After putting my stylesheet through the CSS validator at W3C, I encountered only one error which read "Parse Error Opacity=60". The issue seems to be in this specific part of the CSS code:
/*Navigation Link styling */
#Nav a:link, a:visited {
display: inline-block;
width: 150px;
height: 150px;
font-weight: bold;
color: #FFFFFF;
background-color: #99FFFF;
text-align: center;
padding:5px;
text-decoration:none;
text-transform:uppercase;
filter:alpha(opacity=60);
opacity:0.6;
It appears that the validator isn't happy with the "filter:alpha(opacity=60);" segment - Could this be due to it not being a standard function? And is it safe to ignore this particular error?
Cheers