"added impress-enabled and impress-disabled CSS classes used in impress initialization"

css/impress-demo.css

@@ -490,6 +490,7 @@ body     { pointer-events: none; }
     margin-bottom: 10px;
 }
 
+.impress-disabled .step,
 .impress-not-supported .step {
     position: relative;
     opacity: 1;

js/impress.js

@@ -338,6 +338,9 @@
             root.addEventListener(transitionEnd, onTransitionEnd, false);
             canvas.addEventListener(transitionEnd, onTransitionEnd, false);
             
+            body.classList.remove("impress-disabled");
+            body.classList.add("impress-enabled");
+            
             // get and init steps
             steps = $$(".step", root);            
             steps.forEach( initStep );
@@ -494,6 +497,8 @@
             stepTo(getElementFromUrl() || steps[0]);
         }, false);
         
+        body.classList.add("impress-disabled");
+        
         return (roots[ "impress-root-" + rootId ] = {
             init: init,
             stepTo: stepTo,