How do I make a Transparent Header

Hi, I’m sorry for asking so many questions. I’ve tried this code and it does now work on ios also but I wanted to ask if there is a solution for this issue where the header covers stuff below it, i’ve attached a screenshot to show what i mean. The header goes a bit too low on both desktop and mobile, I understand if you are not able to help with this as you have already helped a lot! Thank you so much for everything anyways.