General Discussion • please help me with my user chrome file

CODE:

/* Force bookmark drop-down button display even with classic menu bar */#bookmarks-menu-button {display:-moz-box !important}/* Bookmark This Page */#appmenu_bookmarkThisPage,#menu_bookmarkThisPage,#BMB_bookmarkThisPage{ display: none !important; }/* Subscribe to This Page */#appmenu_subscribeToPage,#appmenu_subscribeToPageMenu,#appmenu_subscribeToPageMenu + menuseparator,#subscribeToPageMenuitem,#subscribeToPageMenupopup,#menu_bookmarkAllTabs, /* show-only-for-keyboard */#menu_bookmarkAllTabs + menuseparator,#BMB_subscribeToPageMenuitem,#BMB_subscribeToPageMenupopup,#BMB_subscribeToPageMenupopup + menuseparator{ display: none !important; }#nav-bar[tabsontop=true],#nav-bar[tabsontop=true][collapsed=true]:not([customizing]) + toolbar,#nav-bar[tabsontop=true][collapsed=true]:not([customizing]) + #customToolbars + #PersonalToolbar {  background-image: linear-gradient(rgba(255,255,255,.5), rgba(255,255,255,0)) !important;}