Show panel and website controls for website side panels

src/toolkit/content/zen-fullscreen-override.css

@@ -1,5 +1,6 @@
 
-[inDOMFullscreen="true"] #nav-bar {
+[inDOMFullscreen="true"] #nav-bar,
+[inDOMFullscreen="true"] #zen-sidebar-web-panel {
   display: none !important;
 }
 

src/toolkit/content/zen-xul.css

@@ -7,6 +7,7 @@
   --zen-appcontent-separator-from-window: var(--zen-appcontent-separator-from-window-single);
   --zen-appcontent-border-radius: var(--zen-panel-radius);
   --zen-appcontent-border: 1px solid light-dark(#ddd, #4a4a4a);
+  --zen-browser-border-radius: 10px;
 }
 
 toolbox#navigator-toolbox, 
@@ -28,6 +29,10 @@ html#main-window > body {
   margin: var(--zen-appcontent-separator-from-window);
 }
 
+#appcontent[inlinedwithsidebar="true"] {
+  background: var(--toolbar-bgcolor);
+}
+
 :not([inDOMFullscreen="true"]) #appcontent,
 #sidebar-box,
 #navigator-toolbox:not([inlinedwithsidebar="true"]) #TabsToolbar {

src/toolkit/themes/shared/zen-popup.css

@@ -243,6 +243,7 @@ toolbarbutton:not(:is(
   .zen-sidebar-action-button, 
   .all-tabs-close-button,
   .zen-sidebar-panel-button,
+  #zen-sidebar-web-panel-close,
   #PanelUI-zen-profiles-managePrfs
 )),
 #PanelUI-zen-profiles menuitem {