.App {
  text-align: center;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
    'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
    sans-serif;
  color: #333;
}

.App-header {
  background-color: #282c34;
  padding: 20px;
  color: white;
}

main {
  padding: 20px;
}

.controls {
  margin-bottom: 20px;
}

.controls label {
  margin-right: 10px;
  font-size: 1.1em;
}

.controls select {
  padding: 8px 12px;
  font-size: 1em;
  border-radius: 5px;
  border: 1px solid #ccc;
}

.chart-container {
  max-width: 1000px;
  margin: auto;
  padding: 20px;
  border-radius: 8px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.loading-indicator {
  padding: 50px;
  font-size: 1.5em;
  color: #555;
}

.spinner {
  margin: 20px auto;
  border: 8px solid #f3f3f3;
  border-top: 8px solid #3498db;
  border-radius: 50%;
  width: 60px;
  height: 60px;
  animation: spin 2s linear infinite;
}

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