JSFiddle - React, Tailwind, and code Playground

JavaScript

var css = "\
    #id1 {\
        border: 1px;\
        color: red;\
    }\
    #id2 {\
        border: 2px;\
        color: green;\
    }"; 
    

var array = css.replace(/[\t\n\r]*/g, '').replace(/\s{2}/g, ' ').split('}'),
    i = array.length-1,
    stack = [];

//close right brace
while(i--) {
    stack.unshift(array[i] + "}");
}

i =  stack.length;

var map = {};

while(i--) {
    map[stack[i].match(/(.*){.*}/)[1]] = stack[i].match(/.*{(.*)}/)[1];
}

for(i in map) {
    document.write('key: ' + i + ' | value: ' + map[i] + '<br />') 
}