feat: integrate Tailwind CSS and enhance MainForm component

- Added Tailwind CSS and related packages to the project.
- Refactored App.css and index.css to use Tailwind for styling.
- Enhanced MainForm component with improved form handling, validation, and layout using Material-UI and Tailwind CSS.
- Implemented dynamic error handling and submission feedback.
- Created a new Tailwind configuration file.

frontend/src/App.css

@@ -1,42 +1 @@
-#root {
-  max-width: 1280px;
-  margin: 0 auto;
-  padding: 2rem;
-  text-align: center;
-}
-
-.logo {
-  height: 6em;
-  padding: 1.5em;
-  will-change: filter;
-  transition: filter 300ms;
-}
-.logo:hover {
-  filter: drop-shadow(0 0 2em #646cffaa);
-}
-.logo.react:hover {
-  filter: drop-shadow(0 0 2em #61dafbaa);
-}
-
-@keyframes logo-spin {
-  from {
-    transform: rotate(0deg);
-  }
-  to {
-    transform: rotate(360deg);
-  }
-}
-
-@media (prefers-reduced-motion: no-preference) {
-  a:nth-of-type(2) .logo {
-    animation: logo-spin infinite 20s linear;
-  }
-}
-
-.card {
-  padding: 2em;
-}
-
-.read-the-docs {
-  color: #888;
-}
+@import "tailwindcss";