Maybe touch works correctly

inc/js/zoom.js

@@ -25,11 +25,12 @@ function zoom(factor, imgName) {
         img.style.opacity = 0;
     });
 
-    img.addEventListener("mousemove", (e) => {
+    img.addEventListener("touchmove", (e) => {
+        e.preventDefault();
         moveBackground(getOffsetToMiddle(e));
     });
 
-    img.addEventListener("touchmove", (e) => {
+    img.addEventListener("mousemove", (e) => {
         moveBackground(getOffsetToMiddle(e));
     });