HTML item rejected

Hello community, a couple of days ago we uploaded our first article to themeforest and it was rejected with the following message:

Unfortunately we found it isn’t at the quality standard required to move forward, and you won’t be able to re-submit this item again.

We have compared with articles already published and they are relatively simpler and are published without problem.

Even so, we would like to know what we failed in order to improve, our demo is: DEMO