diff --git a/src/sass/_variables.scss b/src/sass/_variables.scss
index 6e6a810d..d87455b6 100644
--- a/src/sass/_variables.scss
+++ b/src/sass/_variables.scss
@@ -79,7 +79,7 @@ $backdrop_transition: $longer_duration ease-out;
 // Shadow
 $shadow_0: 0 1px 2px 0 rgba(black, 0.1), 0 2px 2px 0 rgba(black, 0.05);     // Slider hover shadow
 $shadow_1: 0 1px 1px 0 rgba(black, 0.12), 0 1px 2px 0 rgba(black, 0.06);    // Header-button shadow
-$shadow_2: 0 1px 1px 0 rgba(black, 0.1), 0 1px 2px 0 rgba(black, 0.05);     // Slider normal shadow
+$shadow_2: 0 1px 1px 0 rgba(black, 0.03), 0 1px 2px 0 rgba(black, 0.08);     // Slider normal shadow
 $shadow_3: 0 1px 1px 0 rgba(black, 0.03), 0 1px 2px 0 rgba(black, 0.01);    // Normal button shadow
 $shadow_4: 0 2px 3px 0 rgba(black, 0.2), 0 3px 5px 0 rgba(black, 0.15);     // Switch-slider hover shadow
 $shadow_5: 0 1px 2px 0 rgba(black, 0.15), 0 2px 3px 0 rgba(black, 0.1);     // Switch-slider normal shadow
diff --git a/src/sass/gtk/_common-3.0.scss b/src/sass/gtk/_common-3.0.scss
index 16ce4126..047e3708 100644
--- a/src/sass/gtk/_common-3.0.scss
+++ b/src/sass/gtk/_common-3.0.scss
@@ -670,7 +670,7 @@ $_dot_color: $selected_bg_color;
 %circular_button {
   border-radius: $circular_radius;
   -gtk-outline-radius: $circular_radius;
-  padding: 0 0;
+  padding: 0;
   min-height: $menuitem_size;
   min-width: $menuitem_size;
 }
@@ -2196,7 +2196,6 @@ menubar,
 menu,
 .menu,
 .context-menu {
-  // margin: 4px;
   padding: $container_padding;
   border-radius: $mn_radius;
   background-color: opacify($menu_bg, 1);
@@ -2295,23 +2294,19 @@ menu,
     min-height: 16px;
     padding: 2px;
     background-color: transparent;
-    border-radius: 0;
+    border-radius: $mn_radius - 3px;
     border: none;
     background-image: none;
     color: $fg_color;
 
     &.top {
-      margin-top: -6px;
-      border-radius: $mn_radius $mn_radius 0 0;
-      border-bottom: 1px solid $borders_color;
+      margin-top: 0;
       -gtk-icon-source: -gtk-icontheme('pan-up-symbolic');
     }
 
     &.bottom {
       margin-top: 12px;
-      margin-bottom: -16px;
-      border-radius: 0 0 $mn_radius $mn_radius;
-      border-top: 1px solid $borders_color;
+      margin-bottom: -12px;
       -gtk-icon-source: -gtk-icontheme('pan-down-symbolic');
     }
 
@@ -3065,24 +3060,23 @@ scale {
   }
 
   slider {
-    $_slider_border: if($variant=='light', transparentize(darken($button_border, 0%), 0), transparentize($button_border, 0));
+    $_slider_border: $button_border;
 
     background-color: $selected_fg_color;
     border: 1px solid $_slider_border;
     border-radius: 100%;
     box-shadow: $shadow_2;
-
+    background-clip: padding-box;
     transition: $button_transition;
     transition-property: background, border;
 
     &:hover {
-        background-color: lighten($selected_fg_color, 3%);
-        border-color: $_slider_border;
-        box-shadow: $shadow_0;
-      }
+      background-color: lighten($selected_fg_color, 3%);
+      border-color: $_slider_border;
+      box-shadow: $shadow_0;
+    }
 
     &:active {
-      background-clip: border-box;
       background-color: $selected_fg_color;
       border-color: $_slider_border;
       box-shadow: $shadow_3;
@@ -3563,6 +3557,7 @@ row {
 
   button {
     @extend %undecorated_button;
+    @include button(flat-normal);
 
     &:not(.text-button).image-button, &.flat {
       @extend %circular_button;
diff --git a/src/sass/gtk/apps/_gnome-3.22.scss b/src/sass/gtk/apps/_gnome-3.22.scss
index ac431f85..7f911c37 100644
--- a/src/sass/gtk/apps/_gnome-3.22.scss
+++ b/src/sass/gtk/apps/_gnome-3.22.scss
@@ -2957,6 +2957,12 @@ window.background.csd {
   }
 }
 
+.app-notification.boxes-toast {
+  > button.circular.flat {
+    padding: 2px;
+  }
+}
+
 //
 // Dialogs
 //
diff --git a/src/sass/gtk/apps/_misc.scss b/src/sass/gtk/apps/_misc.scss
index ff802fb6..e668b624 100644
--- a/src/sass/gtk/apps/_misc.scss
+++ b/src/sass/gtk/apps/_misc.scss
@@ -91,7 +91,7 @@ window.background:not(.csd) {
 
     > radio,
     > check {
-      padding: 0;
+      padding: 1px;
     }
   }
 
diff --git a/tweaks.sh b/tweaks.sh
index 5411a34c..a79d9035 100755
--- a/tweaks.sh
+++ b/tweaks.sh
@@ -96,7 +96,7 @@ while [[ $# -gt 0 ]]; do
         esac
       done
 
-      if ! has_command firefox && ! has_command firefox-bin && ! has_flatpak_app org.mozilla.firefox && ! has_snap_app firefox; then
+      if ! has_command firefox && ! has_command firefox-bin && ! has_flatpak_app org.mozilla.firefox && ! has_snap_app firefox && ! has_command firefox-developer-edition; then
         prompt -e "'${1}' ERROR: There's no Firefox installed in your system"
         has_any_error="true"
       elif [[ ! -d "${FIREFOX_DIR_HOME}" && ! -d "${FIREFOX_FLATPAK_DIR_HOME}" && ! -d "${FIREFOX_SNAP_DIR_HOME}" ]]; then