b/scripts/post-install.sh
@@ -83,6 +83,34 @@ sudo cp -r "$DEFAULTS_DIR/xdg/"* /etc/xdg/
 # Sicherstellen dass Rofi-Scripts ausführbar sind
 sudo find /etc/xdg/rofi -name "*.sh" -exec chmod +x {} \;
 
+# --- GTK4 Theme-Symlinks für libadwaita-Apps ---
+
+THEME_NAME="Colloid-Catppuccin"
+THEME_GTK4="/usr/share/themes/$THEME_NAME/gtk-4.0"
+GTK4_XDG="/etc/xdg/gtk-4.0"
+
+if [[ -d "$THEME_GTK4" ]]; then
+    log "Erstelle systemweite GTK4-Symlinks für $THEME_NAME..."
+
+    # gtk.css zeigt auf gtk-dark.css, damit libadwaita-Apps das Dark-Theme laden
+    sudo ln -sf "$THEME_GTK4/gtk-dark.css" "$GTK4_XDG/gtk.css"
+    sudo ln -sf "$THEME_GTK4/gtk-dark.css" "$GTK4_XDG/gtk-dark.css"
+
+    # Assets-Symlink: erst entfernen falls vorhanden (ln -sf auf Verzeichnisse folgt dem Link)
+    sudo rm -f "$GTK4_XDG/assets"
+    sudo ln -s "$THEME_GTK4/assets" "$GTK4_XDG/assets"
+else
+    err "GTK4-Theme nicht gefunden: $THEME_GTK4 — libadwaita-Apps nutzen Fallback-Theme."
+fi
+
+# --- gsettings für GTK-Theme und Dark-Mode ---
+
+log "Setze gsettings für GTK-Theme..."
+gsettings set org.gnome.desktop.interface gtk-theme "$THEME_NAME"
+gsettings set org.gnome.desktop.interface color-scheme 'prefer-dark'
+gsettings set org.gnome.desktop.interface icon-theme 'Colloid-Grey-Catppuccin-Dark'
+gsettings set org.gnome.desktop.interface font-name 'UbuntuSans Nerd Font 11'
+
 # --- Helper-Scripts installieren ---
 
 log "Installiere Moonarch Helper-Scripts nach /usr/local/bin/..."