diff --git a/src/simulator/gui.odin b/src/simulator/gui.odin
index 9001087..4bcff9b 100644
--- a/src/simulator/gui.odin
+++ b/src/simulator/gui.odin
@@ -13,6 +13,15 @@ DISPLAY_PERCENT     :: 0.30
 CONTROL_BAR_H 		:: f32(50)
 STATUS_BAR_H  		:: f32(30)
 
+// ─── Layout constants ───────────────────────────────────────────────────
+PANEL_PADDING    :: 10
+PANEL_HEADER     :: 24
+BUTTON_HEIGHT    :: 30
+BUTTON_WIDTH     :: 120
+DROP_FONT_SIZE   :: 20
+KEYPAD_FONT_SIZE :: 18
+
+
 Layout :: struct {
 	control_bar : rl.Rectangle,
 	left_panel  : rl.Rectangle,