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/postcss-nesting/dist/lib/merge-selectors/combinations-of-size-n.d.ts

@@ -0,0 +1 @@
+export declare function combinationsWithSizeN(set: Array<string>, n: number): Array<Array<string>>;

node_modules/postcss-nesting/dist/lib/merge-selectors/compound-selector-order.d.ts

@@ -0,0 +1,2 @@
+import type { Container, Node } from 'postcss-selector-parser';
+export declare function sortCompoundSelectorsInsideComplexSelector(node: Container<string, Node>): void;

node_modules/postcss-nesting/dist/lib/merge-selectors/merge-selectors.d.ts

@@ -0,0 +1,2 @@
+import { options } from '../options';
+export default function mergeSelectors(fromSelectors: Array<string>, toSelectors: Array<string>, opts: options): any[];

node_modules/postcss-nesting/dist/lib/merge-selectors/specificity.d.ts

@@ -0,0 +1 @@
+export declare function nodesAreEquallySpecific(nodes: Array<string>): boolean;