Check out example codes for "see css from site". It will help you in understanding the concepts better.

Code Example 1

var sts = document.styleSheets;
var result = [];
for (var i = 0; i < sts.length; i++) {
    var st = sts.item(i);
    if (st && st.href) {
       result.push(st.href.match(/\w*\.css/));
    }
}
console.dir(result);

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