It's a bit more en vogue to handle mobile styling via media queries, which I generally agree is a better way to handle things (browser agnostic), but has the classic problem of a the browser needing to downloading resources it doesn't need (e.g. CSS for desktop version when on a mobile device).
You know what would be super radical? If we could do media queries within conditional comments.
<!-- [if (min-device-width: 481px)]>
That would combine the syntax and power of media queries, with the ability of conditional comments to load only the specific resources we need, staying streamlined in terms of bandwidth.
1 Notice in the first block of conditional comments above the slightly different syntax. The former is called a downlevel-hidden comment and the latter is a downlevel-revealed comment. Nerdgrammer.