I've create my own jQuery plugin to solve it
(function ($) {
$.fn.smartcss= function(i) {
var sel1 = this.selector;
var css1 = i;
// TOMAR DEL TAG STYLE Y/O DEL ARCHIVO .CSS
var css3;
$.each(document.styleSheets, function(sheetIndex, sheet) {
$.each(sheet.cssRules || sheet.rules, function(ruleIndex, rule) {
var sel3 = rule.selectorText.toLowerCase().split(',');
$.each(sel3,function(ii,jj){
if(jj.trim() == sel1){
var css2 = rule.style.getPropertyValue(css1);
if(typeof(css2 != 'undefined') && (css2 != null)){
css3 = css2;
} //typeof
} // jj==sel1
}) //each
}); // each
}); // each
// TOMAR DEL ATRIBUTO STYLE
var m2 = $(sel1).prop('style').cssText.split(';')
$.each(m2,function(ii,jj){
var m22 = jj.split(':');
if(m22[0].trim() == css1){
css3 = m22[1].trim();
}
}) //each
// TOMAR DE JQUERY
if(typeof(css3) == 'undefined'){
css3 = $(sel1).css(css1);
}
return css3;
};
}(jQuery));
How to:
$(document).ready(function(){
var css = $('#somediv').smartcss('width');
console.log(css);
});