     margin: 0 auto;
      background: white;
      border-radius: 16px;
      padding: 24px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    }

    h1 {
      text-align: center;
      color: #333;
      margin-bottom: 24px;
      font-size: 24px;
      font-weight: 600;
    }

    #dropzone {
      width: 100%;
      min-height: 120px;
      border: 3px dashed #667eea;
      border-radius: 12px;
      text-align: center;
      padding: 24px;
      margin-bottom: 24px;
      background: linear-gradient(