MAGETWO-44261: fixed style on mobile version

Author: dazvolt

app/design/frontend/Magento/blank/Magento_ProductVideo/web/css/source/_module.less

@@ -63,6 +63,16 @@
     }
 }
 
+@media only screen
+and (min-device-width : 320px)
+and (max-device-width : 780px)
+and (orientation : landscape) {
+    .product-video {
+        height: 100%;
+        width: 81%;
+    }
+}
+
 .fotorama__arr.hidden-video {
     z-index: -1;
 }