Fix getStyleValue function

src/core.js

@@ -88,7 +88,7 @@ function getStyleValue($$, selector, property) {
     if(isNode()){
         if(!nodeCss){
             var style = require('fs').readFileSync(__filename.replace('c3.js', 'c3.css'), 'utf-8');
-            nodeCss = [require('css').parse(style), require('css').parse($$.ed3Config.style)];
+            nodeCss = [require('css').parse($$.ed3Config.style), require('css').parse(style)];
         }
 
         var obj, rule, sel, decl;
@@ -100,6 +100,7 @@ function getStyleValue($$, selector, property) {
                 if(!rule.selectors) continue;
                 for(var k = 0; k<rule.selectors.length; k++){
                     sel = rule.selectors[k];
+                    if(sel !== selector) continue;
                     for(var l = 0; l<rule.declarations.length; l++){
                         decl = rule.declarations[l];
                         if(decl.property === property){
@@ -135,6 +136,8 @@ function getStyleValue($$, selector, property) {
     }
 }
 
+c3.getStyleValue = getStyleValue;
+
 
 c3_chart_internal_fn.init = function () {
     var $$ = this, config = $$.config;