It doesn't work because its having issues with your :focus
pseudo selector which is applied to your <a>
.
First you need to understand that you are only supporting gecko based browsers (Mozilla Firefox) by adding the vendor prefix of -moz to your CSS.
There's a website that helps you make gradients so you can copy and paste them and they have an image as a fallback so it looks good in older browsers too.
So it will end up looking like this:
#access li a:hover,
#access li a:focus {
background: #f99733;
background: url(data:image/svg+xml;base64,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);
background: -moz-radial-gradient(center, ellipse cover, #f99733 0%, #e47300 100%);
background: -webkit-gradient(radial, center center, 0px, center center, 100%, color-stop(0%,#f99733), color-stop(100%,#e47300));
background: -webkit-radial-gradient(center, ellipse cover, #f99733 0%,#e47300 100%);
background: -o-radial-gradient(center, ellipse cover, #f99733 0%,#e47300 100%);
background: -ms-radial-gradient(center, ellipse cover, #f99733 0%,#e47300 100%);
background: radial-gradient(ellipse at center, #f99733 0%,#e47300 100%);
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#f99733', endColorstr='#e47300',GradientType=1 );
}
I find that this works for me in most cases and its based on what I understand your specific needs are.