feat: update dependencies and add new styles

- Added node and sass to dependencies in package.json
- Added @types/node to devDependencies
- Removed unused CSS files and replaced them with SCSS files
- Updated import paths in App.tsx and Blog.tsx to use new aliasing
- Configured TypeScript paths for easier imports
- Updated Vite config to include path aliases
- Created new SCSS files for About, Blog, Error, and Main styles
- Added a variables file for color and effect variables
- Updated index.scss for global styles and responsive adjustments

vite.config.ts

@@ -1,7 +1,24 @@
 import { defineConfig } from 'vite'
 import react from '@vitejs/plugin-react'
+import path from 'path'
 
 // https://vite.dev/config/
 export default defineConfig({
-  plugins: [react()],
+  resolve: {
+    alias: {
+      "@":            path.resolve(__dirname, "/src"),
+      '@assets':      path.resolve(__dirname, 'src/assets'),
+      '@components':  path.resolve(__dirname, 'src/components'),
+      '@pages':       path.resolve(__dirname, 'src/pages'),
+      '@data':        path.resolve(__dirname, 'src/data'),
+      '@styles':      path.resolve(__dirname, 'src/assets/styles'),
+      '@public':      path.resolve(__dirname, 'src/public'),
+      '@tests':       path.resolve(__dirname, 'src/tests'),
+    }
+  },
+
+  plugins: [
+    react(),
+  ],
+  
 })