Move "legacy" or otherwise deprecated styles into sub-folder

chrome/deprecated/theme_sidebar.css

@@ -0,0 +1,46 @@
+/* Source file https://github.com/MrOtherGuy/firefox-csshacks/tree/master/chrome/theme_sidebar.css made available under Mozilla Public License v. 2.0
+See the above repository for updates as well as full license text. */
+
+/* Colors for bookmarks and history sidebars */
+/* Color editing should generally be done in theme_color_variables.css */
+
+/*!!! IMPORT theme_color_variables.css !!!*/
+
+#sidebar-box{ --toolbar-non-lwt-bgcolor: var(--uc-light-bkgnd-color) }
+
+#sidebar-search-container #search-box{
+  -moz-appearance:none !important;
+  background-color: var(--uc-dark-bkgnd-color) !important;
+  border: none !important;
+  color: var(--uc-text-color) !important;
+}
+
+#history-panel,
+#bookmarksPanel,
+#sidebar-header{
+  background-color: var(--uc-light-bkgnd-color) !important;
+  color: var(--uc-text-color) !important;
+  border-top: none !important;
+  border-bottom:none !important;
+  scrollbar-color: rgb(210,210,210) var(--uc-light-bkgnd-color) !important;
+}
+
+.sidebar-placesTreechildren,
+#sidebar-box,
+#sidebar-header{
+  color: var(--uc-text-color) !important;
+}
+
+.sidebar-placesTreechildren::-moz-tree-cell{
+  outline:none;
+  border-radius:0px;
+  background-image:none;
+}
+
+.sidebar-placesTreechildren::-moz-tree-cell(selected){
+  background-color: var(--uc-border-color) !important;
+}
+
+.sidebar-placesTreechildren::-moz-tree-cell(hover){
+  background-color: var(--uc-active-color) !important;
+}