diff --git a/main.c b/main.c
index 74d2467..ad0e07f 100644
--- a/main.c
+++ b/main.c
@@ -377,20 +377,24 @@ void DrawControlPanel(Michelson *mic) {
     int rows = (mic->lambdasCount + cols - 1) / cols;
     startY += (rows * (btnH + 5)) + 20;
 
-
-    // Pos M1
+    // Pos M1 M2 (d1 - d2)
     startY += 0;
-    DrawText(TextFormat("Position M1 : %.2f um", mic->d1), startX, startY, 20, ORANGE);
+    float currentDiff = mic->d1 - mic->d2;
+    DrawText(TextFormat("Distance M1 - M2: %.2f um", currentDiff), startX, startY, 20, ORANGE);
    
     // Pas des + et -
     float stepD1 = speedMode ? 0.05f : 0.006f;
 
     if (GuiButtonRepeat((Rectangle){startX, startY + 30, btnSize, 25}, "-", shouldRepeat)) mic->d1 -= stepD1;
-    GuiSlider((Rectangle){startX + btnSize + 5, startY + 30, sliderWidth - 75, 25}, NULL, NULL, &mic->d1, 100, 600);
+
+    float sliderVal = currentDiff;
+    GuiSlider((Rectangle){startX + btnSize + 5, startY + 30, sliderWidth - 75, 25}, NULL, NULL, &sliderVal, -100.0f, 100.0f);
+    mic->d1 = mic->d2 + sliderVal;
+
+    if (GuiButtonRepeat((Rectangle){startX, startY + 30, btnSize, 25}, "-", shouldRepeat)) mic->d1 -= stepD1;
     if (GuiButtonRepeat((Rectangle){startX + btnSize + sliderWidth - 65, startY + 30, btnSize, 25}, "+", shouldRepeat)) mic->d1 += stepD1;
     if (GuiButton((Rectangle){startX + contentWidth - 60, startY + 30, 60, 25}, "Egal")) mic->d1 = mic->d2;
 
-
     // Angle M1 X
     startY += 90;
     DrawText(TextFormat("Inclinaison M1: %.3f deg", mic->angleM1), startX, startY, 20, ORANGE);
@@ -571,7 +575,7 @@ int main () {
     #endif
 
     mic.center = (Vector2){ UI_WIDTH + (1920 - UI_WIDTH) / 2.0f - 100, 1080 / 2.0f };
-    mic.d1 = 300.0f;
+    mic.d1 = 265.0f;
     mic.d2 = 250.0f;
     mic.lambdas[0] = 550.0f;
     mic.lambdasCount = 1;