I hope you are patient. It looks like your issue will be a learning process for me, too, because when I attempt to open your code in a working page in my browser, I do not see anything like your screenshot in Firefox or Chrome.
The code that you posted looks like it is from your original code that might reside on a server because of what appears to be ASP.NET @calls. Browsers cannot interpret those calls so they display them as text. This is what I see:
If you can post a link to a web page, we can work with that.
If not, then set up the screenshot that you posted earlier and copy and post the HTML code that renders that screenshot by right-clicking the image in your browser window and selecting “View Page Source” or something like that, depends on your browser. That will display the code that the browser is rendering. We also need to be able to find the CSS that is styling the HTML, so the paths to resources need to be full URLs, not local paths, or you need to be sure to include all of the required resources in your post.
The key is simple, if you can click on the code on your computer (not the server or WAMP) and open it in your browser, then it will open in our browsers and we can troubleshoot the code.
Help us help you by giving us code that a browser can open straightaway.
I"m not so sure that this URL is valid
<link href="\stylesheet.css". The leading slash looks backwards. Maybe ASP reads it otherwise? What matters is that the browser sees it in a format that it can interpret.
Also, the ID #menubuttons has been used more than once on the page. IDs can be used only once on a page. Change menubuttons to a classname and it should work unless there is a problem with JS or specificity.
Use the HTML validator frequently. I never leave home wihout it. 