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/@csstools/postcss-is-pseudo-class/dist/index.d.ts

@@ -0,0 +1,9 @@
+import type { PluginCreator } from 'postcss';
+declare type pluginOptions = {
+    preserve?: boolean;
+    onComplexSelector?: 'warning';
+    onPseudoElement?: 'warning';
+    specificityMatchingName?: string;
+};
+declare const creator: PluginCreator<pluginOptions>;
+export default creator;

node_modules/@csstools/postcss-is-pseudo-class/dist/split-selectors/complex.d.ts

@@ -0,0 +1,3 @@
+export default function complexSelectors(selectors: string[], pluginOptions: {
+    onComplexSelector?: 'warning';
+}, warnOnComplexSelector: () => void, warnOnPseudoElements: () => void): string[];

node_modules/@csstools/postcss-is-pseudo-class/dist/split-selectors/complex/child-adjacent-child.d.ts

@@ -0,0 +1 @@
+export declare function childAdjacentChild(selector: any): boolean;

node_modules/@csstools/postcss-is-pseudo-class/dist/split-selectors/complex/is-in-compound.d.ts

@@ -0,0 +1 @@
+export declare function isInCompoundWithOneOtherElement(selector: any): boolean;

node_modules/@csstools/postcss-is-pseudo-class/dist/split-selectors/compound-selector-order.d.ts

@@ -0,0 +1 @@
+export declare function sortCompoundSelectorsInsideComplexSelector(node: any): void;

node_modules/@csstools/postcss-is-pseudo-class/dist/split-selectors/split-selectors.d.ts

@@ -0,0 +1,3 @@
+export default function splitSelectors(selectors: string[], pluginOptions: {
+    specificityMatchingName: string;
+}, recursionDepth?: number): any[];