* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
    'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
    sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.app {
  min-height: 100vh;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  padding: 2rem;
}

.back-button {
  margin-bottom: 1rem;
  background: white;
  color: #667eea;
  border: 2px solid #667eea;
}

.back-button:hover {
  background: #667eea;
  color: white;
}