Localize the config

src/main/java/com/cleanroommc/modularui/ModularUIConfig.java

@@ -7,43 +7,55 @@
 @Config(modid = ModularUI.ID)
 public class ModularUIConfig {
 
+    @Config.LangKey("modularui2.config.default_scroll_speed")
     @Config.Comment("Amount of pixels scrolled")
     @Config.RangeInt(min = 1, max = 100)
     public static int defaultScrollSpeed = 30;
 
+    @Config.LangKey("modularui2.config.smooth_progress_bar")
     @Config.Comment("If progress bar should step in texture pixels or screen pixels. (Screen pixels are way smaller and therefore smoother)")
     public static boolean smoothProgressBar = false;
 
     // Default direction
+    @Config.LangKey("modularui2.config.tooltip_pos")
     @Config.Comment("Default tooltip position around the widget or its panel.")
     public static RichTooltip.Pos tooltipPos = RichTooltip.Pos.NEXT_TO_MOUSE;
 
+    @Config.LangKey("modularui2.config.esc_restore_last_text")
     @Config.Comment("If true, pressing ESC key in the text field will restore the last text instead of confirming current one.")
     public static boolean escRestoreLastText = false;
 
+    @Config.LangKey("modularui2.config.show_slot_overlay")
     @Config.Comment("If true, display the slot overlay when the slot is occupied.")
     public static boolean showSlotOverlay = true;
 
+    @Config.LangKey("modularui2.config.gui_debug_mode")
     @Config.Comment("If true, widget outlines and widget information will be drawn.")
     public static boolean guiDebugMode = ModularUI.isDevEnv;
 
+    @Config.LangKey("modularui2.config.use_dark_theme_by_default")
     @Config.Comment("If true and not specified otherwise, screens will try to use the 'vanilla_dark' theme.")
     public static boolean useDarkThemeByDefault = false;
 
+    @Config.LangKey("modularui2.config.debug_text_color")
     @Config.Comment("Debug text color. Prefix Hex values with a #. Common colors can be referred by their name.")
     public static String debugTextColor = "#FFAAAAAA";
 
+    @Config.LangKey("modularui2.config.debug_outline_color")
     @Config.Comment("Debug outline color. Prefix Hex values with a #. Common colors can be referred by their name.")
     public static String debugOutlineColor = "#DCB42873";
 
+    @Config.LangKey("modularui2.config.enable_test_guis")
     @Config.RequiresMcRestart
     @Config.Comment("Enables a test block, test item with a test gui and opening a gui by right clicking a diamond.")
     public static boolean enableTestGuis = ModularUI.isDevEnv;
 
+    @Config.LangKey("modularui2.config.enable_test_overlays")
     @Config.RequiresMcRestart
     @Config.Comment("Enables a test overlay shown on title screen and watermark shown on every GuiContainer.")
     public static boolean enableTestOverlays = false;
 
+    //@Config.LangKey("modularui2.config.use_rich_tooltips")
     //@Config.Comment("If true, vanilla tooltip will be replaced with MUI's RichTooltip")
     //public static boolean replaceVanillaTooltips = false;
 }

src/main/resources/assets/modularui2/lang/en_US.lang

@@ -37,3 +37,29 @@ modularui2.debug.slot_number=§7Slot Number: §3%d
 modularui2.debug.shift_click_priority=§7Shift-Click Priority: §3%d
 modularui2.debug.disabled=§cDISABLED
 modularui2.debug.hovered=§7Hovered: §6%s
+
+# Config
+modularui2.config.default_scroll_speed=Scroll Speed
+modularui2.config.default_scroll_speed.tooltip=Amount of pixels scrolled
+modularui2.config.smooth_progress_bar=Smooth Progress Bar
+modularui2.config.smooth_progress_bar.tooltip=If progress bar should step in texture pixels or screen pixels.\n(Screen pixels are way smaller and therefore smoother)
+modularui2.config.tooltip_pos=Tooltip Position
+modularui2.config.tooltip_pos.tooltip=Default tooltip position around the widget or its panel.
+modularui2.config.esc_restore_last_text=ESC Restores Last Text
+modularui2.config.esc_restore_last_text.tooltip=If true, pressing ESC key in the text field will restore the last text instead of confirming current one.
+modularui2.config.show_slot_overlay=Show Slot Overlay
+modularui2.config.show_slot_overlay.tooltip=If true, display the slot overlay when the slot is occupied.
+modularui2.config.gui_debug_mode=GUI Debug Mode
+modularui2.config.gui_debug_mode.tooltip=If true, widget outlines and widget information will be drawn.
+modularui2.config.use_dark_theme_by_default=Use Dark Theme By Default
+modularui2.config.use_dark_theme_by_default.tooltip=If true and not specified otherwise, screens will try to use the 'vanilla_dark' theme.
+modularui2.config.debug_text_color=Debug Text Color
+modularui2.config.debug_text_color.tooltip=Debug text color. Prefix Hex values with a #. Common colors can be referred by their name.
+modularui2.config.debug_outline_color=Debug Outline Color
+modularui2.config.debug_outline_color.tooltip=Debug outline color. Prefix Hex values with a #. Common colors can be referred by their name.
+modularui2.config.enable_test_guis=Enable Test GUIs
+modularui2.config.enable_test_guis.tooltip=Enables a test block, test item with a test gui and opening a gui by right clicking a diamond.
+modularui2.config.enable_test_overlays=Enable Test Overlays
+modularui2.config.enable_test_overlays.tooltip=Enables a test overlay shown on title screen and watermark shown on every GuiContainer.
+# modularui2.config.use_rich_tooltips=Enable RichTooltip
+# modularui2.config.use_rich_tooltips.tooltip=If true, vanilla tooltip will be replaced with MUI's RichTooltip