GTK3: Custom placessidebar for Nautilus

src/themes/Kali/sass/gtk-sass/_applications.scss

@@ -7,6 +7,49 @@ $panel_bg : transparentize($bg_color, if($variant=='light', .1, .2));
 @define-color disk_space_used #{"" +$selected_bg_color};
 @define-color disk_space_free white;
 
+filechooser,
+.nautilus-window {
+  placessidebar.sidebar {
+    box-shadow: inset 0 8px 4px -8px transparentize(black, .7);
+
+    &:dir(ltr) {
+      background-image: linear-gradient(to right, darken($bg_color, 4%) 41px, $bg_color 0);
+    }
+    &:dir(rtl) {
+      background-image: linear-gradient(to left, darken($bg_color, 4%) 41px, $bg_color 0);
+    }
+
+    &:backdrop { box-shadow: none; }
+
+    row.sidebar-row {
+      &:selected {
+        @extend %selected_items;
+
+        margin-left: 6px;
+        margin-right: 6px;
+        border-radius: $button_radius;
+        box-shadow: 0 2px 4px transparentize($selected_bg_color, .5);
+
+        &:dir(ltr) {
+          background-image: linear-gradient(to right, darken($selected_bg_color, 10%) 35px, transparent 0);
+        }
+        &:dir(rtl) {
+          background-image: linear-gradient(to left, darken($selected_bg_color, 10%) 35px, transparent 0);
+        }
+
+        revealer {
+          padding-left: 8px;
+          padding-right: 8px;
+
+          .sidebar-icon, .sidebar-label { color: white; }
+        }
+      }
+
+      .sidebar-icon { padding-right: 20px; }
+    }
+  }
+}
+
 /* XFCE4 PANEL */
 .xfce4-panel {
   &.background { background: $panel_bg; }

src/themes/Kali/sass/gtk-sass/_common-tweaks.scss

@@ -259,6 +259,23 @@ infobar {
  ***********/
 messagedialog .titlebar:backdrop { background-image: none; }
 
+
+/***********
+ * Sidebar *
+ ***********/
+.sidebar {
+  background-color: $bg_color;
+}
+
+/****************
+ * File chooser *
+ ****************/
+placessidebar {
+  row {
+    min-height: 30px;
+  }
+}
+
 /**********************
  * Window Decorations *
  *********************/