Story Viewer: add translucent background behind title

data/gui/widget/label_story_screen_title.cfg

@@ -0,0 +1,90 @@
+#textdomain wesnoth-lib
+###
+### Definition of the title label for the story viewer.
+###
+
+[label_definition]
+	id = "story_screen_title"
+	description = "Large label with translucent background for story screen"
+
+	[resolution]
+		{GUI_NORMAL__RESOLUTION}
+
+		min_width = 0
+		min_height = 0
+
+		default_width = 0
+		default_height = 50
+
+		max_width = 0
+		max_height = 0
+
+		text_font_size = {GUI_FONT_SIZE_LARGE}
+
+		link_aware = false
+
+		[state_enabled]
+
+			[draw]
+
+				[rectangle]
+					x = 0
+					y = 0
+					w = "(width)"
+					h = "(height)"
+					fill_color = "0, 0, 0, 128"
+				[/rectangle]
+
+				[text]
+					x = 20
+					y = {GUI__TEXT_VERTICALLY_CENTRED}
+					w = "(width)"
+					h = "(text_height)"
+					maximum_width = "(width)"
+					font_size = {GUI_FONT_SIZE_LARGE}
+					color = {GUI__FONT_COLOR_ENABLED__DEFAULT}
+					text = "(text)"
+					text_markup = "(text_markup)"
+					text_alignment = "(text_alignment)"
+					text_link_aware = "(text_link_aware)"
+					text_link_color = "(text_link_color)"
+				[/text]
+
+			[/draw]
+
+		[/state_enabled]
+
+		[state_disabled]
+
+			[draw]
+
+				[rectangle]
+					x = 0
+					y = 0
+					w = "(width)"
+					h = "(height)"
+					fill_color = "0, 0, 0, 128"
+				[/rectangle]
+
+				[text]
+					x = 20
+					y = {GUI__TEXT_VERTICALLY_CENTRED}
+					w = "(width)"
+					h = "(text_height)"
+					maximum_width = "(width)"
+					font_size = {GUI_FONT_SIZE_LARGE}
+					color = {GUI__FONT_COLOR_DISABLED__DEFAULT}
+					text = "(text)"
+					text_markup = "(text_markup)"
+					text_alignment = "(text_alignment)"
+					text_link_aware = "(text_link_aware)"
+					text_link_color = "(text_link_color)"
+				[/text]
+
+			[/draw]
+
+		[/state_disabled]
+
+	[/resolution]
+
+[/label_definition]

data/gui/window/story_viewer.cfg

@@ -212,13 +212,15 @@
 
 				[column]
 					grow_factor = 1
-					border = "all"
-					border_size = 20
+
+					# No borders intentionally so the label covers the entire area.
+					# Offsets are handled in the definition.
+
 					horizontal_grow = true
 					vertical_grow = true
 
 					[label]
-						definition = "default_large"
+						definition = "story_screen_title"
 						id = "title"
 						label = "Placeholder text"
 						use_markup = true