body {
      font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
      background: #f4f7fa;
      color: #333;
      margin: 0;
      padding: 40px 20px;
      display: flex;
      flex-direction: column;
      min-height: 100vh;
      align-items: center;
    }
    h1 {
      font-weight: 700;
      font-size: 2.5rem;
      margin-bottom: 10px;
      color: #2c3e50;
      text-align: center;
    }
    #json-input {
      width: 80vw;
      max-width: 700px;
      height: 250px;
      font-size: 1rem;
      font-family: monospace;
      padding: 10px;
      border: 1px solid #ccd6dd;
      border-radius: 6px;
      resize: vertical;
      box-shadow: inset 0 1px 3px #d1d9e6;
      margin-bottom: 16px;
      transition: border-color 0.3s ease;
    }
    #file-input-label {
      display: inline-block;
      background-color: #3498db;
      color: white;
      padding: 10px 20px;
      font-weight: 600;
      border-radius: 6px;
      cursor: pointer;
      margin-bottom: 16px;
      user-select: none;
    }
    #file-input {
      display: none;
    }
    #render-btn {
      background-color: #3498db;
      border: none;
      color: white;
      padding: 12px 24px;
      font-size: 1rem;
      font-weight: 600;
      border-radius: 6px;
      cursor: pointer;
      transition: background-color 0.3s ease;
      margin-bottom: 30px;
    }
    #render-btn:hover {
      background-color: #2980b9;
    }
    #lottie-container {
      width: 500px;
      height: 500px;
      border: 2px solid #3498db;
      border-radius: 10px;
      background: white;
      box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    }
    footer {
      margin-top: auto;
      font-size: 0.9rem;
      color: #666;
      padding: 20px;
      width: 100%;
      max-width: 700px;
      text-align: center;
      border-top: 1px solid #e1e4e8;
    }
    footer a {
      color: #3498db;
      text-decoration: none;
      font-weight: 600;
    }
    footer a:hover {
      text-decoration: underline;
    }
    @media (max-width: 600px) {
      #lottie-container {
        width: 90vw;
        height: 90vw;
      }
      #json-input {
        width: 90vw;
      }
    }