As I can see in your CSS code you are selecting navigation with .nav which means select HTML element with class="nav" but you are having nav as a value of ID attribute and nav as HTML element, so either select it by nav which will target HTML tag or #nav which will target ID.
I thought marklenon95 did a good job in explaining the issue exactly. But I’ll try wording it differently.
The CSS has a selector that does not correspond to anything in the HTML.
Hence you need to either change the CSS selector so that it targets something in the HTML that does exist. Or change the HTML so that it matches the selector in the CSS
I typically write the HTML first and then write the CSS to go with it. And I typically try to avoid using id attributes as much as possible. But in this case, unless you want to rewrite the CSS, I would keep the CSS selector and replace the HTML id attribute with a class attribute unless the id is needed for some reason, in which case I’d add a class attribute.
@marklenon95 Ok now it sticks but now there are three problems problem 1. is that it’s spread out over 3 lines and doesn’t touch both sides 2. The logo disappears and finally the text on the howl page except the nav has changed from black to grey.