diff --git a/lib-core.sh b/lib-core.sh
index 72b9b96..7282d4a 100755
--- a/lib-core.sh
+++ b/lib-core.sh
@@ -29,6 +29,16 @@ else
   GNOME_VERSION="none"
 fi
 
+if command -v nautilus &> /dev/null; then
+  if (( $(nautilus --version | cut -d ' ' -f 3 | cut -d . -f 1) >= 40 )); then
+    NAUTILUS_VERSION="new"
+  else
+    NAUTILUS_VERSION="old"
+  fi
+else
+  NAUTILUS_VERSION="none"
+fi
+
 # Program options
 SASSC_OPT="-M -t expanded"
 
diff --git a/lib-install.sh b/lib-install.sh
index d75d479..1aa3941 100755
--- a/lib-install.sh
+++ b/lib-install.sh
@@ -519,10 +519,10 @@ customize_theme() {
   cp -rf "${THEME_SRC_DIR}/sass/_theme-options"{".scss","-temp.scss"}
 
   # Change common apps style for a specific GNOME Shell version
-  if [[ ${GNOME_VERSION} == "new" ]]; then
-    sed ${SED_OPT} "/\$gnome_version/s/old/new/"                    "${THEME_SRC_DIR}/sass/_theme-options-temp.scss"
-  elif [[ ${GNOME_VERSION} == "none" ]]; then
-    prompt -w "There's no GNOME Shell installed, using style for the older GNOME Shell instead..."
+  if [[ ${NAUTILUS_VERSION} == "new" ]]; then
+    sed ${SED_OPT} "/\$nautilus_version/s/old/new/"                    "${THEME_SRC_DIR}/sass/_theme-options-temp.scss"
+  elif [[ ${NAUTILUS_VERSION} == "none" ]]; then
+    prompt -w "There's no Nautilus installed, using style for the older gtk theme instead..."
   fi
 
   # Change gnome-shell panel transparency
diff --git a/src/sass/_theme-options.scss b/src/sass/_theme-options.scss
index 6f2a8ba..449c8fd 100644
--- a/src/sass/_theme-options.scss
+++ b/src/sass/_theme-options.scss
@@ -2,17 +2,14 @@
 // THEME OPTIONS
 //
 
-// Gnome shell version
-$gnome_version: 'old'; // 3.38/old || 40.0/new
-
-// Force nautilus styles to exclusively use colors instead of linear-gradients
-$nautilus_use_colors: false;
+// Nautilus version
+$nautilus_version: 'old'; // < 3.38/old || 40.0/new
 
 // Nautilus sidebar sizes (when nautilus_use_colors is false)
 $sidebar_size: 200px;
 
 // Nautilus style
-$nautilus_style: stable;
+$nautilus_style: 'stable';
 
 // Gnome-shell panel opacity
 $panel_opacity: 0.15;
diff --git a/src/sass/gnome-shell/common/_app-grid.scss b/src/sass/gnome-shell/common/_app-grid.scss
index 240e83f..320e062 100644
--- a/src/sass/gnome-shell/common/_app-grid.scss
+++ b/src/sass/gnome-shell/common/_app-grid.scss
@@ -49,7 +49,6 @@ $app_grid_fg_color: #fff;
   border-radius: $bd_radius * 4;
   border: 0 solid rgba(white, 0.15);
   padding: 12px;
-  background-color: rgba(black, 0.9);
 
   & .folder-name-container {
     padding: 24px 36px 0;
diff --git a/src/sass/gnome-shell/widgets-3-28/_app-grid.scss b/src/sass/gnome-shell/widgets-3-28/_app-grid.scss
index 64e3405..0af2195 100644
--- a/src/sass/gnome-shell/widgets-3-28/_app-grid.scss
+++ b/src/sass/gnome-shell/widgets-3-28/_app-grid.scss
@@ -27,6 +27,8 @@ $app_icon_padding: 24px;
 
 // expanded folder
 .app-folder-dialog {
+  background-color: rgba(#333, 0.9);
+
   & .page-indicators {
     .page-indicator {
       padding: 15px 12px;
diff --git a/src/sass/gnome-shell/widgets-40-0/_app-grid.scss b/src/sass/gnome-shell/widgets-40-0/_app-grid.scss
index cd2e392..10edae8 100644
--- a/src/sass/gnome-shell/widgets-40-0/_app-grid.scss
+++ b/src/sass/gnome-shell/widgets-40-0/_app-grid.scss
@@ -13,6 +13,10 @@ $app_icon_size: 96px;
   page-padding-right: $base_padding * 2;
 }
 
+.app-folder-dialog {
+  background-color: rgba(black, 0.9);
+}
+
 // App Grid pagination indicators
 .page-indicator {
   padding: $base_padding $base_padding * 2 0;
diff --git a/src/sass/gtk/_applications-3.0.scss b/src/sass/gtk/_applications-3.0.scss
index 7d5f7fc..4a62064 100644
--- a/src/sass/gtk/_applications-3.0.scss
+++ b/src/sass/gtk/_applications-3.0.scss
@@ -109,7 +109,7 @@ $nautilus_sidebar_image: image($dark_sidebar_bg);
 }
 
 @if $nautilus_style == 'stable' or $nautilus_style == 'default' {
-  @if $gnome_version == 'new' {
+  @if $nautilus_version == 'new' {
     $nautilus_header_image: linear-gradient(90deg, transparent $nautilus_sidebar_size,
                                                    $nautilus_borders_color $nautilus_sidebar_size,
                                                    $nautilus_borders_color ($nautilus_sidebar_size + 1px),
diff --git a/src/sass/gtk/_applications-4.0.scss b/src/sass/gtk/_applications-4.0.scss
index 73a08d6..1f33d14 100644
--- a/src/sass/gtk/_applications-4.0.scss
+++ b/src/sass/gtk/_applications-4.0.scss
@@ -69,7 +69,7 @@ $nautilus_sidebar_image: image($dark_sidebar_bg);
 }
 
 @if $nautilus_style == 'stable' or $nautilus_style == 'default' {
-  @if $gnome_version == 'new' {
+  @if $nautilus_version == 'new' {
     $nautilus_header_image: linear-gradient(90deg, transparent $nautilus_sidebar_size,
                                                    $nautilus_borders_color $nautilus_sidebar_size,
                                                    $nautilus_borders_color ($nautilus_sidebar_size + 1px),
diff --git a/src/sass/gtk/_common-3.0.scss b/src/sass/gtk/_common-3.0.scss
index a0b6864..c03882b 100644
--- a/src/sass/gtk/_common-3.0.scss
+++ b/src/sass/gtk/_common-3.0.scss
@@ -1378,7 +1378,8 @@ actionbar {
   border-top: 1px solid $borders_color;
   background-color: darken($bg_color, 3%);
 
-  .background.csd revealer > & {
+  .background.csd revealer > &,
+  .background.csd > box.vertical > & {
     border-radius: 0 0 $wm_radius $wm_radius;
   }
 }