diff --git a/gui/index.html b/gui/index.html
index 55ce775..cb3d119 100644
--- a/gui/index.html
+++ b/gui/index.html
@@ -149,9 +149,9 @@
                 <line x1="-17" y1="22"  x2="17" y2="22"  stroke="rgba(0,255,145,.58)" stroke-width=".9"/>
                 <line x1="-10" y1="-11" x2="10" y2="-11" stroke="rgba(0,255,145,.42)" stroke-width=".85"/>
                 <line x1="-10" y1="11"  x2="10" y2="11"  stroke="rgba(0,255,145,.42)" stroke-width=".85"/>
-                <line id="imu-horizon-main" x1="-40" y1="0" x2="40" y2="0" stroke="rgba(0,255,145,.95)" stroke-width="2.8"/>
-                <line x1="-40" y1="0" x2="-32" y2="-5" stroke="rgba(0,255,145,.95)" stroke-width="2.8"/>
-                <line x1="40"  y1="0" x2="32"  y2="-5" stroke="rgba(0,255,145,.95)" stroke-width="2.8"/>
+                <line id="imu-horizon-main" x1="-60" y1="0" x2="60" y2="0" stroke="rgba(0,255,145,.95)" stroke-width="2.8"/>
+                <line x1="-60" y1="0" x2="-52" y2="-5" stroke="rgba(0,255,145,.95)" stroke-width="2.8"/>
+                <line x1="60"  y1="0" x2="52"  y2="-5" stroke="rgba(0,255,145,.95)" stroke-width="2.8"/>
               </g>
               <!-- HDG readout with background box (wider for compass direction) -->
               <rect x="-42" y="-72" width="84" height="15" fill="rgba(0,15,8,.65)" rx="1"/>
@@ -1162,9 +1162,9 @@ function drawImuHorizonOverlay(context, canvasWidth, canvasHeight, size) {
 
   context.strokeStyle = "rgba(0,255,145,.95)";
   context.lineWidth = 2.8 * unit;
-  context.beginPath(); context.moveTo(-40 * unit, 0); context.lineTo(40 * unit, 0); context.stroke();
-  context.beginPath(); context.moveTo(-40 * unit, 0); context.lineTo(-32 * unit, -5 * unit); context.stroke();
-  context.beginPath(); context.moveTo(40 * unit, 0); context.lineTo(32 * unit, -5 * unit); context.stroke();
+  context.beginPath(); context.moveTo(-60 * unit, 0); context.lineTo(60 * unit, 0); context.stroke();
+  context.beginPath(); context.moveTo(-60 * unit, 0); context.lineTo(-52 * unit, -5 * unit); context.stroke();
+  context.beginPath(); context.moveTo(60 * unit, 0); context.lineTo(52 * unit, -5 * unit); context.stroke();
   context.restore();
 
   /* HDG box + text labels */