 <p>From my experimenting, I've found that Safari 5 (for desktop and iOS) will most certainly render your page in the way you intend using either one of your solutions. Firefox 9, on the other hand, does not appear to respect @-moz-keyframe or -moz-animation rules if they are placed in @media blocks (and both ignore the W3C @keyframe and non-vendor specific animation properties)</p>