Allow disabling styling of fake nanoui windows

code/datums/browser.dm

@@ -28,6 +28,9 @@
 		height = nheight
 	if (nref)
 		ref = nref
+	// If a client exists, but they have disabled fancy windowing, disable it!
+	if(user && user.client && !user.client.is_preference_enabled(/datum/client_preference/browser_style))
+		return
 	add_stylesheet("common", 'html/browser/common.css') // this CSS sheet is common to all UIs
 
 /datum/browser/proc/set_title(ntitle)
@@ -178,4 +181,4 @@
 	if(src && src.mob)
 		//world << "[src] was [src.mob.machine], setting to null"
 		src.mob.unset_machine()
-	return
+	return

code/modules/client/preference_setup/global/setting_datums.dm

@@ -137,6 +137,13 @@ var/list/_client_preferences_by_type
 	key = "SAFE_FIRING"
 	enabled_description = "Safe"
 	disabled_description = "Dangerous"
+
+/datum/client_preference/browser_style
+	description = "Fake NanoUI Browser Style"
+	key = "BROWSER_STYLED"
+	enabled_description = "Fancy"
+	disabled_description = "Plain"
+
 /********************
 * Staff Preferences *
 ********************/