Why does this question get a downvote? And how can I improve it?

I sometimes have a hard time asking questions on Stack Overflow. I did read the how to ask tutorial multiple times.

However, when I ask a question, I get a downvote without explanation. I don't really care about the downvote or reputation lost, but knowing why my question was downvoted would be really helpful for future questions.

Also, I'm scared of facing the "We are no longer accepting questions/answers from this account" message again. I saw this when I was new to the site and had two questions with a score of −2 (and some without a vote).

I improved my questions after that and wasn't getting downvotes on them any more, but now, almost immediately after I ask a question, I get a downvote. I have waited for details on how to improve it, but no comment ever came.

So I was comparing my most recent question to my previous upvoted questions, and I really don't understand why it was downvoted. I provided all the necessary content, I have a well-explained problem, I've shown what I've tried so far, I have a working "snippet", and I've explained what I can and cannot use.

The lack of an explanation brought me here. Can you guys help me improve my question?

UPDATE

After a lot of feedback, in the comments and answers, I've improved the question in question. And received a lot of positive feedback.

So the question is not as it was anymore. For simplicity, I copied the original question and pasted it here. Alot of people are reading this topic, and this might help them to improve their questions.

Keep footer at bottom when page height dynamically changes. Without flexbox or JavaScript
There are alot of topics out there, giving solutions to keep the footer at the bottom of a page. I am struggling however to get it working.
The problem is that the page can dynamically change its height.
With the current solution im using, found here, the footer is at the bottom of the page. But when the page height dynamically changes, thefooter remains at its exact position.
See snippet below for a visual demo (best used in full window mode)
Go for snippet to the original question. I can't get it working inside the quote :(
How can i let css know the height changed? And to keep that footer at the bottom of the document instead that its staying at the bottom of the window?
I cannot use flexbox or JavaScript.
- Source: Keep footer at bottom of page when page height dynamically changes using CSS