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

tsconfig.json

@@ -3,5 +3,20 @@
   "references": [
     { "path": "./tsconfig.app.json" },
     { "path": "./tsconfig.node.json" }
-  ]
+  ],
+
+  "compilerOptions": {
+    "baseUrl": ".",
+    "paths": {
+      "@/*":            ["src/*"],
+      "@assets/*":      ["src/assets/*"],
+      "@components/*":  ["src/components/*"],
+      "@pages/*":       ["src/pages/*"],
+      "@data/*":        ["src/data/*"],
+      "@styles/*":      ["src/styles/*"],
+      "@tests/*":       ["src/tests/*"],
+    },
+    "moduleResolution": "node",
+    "types": ["node"] 
+  }
 }