Gadget-GlobalStyle.css

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/* CSS placed here will be applied to all skins on both desktop and mobile
   The "dark" and "mobile" body classes can be used to target different scenarios */

body.anon.ns-content.action-view.mobile #stub,
body.anon.ns-content.action-view .noticebox.nb-hide,
body.anon:not(.ns-10) .plainlinksneverexpand > * {
	display: none !important;
}
body.anon.ns-content.action-view:not(.mobile) .noticebox.nb-show {
	margin-top: 0 !important;
}

/* SiteNotice */
#localNotice a.external {
	padding: 0 !important;
	background: none !important;
}

/* Galleries */
.gallery.center {
	margin-left: auto !important;
	margin-right: auto !important;
}

/* Special:Preferences */
#mw-htmlform-mobile .oo-ui-inline-help {
	display: none;
}

/* Tabs fix */
.tabbox > .tab { margin-bottom: 8px; }
.tabbox:not(:first-of-type) { display: none; }

/* User profile */
.profile-icon {
	width: 22px;
	height: 22px;
	background-size: 22px;
	display: inline-block;
	vertical-align: middle;
	margin-right: 4px;
}
.user-section-heading { clear: both; }
@media all and (min-width: 720px) {
	#user-page-left > .profile-info-container > div {
		width: 50%;
		float: left;
	}
}
/* Edit profile */
body.mw-special-UpdateProfile .firstHeading {
	display: block;
}
body.mw-special-UpdateProfile #mw-content-text h1,
body.mw-special-UploadAvatar #mw-content-text h1 {
	display: none;
}

MediaWiki:Gadget-GlobalStyle.css