Alright, a few questions..
1) Printscreen please
2) What browser are you using precisely (version)
3) Did you save your file as mypage.html or mypage.html.txt (to see the file's full name, go to 'My Computer' -> 'Tools' -> 'Folder Options' -> 'View' -> uncheck 'Hide extensions for known file types', click 'Ok', then go to the directory where your .html file is and see if it's .html or .html.txt)
4) CSS syntax is like this:
ElementName
{
attributeName: value;
}
Not really hard to understand. A semicolon is used in most languages as a seperator, a sort of 'Enter'.
That's all. Try to use this style, it's more readable.
5) Is it a white stone wall?
6) Is your stone wall actually displayed on the page?
5 & 6 need a printscreen. lol
And this code is what shows up on my page as text and not as HTML and not hidden.
Your whole code or just that CSS line?
Please answer all the questions so we can further help you better.
Big