vertical menubar: rewrite to make only menubar fixed positioned

This allows this style to work with several other styles such as
tabs_on_bottom.css

This patch also introduces a pref with which the side of the vertical
strip can be changed - the default is now on left

chrome/vertical_menubar.css

@@ -7,59 +7,80 @@ See the above repository for updates as well as full license text. */
 /* So, if you want the menu items to be toggleable, just move one button to be before menubar items in the toolbar. If all buttons come after menubar items, then none of those will trigger menubar items. */
 
 @-moz-document url(chrome://browser/content/browser.xhtml){
-
   :root{
     --uc-vertical-menubar-width: 36px;
   }
-  
-  :root:not([customizing]) #titlebar{
+  #toolbar-menubar{
+    --uc-vertical-menubar-top: 76px;
+    :root[uidensity="compact"] & {
+      --uc-vertical-menubar-top: 72px;
+    }
+  }
+  #navigator-toolbox:has(> #PersonalToolbar[collapsed="false"]) > #titlebar > #toolbar-menubar{
+    --uc-vertical-menubar-top: 112px;
+    :root[uidensity="compact"] & {
+      --uc-vertical-menubar-top: 94px;
+    } 
+  }
+  #titlebar{
+    opacity: 1 !important;
+    will-change: unset !important;
+  }
+  :root:not([customizing]) #toolbar-menubar{
     position: fixed;
-    display: flex;
-    z-index: 1;
-    -moz-appearance: none !important;
-    right: 0px; 
-    height: 100vh;
+    flex-direction: column;
+    top: var(--uc-vertical-menubar-top);
     width: var(--uc-vertical-menubar-width);
+    padding-top: 2px !important;
+    z-index: 2;
+    overflow: visible;
+    height: calc(100vh - var(--uc-vertical-menubar-top))
   }
-  :root:not([customizing]) #navigator-toolbox{ padding-top: calc(2* var(--tab-block-margin) + var(--tab-min-height)) }
-
-  #TabsToolbar:not([customizing]){
-    position: fixed;
-    display: flex;
-    top: 0px;
-    left: 0px;
-    width: 100vw;
+  :root[lwtheme] #toolbar-menubar{
+    background-color: var(--arrowpanel-background);
+  }
+  #main-menubar{
+    flex-direction: column;
+    align-self: flex-start;
+  }
+  #main-menubar{
+    outline: 1px solid var(--arrowpanel-border-color);
+    background-color: light-dark(rgb(235, 235, 239), rgb(31, 30, 37))
+  }
+  :root[lwtheme] #main-menubar{
+    background-color: var(--arrowpanel-background,var(--lwt-accent-color));
+  }
+  #toolbar-menubar > .titlebar-buttonbox-container{
+    display: none;
   }
-
-  :root[sizemode="normal"] :where(.titlebar-spacer){ display: flex !important; }
-  
-  #TabsToolbar > .toolbar-items{ max-width: calc(100vw - 138px); flex-grow: 1 }
   #TabsToolbar > .titlebar-buttonbox-container{
     display: flex !important;
   }
-
-  #toolbar-menubar:not([customizing]){
-    margin-top: 40px; /* This needs to be bigger if bookmarks toolbar is shown */
-    width: var(--uc-vertical-menubar-width);
-    flex-direction: column;
-    flex-grow: 1;
-    background-color: var(--lwt-accent-color);
+  :root:not([sizemode="fullscreen"]) :where(.titlebar-spacer[type="post-tabs"]),
+  :root[sizemode="normal"] :where(.titlebar-spacer){
+    display: flex !important;
   }
-
-  #toolbar-menubar > .titlebar-buttonbox-container,
-  #toolbar-menubar > spacer{ display: none !important; }
-
-  #toolbar-menubar > #menubar-items{ visibility: collapse }
   
+  #toolbar-menubar > #menubar-items{ visibility: collapse }
   #toolbar-menubar > .toolbarbutton-1:first-child:hover + #menubar-items,
   #toolbar-menubar > #menubar-items:hover{ visibility: visible }
-
-  #toolbar-menubar:not([customizing]) #main-menubar{
-    flex-direction: column;
-    margin-left: -40px;
-    background-color: var(--lwt-accent-color);
+  
+  :root:not([inDOMFullscreen]) #browser{
+    margin-left: var(--uc-vertical-menubar-width);
   }
 
-  :root:not([inDOMFullscreen]) #browser{ margin-right: var(--uc-vertical-menubar-width) }
-
+  @media (-moz-bool-pref: "userchrome.vertical-menubar.on-right.enabled"){
+    :root:not([inDOMFullscreen]) #browser{
+      margin-inline: 0 var(--uc-vertical-menubar-width);
+    }
+    #toolbar-menubar{
+      right: 0;
+    }
+    #toolbar-menubar:not([customizing]) #main-menubar{
+      align-self: flex-end;
+    }
+  }
+  :root[sizemode="fullscreen"] #browser{
+    margin-inline: 0;
+  }
 }