I'm having trouble changing the fill color of an SVG when the user hovers over it. Can someone help me figure out why my code isn't working?
svg:hover {
fill: blue;
}
<svg width="0" height="0" class="hidden">
<symbol viewBox="0 0 142 142" xmlns="http://www.w3.org/2000/svg" id="twitter">
<title>twitter</title>
<g fill="none" fill-rule="evenodd">
<path d="M71.5 0C115.23 0 142 36.15 142 71.217c0 35.066-26.77 69.484-70.5 70.783C27.77 143.299 0 106.629 0 71S27.77 0 71.5 0z" fill="#AEB2B4"></path>
<path d="M109 47.34a31.017 31.017 0 0 1-8.956 2.462 15.689 15.689 0 0 0 6.857-8.658A31.142 31.142 0 0 1 97 44.94 15.55 15.55 0 0 0 85.616 40c-8.61 0-15.593 7.01-15.593 15.652 0 1.227.139 2.421.406 3.567-12.958-.652-24.448-6.883-32.14-16.356a15.63 15.63 0 0 0-2.111 7.87 15.667 15.667 0 0 0 6.936 13.028 15.437 15.437 0 0 1-7.062-1.96V62c0 7.584 5.376 13.909 12.508 15.346-1.307.36-2.688.55-4.107.55-1.007 0-1.983-.097-2.934-.28 1.984 6.218 7.74 10.743 14.565 10.87a31.209 31.209 0 0 1-19.366 6.7c-1.256 0-2.5-.073-3.718-.219A43.983 43.983 0 0 0 56.9 102c28.68 0 44.364-23.85 44.364-44.535 0-.678-.015-1.354-.046-2.024A31.687 31.687 0 0 0 109 47.34z"
fill="#FFF" fill-rule="nonzero"></path>
</g>
</symbol>
</svg>
<svg class="icon">
<use xlink:href="#twitter"></use>
</svg>