Website layout gets messed up on resize

Hello good people of Stack Overflow, I am having great troubles with designing a website. I have pretty much finished the first page except for a bit of content, but that's not the question. I am using a PHP include to include a menu on top of each page, to keep it uniform. However, when I resize the window, in any browser, the links will begin wrapping. I think it is an issue with my CSS, or it could be a problem caused by my lack of PHP knowledge.

The link to my website is, builtbyhabel.net63.net. The code should be able to be seen on the developer tools for which开发者_StackOverflow中文版ever browser you are using.

Sounds like you have your links inside a container without a fixed width.

<div><a><a><a></div> <-- this one will contract with the width of your browser

vs

<div><a><a><a></div> <-- CSS div { width:978px; }