Initial commit: PriceGhost price tracking application

Full-stack application for tracking product prices:
- Backend: Node.js + Express + TypeScript
- Frontend: React + Vite + TypeScript
- Database: PostgreSQL
- Price scraping with Cheerio
- JWT authentication
- Background price checking with node-cron
- Price history charts with Recharts
- Docker support with docker-compose

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/src/index.css

@@ -0,0 +1,225 @@
+* {
+  margin: 0;
+  padding: 0;
+  box-sizing: border-box;
+}
+
+:root {
+  --primary: #6366f1;
+  --primary-dark: #4f46e5;
+  --secondary: #10b981;
+  --danger: #ef4444;
+  --background: #f8fafc;
+  --surface: #ffffff;
+  --text: #1e293b;
+  --text-muted: #64748b;
+  --border: #e2e8f0;
+  --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
+  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
+}
+
+body {
+  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen,
+    Ubuntu, Cantarell, sans-serif;
+  background-color: var(--background);
+  color: var(--text);
+  line-height: 1.6;
+}
+
+a {
+  color: var(--primary);
+  text-decoration: none;
+}
+
+a:hover {
+  text-decoration: underline;
+}
+
+button {
+  cursor: pointer;
+  font-family: inherit;
+}
+
+input, button {
+  font-size: 1rem;
+}
+
+.container {
+  max-width: 1200px;
+  margin: 0 auto;
+  padding: 0 1rem;
+}
+
+/* Form styles */
+.form-group {
+  margin-bottom: 1rem;
+}
+
+.form-group label {
+  display: block;
+  margin-bottom: 0.5rem;
+  font-weight: 500;
+  color: var(--text);
+}
+
+.form-group input,
+.form-group select {
+  width: 100%;
+  padding: 0.75rem;
+  border: 1px solid var(--border);
+  border-radius: 0.5rem;
+  font-size: 1rem;
+  transition: border-color 0.2s, box-shadow 0.2s;
+}
+
+.form-group input:focus,
+.form-group select:focus {
+  outline: none;
+  border-color: var(--primary);
+  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
+}
+
+/* Button styles */
+.btn {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  padding: 0.75rem 1.5rem;
+  border: none;
+  border-radius: 0.5rem;
+  font-weight: 500;
+  transition: all 0.2s;
+}
+
+.btn-primary {
+  background-color: var(--primary);
+  color: white;
+}
+
+.btn-primary:hover {
+  background-color: var(--primary-dark);
+}
+
+.btn-secondary {
+  background-color: var(--surface);
+  color: var(--text);
+  border: 1px solid var(--border);
+}
+
+.btn-secondary:hover {
+  background-color: var(--background);
+}
+
+.btn-danger {
+  background-color: var(--danger);
+  color: white;
+}
+
+.btn-danger:hover {
+  background-color: #dc2626;
+}
+
+.btn:disabled {
+  opacity: 0.6;
+  cursor: not-allowed;
+}
+
+/* Card styles */
+.card {
+  background: var(--surface);
+  border-radius: 0.75rem;
+  box-shadow: var(--shadow);
+  overflow: hidden;
+}
+
+.card-header {
+  padding: 1rem 1.5rem;
+  border-bottom: 1px solid var(--border);
+}
+
+.card-body {
+  padding: 1.5rem;
+}
+
+/* Alert styles */
+.alert {
+  padding: 1rem;
+  border-radius: 0.5rem;
+  margin-bottom: 1rem;
+}
+
+.alert-error {
+  background-color: #fef2f2;
+  color: #991b1b;
+  border: 1px solid #fecaca;
+}
+
+.alert-success {
+  background-color: #f0fdf4;
+  color: #166534;
+  border: 1px solid #bbf7d0;
+}
+
+/* Loading spinner */
+.spinner {
+  display: inline-block;
+  width: 1.5rem;
+  height: 1.5rem;
+  border: 2px solid var(--border);
+  border-top-color: var(--primary);
+  border-radius: 50%;
+  animation: spin 0.8s linear infinite;
+}
+
+@keyframes spin {
+  to {
+    transform: rotate(360deg);
+  }
+}
+
+/* Utility classes */
+.text-center {
+  text-align: center;
+}
+
+.text-muted {
+  color: var(--text-muted);
+}
+
+.mt-1 { margin-top: 0.25rem; }
+.mt-2 { margin-top: 0.5rem; }
+.mt-3 { margin-top: 1rem; }
+.mt-4 { margin-top: 1.5rem; }
+
+.mb-1 { margin-bottom: 0.25rem; }
+.mb-2 { margin-bottom: 0.5rem; }
+.mb-3 { margin-bottom: 1rem; }
+.mb-4 { margin-bottom: 1.5rem; }
+
+.flex {
+  display: flex;
+}
+
+.flex-col {
+  flex-direction: column;
+}
+
+.items-center {
+  align-items: center;
+}
+
+.justify-between {
+  justify-content: space-between;
+}
+
+.gap-2 {
+  gap: 0.5rem;
+}
+
+.gap-3 {
+  gap: 1rem;
+}
+
+.gap-4 {
+  gap: 1.5rem;
+}