* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background: cornflowerblue;
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 20px;
        }

        .container {
            background: white;
            border-radius: 20px;
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
            padding: 40px;
            max-width: 600px;
            width: 100%;
            text-align: center;
        }

        .logo {
            width: 360px;
            height: auto;
            margin-bottom: 30px;
            max-width: 100%;
            height: auto;
        }

        h1 {
            color: #333;
            margin-bottom: 20px;
            font-size: 24px;
            font-weight: 600;
        }

        .description {
            color: #666;
            margin-bottom: 30px;
            line-height: 1.6;
            font-size: 16px;
        }

        .upload-area {
            border: 2px dashed #ddd;
            border-radius: 15px;
            padding: 40px 20px;
            margin-bottom: 30px;
            transition: all 0.3s ease;
            cursor: pointer;
        }

        .upload-area:hover {
            border-color: #667eea;
            background-color: #f8f9ff;
        }

        .upload-area.dragover {
            border-color: #667eea;
            background-color: #f0f4ff;
        }

        .upload-icon {
            font-size: 48px;
            color: #ddd;
            margin-bottom: 15px;
        }

        .file-input {
            display: none;
        }

        .upload-text {
            color: #666;
            margin-bottom: 10px;
        }

        .file-types {
            color: #999;
            font-size: 14px;
        }

        .selected-file {
            background: #f0f4ff;
            border-radius: 10px;
            padding: 15px;
            margin: 20px 0;
            display: none;
        }

        .submit-btn {
            background: linear-gradient(135deg, #4169e1 0%, #1e3a8a 100%);
            color: white;
            border: none;
            padding: 15px 40px;
            border-radius: 25px;
            font-size: 16px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            margin-bottom: 20px;
        }

        .submit-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 10px 20px rgba(102, 126, 234, 0.3);
        }

        .submit-btn:disabled {
            opacity: 0.6;
            cursor: not-allowed;
            transform: none;
        }

        .loading {
            display: none;
            margin: 20px 0;
        }

        .spinner {
            border: 3px solid #f3f3f3;
            border-top: 3px solid #667eea;
            border-radius: 50%;
            width: 30px;
            height: 30px;
            animation: spin 1s linear infinite;
            margin: 0 auto 10px;
        }

        @keyframes spin {
            0% { transform: rotate(0deg); }
            100% { transform: rotate(360deg); }
        }

        .result {
            display: none;
            margin-top: 30px;
        }

        .download-btn {
            background: #28a745;
            color: white;
            border: none;
            padding: 12px 30px;
            border-radius: 20px;
            font-size: 14px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            margin-top: 15px;
        }

        .download-btn:hover {
            background: #218838;
            transform: translateY(-1px);
        }

        .error {
            color: #dc3545;
            background: #f8d7da;
            border: 1px solid #f5c6cb;
            border-radius: 10px;
            padding: 15px;
            margin: 20px 0;
            display: none;
        }

        .success {
            color: #155724;
            background: #d4edda;
            border: 1px solid #c3e6cb;
            border-radius: 10px;
            padding: 15px;
            margin: 20px 0;
            display: none;
        }