Initial commit: Developer Tools MVP with visual editor

- Complete React app with 7 developer tools
- JSON Tool with visual structured editor
- Serialize Tool with visual structured editor
- URL, Base64, CSV/JSON, Beautifier, Diff tools
- Responsive navigation with dropdown menu
- Dark/light mode toggle
- Mobile-responsive design with sticky header
- All tools working with copy/paste functionality

node_modules/clean-css/lib/optimizer/level-2/properties/has-same-values.js

@@ -0,0 +1,14 @@
+function hasSameValues(property) {
+  var firstValue = property.value[0][1];
+  var i, l;
+
+  for (i = 1, l = property.value.length; i < l; i++) {
+    if (property.value[i][1] != firstValue) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+module.exports = hasSameValues;