src/app.css

/* src/app.css */
:root {
  --primary: #3b82f6;
  --success: #10b981;
  --danger: #ef4444;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background-color: var(--gray-50);
  color: var(--gray-900);
  line-height: 1.5;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 1rem;
}

header {
  margin-bottom: 2rem;
}

h1 {
  margin: 0;
  font-size: 2rem;
  font-weight: 700;
  color: var(--gray-900);
}

.subtitle {
  margin: 0.25rem 0 0;
  color: var(--gray-600);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.loading, .error {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 400px;
  color: var(--gray-500);
}

.spinner {
  width: 40px;
  height: 40px;
  border: 4px solid var(--gray-200);
  border-top: 4px solid var(--primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.error {
  color: var(--danger);
}

.chart-section {
  background: white;
  border-radius: 0.5rem;
  padding: 1.5rem;
  box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
}

.chart-section h2 {
  margin: 0 0 1rem;
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--gray-900);
}

@media (max-width: 640px) {
  .container {
    padding: 1rem;
  }
  
  h1 {
    font-size: 1.5rem;
  }
  
  .grid {
    grid-template-columns: 1fr;
  }
}