.pdf-merger-container {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        .pdf-merger-header {
            background-color: #e5332d;
            color: white;
            padding: 60px 0;
            text-align: center;
            margin-bottom: 50px;
        }
        
        .pdf-merger-header h1 {
            font-size: 2.5rem;
            font-weight: 600;
            margin-bottom: 15px;
        }
        
        .pdf-merger-header p {
            font-size: 1.1rem;
            opacity: 0.95;
        }
        
        .pdf-upload-area {
            border: 3px dashed #dee2e6;
            border-radius: 10px;
            padding: 60px 20px;
            text-align: center;
            background-color: #f8f9fa;
            cursor: pointer;
            transition: all 0.3s ease;
            margin-bottom: 30px;
        }
        
        .pdf-upload-area:hover {
            border-color: #e5332d;
            background-color: #fff;
        }
        
        .pdf-upload-area.dragover {
            border-color: #e5332d;
            background-color: #fff5f5;
        }
        
        .pdf-upload-icon {
            font-size: 4rem;
            color: #e5332d;
            margin-bottom: 20px;
        }
        
        .pdf-upload-btn {
            background-color: #e5332d;
            color: white;
            border: none;
            padding: 15px 40px;
            font-size: 1.1rem;
            border-radius: 5px;
            cursor: pointer;
            transition: all 0.3s ease;
        }
        
        .pdf-upload-btn:hover {
            background-color: #c72a24;
            transform: translateY(-2px);
            box-shadow: 0 4px 12px rgba(229, 51, 45, 0.3);
        }
        
        .pdf-file-list {
            margin-top: 30px;
        }
        
        .pdf-file-item {
            background: white;
            border: 1px solid #dee2e6;
            border-radius: 8px;
            padding: 20px;
            margin-bottom: 15px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            transition: all 0.3s ease;
            cursor: move;
        }
        
        .pdf-file-item:hover {
            box-shadow: 0 4px 12px rgba(0,0,0,0.1);
        }
        
        .pdf-file-item.dragging {
            opacity: 0.5;
            border: 2px dashed #e5332d;
        }
        
        .pdf-file-info {
            display: flex;
            align-items: center;
            flex: 1;
        }
        
        .pdf-file-icon {
            font-size: 2.5rem;
            color: #e5332d;
            margin-right: 20px;
        }
        
        .pdf-file-details h5 {
            margin: 0 0 5px 0;
            font-size: 1rem;
            font-weight: 600;
        }
        
        .pdf-file-details p {
            margin: 0;
            color: #6c757d;
            font-size: 0.9rem;
        }
        
        .pdf-file-actions {
            display: flex;
            gap: 10px;
        }
        
        .pdf-action-btn {
            background: none;
            border: none;
            font-size: 1.2rem;
            cursor: pointer;
            padding: 8px 12px;
            border-radius: 5px;
            transition: all 0.3s ease;
        }
        
        .pdf-drag-handle {
            color: #6c757d;
        }
        
        .pdf-drag-handle:hover {
            background-color: #f8f9fa;
            color: #495057;
        }
        
        .pdf-delete-btn {
            color: #dc3545;
        }
        
        .pdf-delete-btn:hover {
            background-color: #fff5f5;
            color: #c82333;
        }
        
        .pdf-merge-btn {
            background-color: #e5332d;
            color: white;
            border: none;
            padding: 15px 50px;
            font-size: 1.2rem;
            border-radius: 5px;
            cursor: pointer;
            width: 100%;
            margin-top: 20px;
            transition: all 0.3s ease;
        }
        
        .pdf-merge-btn:hover:not(:disabled) {
            background-color: #c72a24;
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(229, 51, 45, 0.4);
        }
        
        .pdf-merge-btn:disabled {
            background-color: #dee2e6;
            cursor: not-allowed;
        }
        
        .pdf-processing {
            text-align: center;
            padding: 40px;
        }
        
        .pdf-processing .spinner-border {
            width: 3rem;
            height: 3rem;
            color: #e5332d;
        }
        
        .pdf-empty-state {
            text-align: center;
            padding: 40px;
            color: #6c757d;
        }
        
        .pdf-empty-state i {
            font-size: 3rem;
            margin-bottom: 15px;
            opacity: 0.5;
        }
        
        .pdf-info-banner {
            background-color: #fff3cd;
            border-left: 4px solid #ffc107;
            padding: 15px;
            margin-bottom: 20px;
            border-radius: 5px;
        }
        
        .pdf-success-banner {
            background-color: #d1e7dd;
            border-left: 4px solid #198754;
            padding: 15px;
            margin-bottom: 20px;
            border-radius: 5px;
        }
        
        .pdf-progress-container {
            margin: 30px 0;
        }
        
        .pdf-progress-bar-wrapper {
            background-color: #e9ecef;
            border-radius: 10px;
            height: 30px;
            overflow: hidden;
            position: relative;
        }
        
        .pdf-progress-bar {
            background-color: #e5332d;
            height: 100%;
            transition: width 0.3s ease;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-weight: 600;
            font-size: 0.9rem;
        }
        
        .pdf-progress-text {
            text-align: center;
            margin-top: 10px;
            color: #6c757d;
            font-size: 0.95rem;
        }
        
        .pdf-result-container {
            background: white;
            border-radius: 10px;
            padding: 30px;
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
        }
        
        .pdf-result-preview {
            background: #f8f9fa;
            border: 2px solid #dee2e6;
            border-radius: 8px;
            padding: 40px;
            text-align: center;
            margin-bottom: 20px;
        }
        
        .pdf-result-preview i {
            font-size: 5rem;
            color: #e5332d;
            margin-bottom: 15px;
        }
        
        .pdf-result-info {
            margin-bottom: 25px;
        }
        
        .pdf-result-info h4 {
            color: #212529;
            margin-bottom: 10px;
        }
        
        .pdf-result-info p {
            color: #6c757d;
            margin: 5px 0;
        }
        
        .pdf-action-buttons {
            display: flex;
            gap: 15px;
            flex-wrap: wrap;
        }
        
        .pdf-action-buttons button {
            flex: 1;
            min-width: 200px;
            padding: 15px 30px;
            font-size: 1.1rem;
            border-radius: 5px;
            border: none;
            cursor: pointer;
            transition: all 0.3s ease;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
        }
        
        .pdf-download-btn {
            background-color: #e5332d;
            color: white;
        }
        
        .pdf-download-btn:hover {
            background-color: #c72a24;
            transform: translateY(-2px);
            box-shadow: 0 4px 12px rgba(229, 51, 45, 0.3);
        }
        
        .pdf-preview-btn {
            background-color: #0d6efd;
            color: white;
        }
        
        .pdf-preview-btn:hover {
            background-color: #0b5ed7;
            transform: translateY(-2px);
            box-shadow: 0 4px 12px rgba(13, 110, 253, 0.3);
        }
        
        .pdf-new-merge-btn {
            background-color: #6c757d;
            color: white;
        }
        
        .pdf-new-merge-btn:hover {
            background-color: #5a6268;
            transform: translateY(-2px);
            box-shadow: 0 4px 12px rgba(108, 117, 125, 0.3);
        }
        
        .pdf-preview-modal {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-color: rgba(0, 0, 0, 0.8);
            z-index: 9999;
            overflow: auto;
        }
        
        .pdf-preview-modal.active {
            display: flex;
            align-items: center;
            justify-content: center;
        }
        
        .pdf-preview-content {
            background: white;
            border-radius: 10px;
            width: 90%;
            max-width: 1000px;
            max-height: 90vh;
            overflow: hidden;
            display: flex;
            flex-direction: column;
        }
        
        .pdf-preview-header {
            background-color: #e5332d;
            color: white;
            padding: 20px;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .pdf-preview-close {
            background: none;
            border: none;
            color: white;
            font-size: 1.5rem;
            cursor: pointer;
            padding: 5px 10px;
        }
        
        .pdf-preview-body {
            flex: 1;
            overflow: auto;
            padding: 20px;
        }
        
        .pdf-preview-iframe {
            width: 100%;
            height: 70vh;
            border: none;
            border-radius: 5px;
        }
        
        input[type="file"] {
            display: none;
        }
        
        /* Guide Section Styles */
        .pdf-guide-section {
            background: white;
            padding: 50px;
            border-radius: 10px;
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
        }
        
        .pdf-guide-title {
            color: #212529;
            font-size: 2rem;
            font-weight: 600;
            text-align: center;
            margin-bottom: 15px;
        }
        
        .pdf-guide-subtitle {
            color: #6c757d;
            font-size: 1.1rem;
            text-align: center;
            margin-bottom: 40px;
        }
        
        .pdf-steps-container {
            display: grid;
            gap: 30px;
        }
        
        .pdf-step-item {
            display: flex;
            gap: 25px;
            align-items: flex-start;
            padding: 25px;
            background: #f8f9fa;
            border-radius: 10px;
            border-left: 4px solid #e5332d;
            transition: all 0.3s ease;
        }
        
        .pdf-step-item:hover {
            box-shadow: 0 4px 15px rgba(229, 51, 45, 0.15);
            transform: translateX(5px);
        }
        
        .pdf-step-number {
            background-color: #e5332d;
            color: white;
            width: 50px;
            height: 50px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            font-weight: 700;
            flex-shrink: 0;
        }
        
        .pdf-step-content h4 {
            color: #212529;
            font-size: 1.3rem;
            font-weight: 600;
            margin-bottom: 10px;
        }
        
        .pdf-step-content p {
            color: #6c757d;
            font-size: 1rem;
            line-height: 1.6;
            margin: 0;
        }
        
        /* FAQ Section Styles */
        .pdf-faq-section {
            background-color: #f8f9fa;
            padding: 60px 0;
            margin-top: 50px;
        }
        
        .pdf-faq-title {
            color: #212529;
            font-size: 2rem;
            font-weight: 600;
            text-align: center;
            margin-bottom: 40px;
        }
        
        .pdf-faq-container {
            display: grid;
            gap: 15px;
        }
        
        .pdf-faq-item {
            background: white;
            border-radius: 8px;
            overflow: hidden;
            box-shadow: 0 2px 5px rgba(0,0,0,0.05);
            transition: all 0.3s ease;
        }
        
        .pdf-faq-item:hover {
            box-shadow: 0 4px 12px rgba(0,0,0,0.1);
        }
        
        .pdf-faq-question {
            width: 100%;
            background: white;
            border: none;
            padding: 20px 25px;
            text-align: left;
            font-size: 1.1rem;
            font-weight: 600;
            color: #212529;
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
            gap: 15px;
            transition: all 0.3s ease;
        }
        
        .pdf-faq-question:hover {
            background-color: #f8f9fa;
            color: #e5332d;
        }
        
        .pdf-faq-question i {
            color: #e5332d;
            font-size: 1rem;
            transition: transform 0.3s ease;
        }
        
        .pdf-faq-question.active i {
            transform: rotate(180deg);
        }
        
        .pdf-faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease, padding 0.3s ease;
            background-color: #fff;
        }
        
        .pdf-faq-answer.active {
            max-height: 500px;
            padding: 0 25px 20px 25px;
        }
        
        .pdf-faq-answer p {
            color: #6c757d;
            font-size: 1rem;
            line-height: 1.6;
            margin: 0;
        }
        
        @media (max-width: 768px) {
            .pdf-action-buttons {
                flex-direction: column;
            }
            
            .pdf-action-buttons button {
                min-width: 100%;
            }
            
            .pdf-guide-section {
                padding: 30px 20px;
            }
            
            .pdf-step-item {
                flex-direction: column;
                text-align: center;
            }
            
            .pdf-step-number {
                margin: 0 auto;
            }
            
            .pdf-guide-title,
            .pdf-faq-title {
                font-size: 1.5rem;
            }
        }