Added small theme demo.

scripts/theme_gallery.gd

@@ -0,0 +1,75 @@
+extends MarginContainer
+
+func _ready() -> void:
+	for side in ["left", "top", "right", "bottom"]:
+		add_theme_constant_override("margin_" + side, 24)
+	var scroll := ScrollContainer.new()
+	scroll.horizontal_scroll_mode = ScrollContainer.SCROLL_MODE_DISABLED
+	add_child(scroll)
+	var layout := VBoxContainer.new()
+	layout.size_flags_horizontal = Control.SIZE_EXPAND_FILL
+	layout.add_theme_constant_override("separation", 18)
+	scroll.add_child(layout)
+	var heading := Label.new()
+	heading.text = "SURFACESIDE / THEME GALLERY"
+	heading.add_theme_font_size_override("font_size", 28)
+	layout.add_child(heading)
+	var subtitle := Label.new()
+	subtitle.text = "Square corners · orange focus · plum accents · choose a theme below"
+	subtitle.autowrap_mode = TextServer.AUTOWRAP_WORD_SMART
+	layout.add_child(subtitle)
+	var picker := OptionButton.new()
+	picker.add_item("Soft / minimal borders")
+	picker.add_item("Original / high contrast")
+	picker.item_selected.connect(func(index: int) -> void:
+		theme = load("res://themes/theme.tres" if index == 0 else "res://themes/theme_highcontrast.tres")
+		for scope in get_tree().get_nodes_in_group("keyboard_focus_containers"):
+			if is_ancestor_of(scope):
+				scope._update_style()
+	)
+	layout.add_child(picker)
+	var panel := PanelContainer.new()
+	layout.add_child(panel)
+	var controls := VBoxContainer.new()
+	controls.add_theme_constant_override("separation", 16)
+	panel.add_child(controls)
+	var buttons := HFlowContainer.new()
+	buttons.add_theme_constant_override("h_separation", 12)
+	controls.add_child(buttons)
+	for state in ["Normal", "Toggle / pressed", "Disabled"]:
+		var button := Button.new()
+		button.text = state
+		button.toggle_mode = state == "Toggle / pressed"
+		button.button_pressed = button.toggle_mode
+		button.disabled = state == "Disabled"
+		buttons.add_child(button)
+	var option := OptionButton.new()
+	option.add_item("Primary display")
+	option.add_item("Secondary display")
+	buttons.add_child(option)
+	var check := CheckBox.new()
+	check.text = "Telemetry enabled"
+	check.button_pressed = true
+	controls.add_child(check)
+	var input := LineEdit.new()
+	input.placeholder_text = "Command input — Tab to inspect focus"
+	controls.add_child(input)
+	var text := TextEdit.new()
+	text.custom_minimum_size.y = 110
+	text.text = "Operator notes\nSelect text to inspect the selection color."
+	controls.add_child(text)
+	var slider := HSlider.new()
+	slider.value = 65
+	controls.add_child(slider)
+	var progress := ProgressBar.new()
+	progress.value = 65
+	controls.add_child(progress)
+	slider.value_changed.connect(func(value: float) -> void: progress.value = value)
+	var tabs := TabContainer.new()
+	tabs.custom_minimum_size.y = 100
+	controls.add_child(tabs)
+	for title in ["Status", "Diagnostics"]:
+		var label := Label.new()
+		label.name = title
+		label.text = "  " + title + " / All systems ready"
+		tabs.add_child(label)