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/stylehacks/src/plugins/starHtml.js

@@ -0,0 +1,50 @@
+'use strict';
+const parser = require('postcss-selector-parser');
+const exists = require('../exists');
+const isMixin = require('../isMixin');
+const BasePlugin = require('../plugin');
+const { IE_5_5, IE_6 } = require('../dictionary/browsers');
+const { SELECTOR } = require('../dictionary/identifiers');
+const { RULE } = require('../dictionary/postcss');
+const { HTML } = require('../dictionary/tags');
+
+module.exports = class StarHtml extends BasePlugin {
+  /** @param {import('postcss').Result=} result */
+  constructor(result) {
+    super([IE_5_5, IE_6], [RULE], result);
+  }
+
+  /**
+   * @param {import('postcss').Rule} rule
+   * @return {void}
+   */
+  detect(rule) {
+    if (isMixin(rule)) {
+      return;
+    }
+    parser(this.analyse(rule)).processSync(rule.selector);
+  }
+
+  /**
+   * @param {import('postcss').Rule} rule
+   * @return {parser.SyncProcessor<void>}
+   */
+  analyse(rule) {
+    return (selectors) => {
+      selectors.each((selector) => {
+        if (
+          exists(selector, 0, '*') &&
+          exists(selector, 1, ' ') &&
+          exists(selector, 2, HTML) &&
+          exists(selector, 3, ' ') &&
+          selector.at(4)
+        ) {
+          this.push(rule, {
+            identifier: SELECTOR,
+            hack: selector.toString(),
+          });
+        }
+      });
+    };
+  }
+};