Mobile js fix for height of zoom bg

inc/js/zoom.js

@@ -4,7 +4,7 @@
  * images inside their box without touching the rest of the layout.
  * Author: phga/teord
  * Date: 2019-10-20
- * Version: 1.1
+ * Version: 1.2
  */
 function zoom(factor, imgName) {
     let img = document.getElementById(imgName);
@@ -15,6 +15,11 @@ function zoom(factor, imgName) {
     // Fix for firefox, somehow width larger than content (inline-block)
     magni.style.width = "100%";
     magni.style.width = img.width;
+    // mobile fix (for some browsers)
+    if (Math.max(document.documentElement.clientWidth, window.innerWidth) < 800) {
+        magni.style.height = "50%";
+        magni.style.height = img.height;
+    }
     // setup the padding (bigger zoom canvas)
     magni.style.padding = offset.y + "px " + offset.x + "px";
     // adjust the margin to ged rid of the extra size gained from padding