Here is how I do custom CSS for Internet Explorer:
In my JavaScript file:
function isIE () {
var myNav = navigator.userAgent.toLowerCase();
return (myNav.indexOf('msie') != -1) ? parseInt(myNav.split('msie')[1]) : false;
}
jQuery(document).ready(function(){
if(var_isIE){
if(var_isIE == 10){
jQuery("html").addClass("ie10");
}
if(var_isIE == 8){
jQuery("html").addClass("ie8");
// you can also call here some function to disable things that
//are not supported in IE, or override browser default styles.
}
}
});
And then in my CSS file, y define each different style:
.ie10 .some-class span{
.......
}
.ie8 .some-class span{
.......
}