fix

js/interactive_grid.js

@@ -220,10 +220,10 @@ function drawBackgroundBefore() {
         const scaleX = canvasWidth / bgWidth;
         const scaleY = canvasHeight / bgHeight;
 
-        const scale = Math.max(scaleX, scaleY);
+        const scale = Math.min(scaleX, scaleY);
 
-        const newWidth = bgWidth * scaleX;
-        const newHeight = bgHeight * scaleX;
+        const newWidth = bgWidth * scale;
+        const newHeight = bgHeight * scale;
 
         const xOffset = (canvasWidth - newWidth) / 2;
         const yOffset = (canvasHeight - newHeight) / 2;
@@ -243,10 +243,10 @@ function drawBackgroundAfter() {
         const scaleX = canvasWidth / bgWidth;
         const scaleY = canvasHeight / bgHeight;
 
-        const scale = Math.max(scaleX, scaleY);
+        const scale = Math.min(scaleX, scaleY);
 
-        const newWidth = bgWidth * scaleX;
-        const newHeight = bgHeight * scaleX;
+        const newWidth = bgWidth * scale;
+        const newHeight = bgHeight * scale;
 
         const xOffset = (canvasWidth - newWidth) / 2;
         const yOffset = (canvasHeight - newHeight) / 2;