To include specific CSS files based on the browser type, conditional comments can be used:
<p class="accent">
<!--[if IE]>
This content is displayed for Internet Explorer<br />
<![endif]-->
<!--[if IE 6]>
This content is displayed for Internet Explorer 6<br />
<![endif]-->
<!--[if IE 7]>
This content is displayed for Internet Explorer 7<br />
<![endif]-->
<!--[if IE 8]>
This content is displayed for Internet Explorer 8<br />
<![endif]-->
<!--[if IE 9]>
This content is displayed for Internet Explorer 9<br />
<![endif]-->
<!--[if gte IE 8]>
This content is displayed for Internet Explorer 8 or higher<br />
<![endif]-->
<!--[if lt IE 9]>
This content is displayed for versions of Internet Explorer below 9<br />
<![endif]-->
<!--[if lte IE 7]>
This content is displayed for Internet Explorer 7 and lower<br />
<![endif]-->
<!--[if gt IE 6]>
This content is displayed for Internet Explorer greater than 6<br />
<![endif]-->
<!--[if !IE]> -->
This content is displayed for browsers other than Internet Explorer 5-9<br />
<!-- <![endif]-->
</p>
Furthermore, here's a JavaScript code snippet to identify the browser:
navigator.sayswho = (function () {
var N = navigator.appName,
ua = navigator.userAgent,
tem;
var M = ua.match(/(opera|chrome|safari|firefox|msie)\/?\s*(\.?\d+(\.\d+)*)/i);
if (M && (tem = ua.match(/version\/([\.\d]+)/i)) != null) M[2] = tem[1];
M = M ? [M[1], M[2]] : [N, navigator.appVersion, '-?'];
return M;
})();
For an example, check out this link: http://jsfiddle.net/42hmy/