body {
    font-family: Arial, sans-serif;
    background: #f5f5f5;
    color: #333;
    padding: 20px;
    text-align: center;
  }
  
  h1 {
    font-size: 2rem;
    margin-bottom: 20px;
  }
  
  .metrics {
    display: flex;
    justify-content: center;
    gap: 30px;
    flex-wrap: wrap;
    margin-bottom: 20px;
  }
  
  .metrics div {
    background: #ffffff;
    padding: 15px 20px;
    border-radius: 10px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    font-size: 1.1rem;
    min-width: 180px;
  }
  
  canvas {
    max-width: 100%;
    margin: auto;
  }
  
  .alert {
    background: #ffe0e0;
    border: 1px solid #ff3333;
    padding: 15px;
    margin: 20px auto;
    font-weight: bold;
    color: #900;
    border-radius: 8px;
    box-shadow: 0 0 10px #ffaaaa;
    max-width: 600px;
  }
  
  .hidden {
    display: none;
  }