diff --git a/firefox/userChrome.css b/firefox/userChrome.css
deleted file mode 100644
index dc5b0f6..0000000
--- a/firefox/userChrome.css
+++ /dev/null
@@ -1,45 +0,0 @@
-/* Hide main tabs toolbar */
-#main-window[tabsintitlebar="true"]:not([extradragspace="true"]) #TabsToolbar > .toolbar-items {
-    opacity: 0;
-    pointer-events: none;
-}
-#main-window:not([tabsintitlebar="true"]) #TabsToolbar {
-    visibility: collapse !important;
-}
-
-/* Sidebar min and max width removal */
-#sidebar {
-    max-width: none !important;
-    min-width: 0px !important;
-}
-/* Hide splitter, when using Tree Style Tab. */
-#sidebar-box[sidebarcommand="treestyletab_piro_sakura_ne_jp-sidebar-action"] + #sidebar-splitter {
-    display: none !important;
-}
-/* Hide sidebar header, when using Tree Style Tab. */
-#sidebar-box[sidebarcommand="treestyletab_piro_sakura_ne_jp-sidebar-action"] #sidebar-header {
-    visibility: collapse;
-}
-
-/* Shrink sidebar until hovered, when using Tree Style Tab. */
-:root {
-    --thin-tab-width: 30px;
-    --wide-tab-width: 200px;
-}
-#sidebar-box:not([sidebarcommand="treestyletab_piro_sakura_ne_jp-sidebar-action"]) {
-    min-width: var(--wide-tab-width) !important;
-    max-width: none !important;
-}
-#sidebar-box[sidebarcommand="treestyletab_piro_sakura_ne_jp-sidebar-action"] {
-    position: relative !important;
-    transition: all 100ms !important;
-    min-width: var(--thin-tab-width) !important;
-    max-width: var(--thin-tab-width) !important;
-}
-#sidebar-box[sidebarcommand="treestyletab_piro_sakura_ne_jp-sidebar-action"]:hover {
-    transition: all 200ms !important;
-    min-width: var(--wide-tab-width) !important;
-    max-width: var(--wide-tab-width) !important;
-    margin-right: calc((var(--wide-tab-width) - var(--thin-tab-width)) * -1) !important;
-    z-index: 1;
-}