:root {
            --primary-color: #1b1464;
            --secondary-color: #244fba;
            --accent-color: #667eea;
            --gradient-1: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            --gradient-2: linear-gradient(135deg, #1b1464 0%, #244fba 100%);
            --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
            --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.15);
            --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.2);
            --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }

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

        body {
            font-family: 'Poppins', sans-serif;
            background: var(--gradient-1);
            /* min-height: 100vh; */
            overflow-x: hidden;
        }

        /* Header */
        .header {
            backdrop-filter: blur(20px);
            box-shadow: var(--shadow-md);
            position: static!important;
            top: 0;
            z-index: 1000;
            animation: slideDown 0.5s ease-out;
        }

        @keyframes slideDown {
            from {
                transform: translateY(-100%);
            }

            to {
                transform: translateY(0);
            }
        }

        .header-content {
            max-width: 1400px;
            margin: 0 auto;
            padding: 20px 30px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
            gap: 15px;
        }

        .logo-section {
            display: flex;
            align-items: center;
            gap: 15px;
        }

        .logo-icon {
            width: 50px;
            height: 50px;
            background: var(--gradient-2);
            border-radius: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 24px;
            box-shadow: var(--shadow-sm);
        }

        .logo-text {
            font-size: 1.4rem;
            font-weight: 700;
            color: var(--primary-color);
            line-height: 1.2;
        }

        .logo-subtitle {
            font-size: 0.75rem;
            color: var(--secondary-color);
            font-weight: 400;
        }

        .back-btn {
            padding: 12px 28px;
            background: var(--gradient-2);
            color: white;
            text-decoration: none;
            border-radius: 50px;
            transition: var(--transition);
            font-weight: 600;
            font-size: 0.9rem;
            display: flex;
            align-items: center;
            gap: 8px;
            box-shadow: var(--shadow-sm);
        }

        .back-btn:hover {
            transform: translateY(-2px);
            box-shadow: var(--shadow-lg);
        }

        /* Main Content */
        .container {
            max-width: 1400px;
            margin: 0 auto;
            padding: 40px 20px;
        }

        .page-header {
            text-align: center;
            margin-bottom: 40px;
            animation: fadeInUp 0.8s ease-out;
        }

        @keyframes fadeInUp {
            from {
                opacity: 0;
                transform: translateY(30px);
            }

            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .page-title {
            font-size: clamp(2rem, 5vw, 3.5rem);
            font-weight: 700;
            color: white;
            text-shadow: 2px 4px 8px rgba(0, 0, 0, 0.3);
            margin-bottom: 10px;
        }

        .page-subtitle {
            font-size: clamp(1rem, 2vw, 1.3rem);
            color: rgba(255, 255, 255, 0.95);
            font-weight: 300;
        }

        /* Viewer Card */
        .viewer-card {
            background: white;
            border-radius: 24px;
            padding: clamp(20px, 4vw, 40px);
            box-shadow: var(--shadow-lg);
            animation: scaleIn 0.6s ease-out 0.2s backwards;
        }

        @keyframes scaleIn {
            from {
                opacity: 0;
                transform: scale(0.95);
            }

            to {
                opacity: 1;
                transform: scale(1);
            }
        }

        /* PDF Viewer */
        .pdf-viewer {
            background: #f8f9fa;
            border-radius: 16px;
            overflow: hidden;
            position: relative;
            /* min-height: 600px; */
        }

        .pdf-container {
            display: flex;
            justify-content: center;
            align-items: center;
            padding: 20px;
            /* min-height: 600px; */
        }

        .pdf-page {
            max-width: 100%;
            height: auto;
            box-shadow: var(--shadow-lg);
            border-radius: 8px;
            transition: var(--transition);
        }

        /* Thumbnail Sidebar */
        .thumbnail-sidebar {
            position: fixed;
            right: -280px;
            top: 90px;
            width: 260px;
            /* height: calc(100vh - 110px); */
            background: white;
            box-shadow: var(--shadow-lg);
            border-radius: 20px 0 0 20px;
            padding: 20px;
            overflow-y: auto;
            transition: var(--transition);
            z-index: 999;
        }

        .thumbnail-sidebar.active {
            right: 0;
        }

        .thumbnail-toggle {
            position: fixed;
            right: 20px;
            top: 110px;
            width: 50px;
            height: 50px;
            background: var(--gradient-2);
            color: white;
            border: none;
            border-radius: 50%;
            cursor: pointer;
            box-shadow: var(--shadow-md);
            font-size: 20px;
            z-index: 1000;
            transition: var(--transition);
        }

        .thumbnail-toggle:hover {
            transform: scale(1.1);
        }

        .thumbnail-item {
            margin-bottom: 15px;
            cursor: pointer;
            border: 3px solid transparent;
            border-radius: 8px;
            overflow: hidden;
            transition: var(--transition);
            position: relative;
        }

        .thumbnail-item:hover {
            border-color: var(--accent-color);
        }

        .thumbnail-item.active {
            border-color: var(--secondary-color);
            box-shadow: var(--shadow-md);
        }

        .thumbnail-canvas {
            width: 100%;
            display: block;
        }

        .thumbnail-number {
            position: absolute;
            bottom: 5px;
            right: 5px;
            background: rgba(0, 0, 0, 0.7);
            color: white;
            padding: 2px 8px;
            border-radius: 4px;
            font-size: 0.75rem;
        }

        /* Controls Bar */
        .controls-bar {
            display: flex;
            justify-content: space-between;
            align-items: center;
            gap: 15px;
            margin-top: 30px;
            flex-wrap: wrap;
            padding: 20px;
            background: linear-gradient(135deg, rgba(102, 126, 234, 0.1) 0%, rgba(118, 75, 162, 0.1) 100%);
            border-radius: 16px;
        }

        .controls-group {
            display: flex;
            gap: 10px;
            align-items: center;
            flex-wrap: wrap;
        }

        .control-btn {
            padding: 12px 24px;
            background: var(--gradient-2);
            color: white;
            border: none;
            border-radius: 50px;
            cursor: pointer;
            font-weight: 600;
            font-size: 0.9rem;
            transition: var(--transition);
            display: flex;
            align-items: center;
            gap: 8px;
            box-shadow: var(--shadow-sm);
            white-space: nowrap;
        }

        .control-btn:hover:not(:disabled) {
            transform: translateY(-2px);
            box-shadow: var(--shadow-md);
        }

        .control-btn:disabled {
            opacity: 0.5;
            cursor: not-allowed;
        }

        .control-btn.icon-only {
            padding: 12px;
            width: 45px;
            height: 45px;
            justify-content: center;
        }

        .page-indicator {
            padding: 12px 24px;
            background: white;
            border-radius: 50px;
            font-weight: 600;
            color: var(--primary-color);
            border: 2px solid var(--accent-color);
            white-space: nowrap;
        }

        .zoom-controls {
            display: flex;
            align-items: center;
            gap: 10px;
            background: white;
            padding: 8px 16px;
            border-radius: 50px;
            box-shadow: var(--shadow-sm);
        }

        .zoom-btn {
            width: 40px;
            height: 40px;
            background: var(--gradient-1);
            color: white;
            border: none;
            border-radius: 50%;
            cursor: pointer;
            font-size: 1.2rem;
            transition: var(--transition);
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .zoom-btn:hover {
            transform: scale(1.1);
        }

        .zoom-level {
            font-weight: 600;
            color: var(--primary-color);
            min-width: 60px;
            text-align: center;
        }

        /* Loading Spinner */
        .loading-overlay {
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: rgba(255, 255, 255, 0.95);
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            z-index: 100;
        }

        .spinner {
            width: 60px;
            height: 60px;
            border: 4px solid #f3f3f3;
            border-top: 4px solid var(--secondary-color);
            border-radius: 50%;
            animation: spin 1s linear infinite;
        }

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

            100% {
                transform: rotate(360deg);
            }
        }

        .loading-text {
            margin-top: 20px;
            color: var(--primary-color);
            font-weight: 500;
        }

        /* Fullscreen Mode */
        .viewer-card.fullscreen {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            border-radius: 0;
            z-index: 9999;
            padding: 20px;
        }

        /* .viewer-card.fullscreen .pdf-container {
            min-height: calc(100vh - 180px);
        } */

        /* Responsive Design */
        @media (max-width: 1024px) {
            .thumbnail-sidebar {
                width: 220px;
                right: -240px;
            }

            .controls-bar {
                justify-content: center;
            }
        }

        @media (max-width: 768px) {
            .header-content {
                padding: 15px 20px;
            }

            .logo-text {
                font-size: 1.1rem;
            }

            .logo-icon {
                width: 40px;
                height: 40px;
                font-size: 20px;
            }

            .container {
                padding: 30px 15px;
            }

            .thumbnail-sidebar {
                width: 100%;
                right: -100%;
                top: 0;
                /* height: 100vh; */
                border-radius: 0;
            }

            .thumbnail-toggle {
                right: 15px;
                top: 95px;
                width: 45px;
                height: 45px;
            }

            .controls-bar {
                padding: 15px;
                gap: 10px;
            }

            .control-btn {
                padding: 10px 18px;
                font-size: 0.85rem;
            }

            .control-btn .btn-text {
                display: none;
            }

            .control-btn.icon-only {
                padding: 10px;
                width: 40px;
                height: 40px;
            }

            .page-indicator {
                padding: 10px 16px;
                font-size: 0.85rem;
            }

            .pdf-container {
                padding: 10px;
                /* min-height: 500px; */
            }
        }

        @media (max-width: 480px) {
            .page-header {
                margin-bottom: 25px;
            }

            .viewer-card {
                border-radius: 16px;
            }

            .controls-group {
                width: 100%;
                justify-content: center;
            }

            .zoom-controls {
                width: 100%;
                justify-content: space-between;
            }
        }

        /* Print Styles */
        @media print {

            .header,
            .controls-bar,
            .thumbnail-sidebar,
            .thumbnail-toggle {
                display: none;
            }

            .viewer-card {
                box-shadow: none;
                padding: 0;
            }
        }

        /* Scrollbar Styling */
        .thumbnail-sidebar::-webkit-scrollbar {
            width: 8px;
        }

        .thumbnail-sidebar::-webkit-scrollbar-track {
            background: #f1f1f1;
            border-radius: 10px;
        }

        .thumbnail-sidebar::-webkit-scrollbar-thumb {
            background: var(--accent-color);
            border-radius: 10px;
        }

        .thumbnail-sidebar::-webkit-scrollbar-thumb:hover {
            background: var(--secondary-color);
        }
        /* Language Selector Styles */
        .language-selector {
            display: flex;
            justify-content: center;
            padding: 20px 0 10px;
            animation: fadeIn 0.5s ease-in;
        }

        .language-toggle {
            display: flex;
            gap: 8px;
            background: rgba(255, 255, 255, 0.95);
            padding: 6px;
            border-radius: 50px;
            box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
            backdrop-filter: blur(10px);
        }

        .lang-btn {
            padding: 10px 24px;
            border: none;
            background: transparent;
            color: var(--primary-color);
            font-weight: 600;
            font-size: 0.95rem;
            border-radius: 50px;
            cursor: pointer;
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            position: relative;
            overflow: hidden;
            font-family: 'Poppins', sans-serif;
        }

        .lang-btn::before {
            content: '';
            position: absolute;
            top: 50%;
            left: 50%;
            width: 0;
            height: 0;
            border-radius: 50%;
            background: var(--gradient-2);
            transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
            transform: translate(-50%, -50%);
            z-index: -1;
        }

        .lang-btn:hover::before {
            width: 150%;
            height: 300%;
        }

        .lang-btn:hover {
            color: white;
            transform: translateY(-2px);
        }

        .lang-btn.active {
            background: var(--gradient-2);
            color: white;
            box-shadow: 0 4px 15px rgba(36, 79, 186, 0.3);
            transform: scale(1.05);
        }

        .lang-btn.active::before {
            width: 0;
            height: 0;
        }

        @keyframes fadeIn {
            from {
                opacity: 0;
                transform: translateY(-10px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        /* Responsive Language Selector */
        @media (max-width: 768px) {
            .language-selector {
                padding: 15px 0 8px;
            }

            .language-toggle {
                gap: 5px;
                padding: 4px;
            }

            .lang-btn {
                padding: 8px 18px;
                font-size: 0.85rem;
            }
        }

        @media (max-width: 480px) {
            .lang-btn {
                padding: 6px 14px;
                font-size: 0.8rem;
            }
        }