/* Playful visual style */
    body {
      font-family: 'Comic Sans MS', sans-serif;
      background: #fef6e4;
      color: #333;
      margin: 0;
      padding: 0;
    }

    header {
      background-color: #ffcb77;
      padding: 2rem;
      text-align: center;
      color: #3b3b58;
    }

    header h1 {
      margin: 0;
      font-size: 2.5rem;
    }

    header p {
      margin-top: 0.5rem;
      font-size: 1.2rem;
    }

    main {
      padding: 2rem;
      max-width: 900px;
      margin: auto;
    }

    section {
      background-color: #ffe8d6;
      padding: 1.5rem;
      margin-bottom: 2rem;
      border-radius: 15px;
      box-shadow: 3px 3px 10px rgba(0,0,0,0.1);
    }

    section h2 {
      color: #3b3b58;
    }

    .colab-button, .home-button {
      display: inline-block;
      background-color: #ff6b6b;
      color: white;
      padding: 0.5rem 1rem;
      border-radius: 8px;
      text-decoration: none;
      margin: 0.5rem 0;
      font-weight: bold;
    }

    .colab-button:hover, .home-button:hover {
      background-color: #ff4b4b;
    }

    footer {
      text-align: center;
      padding: 1rem;
      background-color: #ffcb77;
      color: #3b3b58;
      margin-top: 2rem;
    }

    pre {
      background-color: #fff2e6;
      padding: 1rem;
      border-radius: 8px;
      overflow-x: auto;
    }

    .exercise {
      background-color: #ffd8c4;
      padding: 1rem;
      border-radius: 8px;
      margin-top: 1rem;
    }