The reason it's not working is because you're using the <center>
element. This element is obsolete. You should use CSS to determine its position (you could put text-align: center;
on .navigation
.) Don't use obsolete elements. Once you do that, the word-spacing
works fine.
http://validator.w3.org/ and http://jigsaw.w3.org/css-validator/ help to check your page for syntax errors humans can easily miss. They are an invaluable tool for people developing websites.