Update index.js

aspect ratio match the one of the code bloc

index.js

@@ -24,11 +24,12 @@
   var gifUrl = getScriptQueryParam("gif_url");
   var plyUrl = getScriptQueryParam("ply_url");
 
-  // Read the aspect ratio input.
-  // The expected format is either "width:height" (e.g., "16:9") or a decimal representing width/height.
+  // Determine the aspect ratio.
+  // Default aspect: 1:1 (i.e. 100% padding-bottom)
+  var aspectPercent = "100%";
   var aspectParam = getScriptQueryParam("aspect");
-  var aspectPercent = "100%"; // default: 1:1 aspect ratio
   if (aspectParam) {
+    // Expected format: "width:height" (e.g. "16:9") or a decimal number.
     if (aspectParam.indexOf(":") !== -1) {
       var parts = aspectParam.split(":");
       var w = parseFloat(parts[0]);
@@ -42,6 +43,14 @@
         aspectPercent = (100 / aspectValue) + "%";
       }
     }
+  } else {
+    // If no aspect parameter is provided, compute the aspect ratio from the parent element.
+    var parentContainer = document.currentScript.parentNode;
+    var containerWidth = parentContainer.offsetWidth;
+    var containerHeight = parentContainer.offsetHeight;
+    if (containerWidth > 0 && containerHeight > 0) {
+      aspectPercent = (containerHeight / containerWidth * 100) + "%";
+    }
   }
 
   // Optional parameters for zoom and rotation limits.