Product Landing Page ( error - solved )

When I scroll down with a mouse, 

YouTube video covers the Header.

I found error on " position: relativee; ".

I changed to " position: relative; ", 

but it's still unresolved.

So, I deleted it.

I deleted "position: relative;".

Also, I changed "width" and 

"height".

Now, It works well with the changed codes.

YouTube video does not cover the Header when scrolling down with a mouse.

making a "Product Landing Page" by "GitHub Codespaces" was more comfortable.

I always used Visual Studio Code.

I am currently making a "Product Landing Page".

For few days, I have used GitHub Codespaces. 

GitHub Codespaces has same functions like Visual Studio Code.

As a picture below,  we can create files and folders, and can check a result through Live Server as same as Visual Studio Code :

 

The most comfortable part was I could coding, update, and check the result right away on a same website.