/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #ffffff;
}

.container {
    width: 100%;
    margin: 0;
    padding: 0;
}

/* Header Styles */
.header {
    background: linear-gradient(135deg, #3b4d8f 0%, #2d3a6b 100%);
    color: white;
    padding: 1rem 0;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
    padding: 0 1rem;
    max-width: none;
}

.logo-section {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.flag-icon {
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.2));
}

.flag-image {
    width: 40px;
    height: auto;
    border-radius: 4px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.title-section h1 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.title-section p {
    font-size: 0.9rem;
    opacity: 0.9;
    font-weight: 300;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.language-switcher {
    display: flex;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    padding: 4px;
    backdrop-filter: blur(10px);
}

.lang-btn {
    background: transparent;
    border: none;
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.lang-btn:hover {
    background: rgba(255, 255, 255, 0.1);
}

.lang-btn.active {
    background: rgba(255, 255, 255, 0.2);
    font-weight: 500;
}

.search-btn {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    backdrop-filter: blur(10px);
}

.search-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-1px);
}

.mobile-menu-toggle {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: none;
    align-items: center;
    gap: 0.5rem;
    backdrop-filter: blur(10px);
}

.mobile-menu-toggle:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-1px);
}

.mobile-menu-toggle i {
    font-size: 1rem;
}

/* Main Content */
.main-content {
    min-height: calc(100vh - 200px);
    padding: 0;
}

.content-wrapper {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 0;
    height: calc(100vh - 200px);
    max-width: none;
}

/* Sidebar */
.sidebar {
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    overflow: hidden;
    height: fit-content;
    max-height: calc(100vh - 250px);
    position: sticky;
    top: 120px;
}

.sidebar-header {
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    padding: 1.5rem;
    border-bottom: 1px solid #e2e8f0;
}

.sidebar-header h3 {
    color: #2d3748;
    font-weight: 600;
    font-size: 1.1rem;
}

.document-nav {
    padding: 1rem;
    overflow-y: auto;
    max-height: calc(100vh - 350px);
}

.nav-section h4 {
    color: #4a5568;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.document-list {
    list-style: none;
}

.document-item {
    margin-bottom: 0.5rem;
}

.document-link {
    display: block;
    padding: 0.75rem 1rem;
    color: #4a5568;
    text-decoration: none;
    border-radius: 8px;
    transition: all 0.3s ease;
    font-size: 0.9rem;
    border-left: 3px solid transparent;
}

.document-link:hover {
    background: #f7fafc;
    color: #3b4d8f;
    border-left-color: #3b4d8f;
    transform: translateX(4px);
}

.document-link.active {
    background: linear-gradient(135deg, #3b4d8f 0%, #2d3a6b 100%);
    color: white;
    border-left-color: #ffd700;
    font-weight: 500;
}

/* Viewer Section */
.viewer-section {
    background: white;
    border-radius: 0;
    box-shadow: none;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    height: calc(100vh - 250px);
}

.viewer-header {
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    padding: 1.5rem;
    border-bottom: 1px solid #e2e8f0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.document-info h2 {
    color: #2d3748;
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.document-meta {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.meta-item {
    background: #e2e8f0;
    color: #4a5568;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
}

.viewer-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: white;
    padding: 0.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.control-btn {
    background: transparent;
    border: 1px solid #e2e8f0;
    color: #4a5568;
    padding: 0.5rem;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s ease;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.control-btn:hover {
    background: #f7fafc;
    border-color: #3b4d8f;
    color: #3b4d8f;
}

.zoom-level {
    padding: 0.5rem 0.75rem;
    font-size: 0.9rem;
    font-weight: 500;
    color: #4a5568;
    min-width: 50px;
    text-align: center;
}

/* PDF Viewer Container */
.pdf-viewer-container {
    flex: 1;
    position: relative;
    overflow: hidden;
}

.pdf-viewer {
    width: 100%;
    height: 100%;
    border: none;
}

.hidden {
    display: none !important;
}

/* Welcome Screen */
.welcome-screen {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
}

.welcome-content {
    text-align: center;
    max-width: 500px;
    padding: 2rem;
}

.welcome-icon {
    font-size: 4rem;
    color: #3b4d8f;
    margin-bottom: 1.5rem;
}

.welcome-content h3 {
    color: #2d3748;
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.welcome-content p {
    color: #4a5568;
    font-size: 1.1rem;
    margin-bottom: 2rem;
    line-height: 1.6;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin-top: 2rem;
}

.feature {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: #4a5568;
    font-size: 0.9rem;
}

.feature i {
    color: #3b4d8f;
    font-size: 1.2rem;
}

/* Loading Screen */
.loading-screen {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    background: #f8fafc;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 4px solid #e2e8f0;
    border-top: 4px solid #3b4d8f;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

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

/* Footer */
.footer {
    background: #2d3748;
    color: white;
    padding: 3rem 0 1rem;
    margin-top: 4rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
    padding: 0 1rem;
    max-width: none;
}

.footer-section h4 {
    color: #ffd700;
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.footer-section p {
    color: #a0aec0;
    line-height: 1.6;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: #a0aec0;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section ul li a:hover {
    color: #ffd700;
}

.footer-bottom {
    border-top: 1px solid #4a5568;
    padding-top: 1rem;
    text-align: center;
    color: #a0aec0;
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 1200px) {
    .main-content {
        padding: 0;
    }
    
    .content-wrapper {
        gap: 0;
    }
}

/* Tablet View (1024px and below) */
@media (max-width: 1024px) {
    .content-wrapper {
        grid-template-columns: 280px 1fr;
        gap: 1rem;
        padding: 0 1rem;
    }
    
    .sidebar {
        border-radius: 8px;
        margin-right: 0;
    }
    
    .viewer-section {
        border-radius: 8px;
        box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    }
    
    .header-content {
        padding: 0 1rem;
    }
    
    .title-section h1 {
        font-size: 1.6rem;
    }
    
    .viewer-header {
        padding: 1rem;
    }
    
    .document-meta {
        flex-wrap: wrap;
    }
}

/* Mobile Landscape and Small Tablets (768px and below) */
@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: flex;
        order: 0;
    }
    
    .content-wrapper {
        grid-template-columns: 1fr;
        height: auto;
        gap: 1rem;
        padding: 0 0.5rem;
    }
    
    .sidebar {
        position: static;
        max-height: 300px;
        margin-bottom: 1rem;
        order: 1;
        transition: all 0.3s ease;
    }
    
    .sidebar.mobile-hidden {
        display: none;
    }
    
    .viewer-section {
        height: 75vh;
        min-height: 500px;
        order: 2;
    }
    
    .viewer-section.sidebar-hidden {
        height: 85vh;
    }
    
    .header-content {
        flex-direction: column;
        text-align: center;
        gap: 1rem;
        padding: 0 1rem;
    }
    
    .header-controls {
        width: 100%;
        justify-content: center;
        flex-wrap: wrap;
    }
    
    .language-switcher {
        order: 1;
    }
    
    .search-btn {
        order: 2;
    }
    
    .viewer-header {
        flex-direction: column;
        align-items: stretch;
        gap: 1rem;
        padding: 1rem;
    }
    
    .viewer-controls {
        align-self: stretch;
        justify-content: center;
        flex-wrap: wrap;
    }
    
    .document-nav {
        max-height: 200px;
    }
    
    .welcome-content {
        padding: 1.5rem;
    }
    
    .welcome-content h3 {
        font-size: 1.5rem;
    }
    
    .welcome-content p {
        font-size: 1rem;
    }
}

/* Mobile Portrait (480px and below) */
@media (max-width: 480px) {
    .main-content {
        padding: 0;
    }
    
    .content-wrapper {
        padding: 0 0.25rem;
        gap: 0.5rem;
    }
    
    .header-content {
        padding: 0 0.5rem;
        gap: 0.75rem;
    }
    
    .title-section h1 {
        font-size: 1.3rem;
        line-height: 1.3;
    }
    
    .title-section p {
        font-size: 0.8rem;
    }
    
    .flag-image {
        width: 32px;
    }
    
    .language-switcher {
        width: 100%;
        justify-content: center;
    }
    
    .lang-btn {
        padding: 0.4rem 0.8rem;
        font-size: 0.8rem;
    }
    
    .search-btn {
        padding: 0.4rem 0.8rem;
        font-size: 0.8rem;
    }
    
    .sidebar {
        max-height: 250px;
        border-radius: 6px;
    }
    
    .sidebar-header {
        padding: 1rem;
    }
    
    .sidebar-header h3 {
        font-size: 1rem;
    }
    
    .document-nav {
        padding: 0.75rem;
        max-height: 150px;
    }
    
    .document-link {
        padding: 0.6rem 0.8rem;
        font-size: 0.85rem;
    }
    
    .viewer-section {
        height: 70vh;
        min-height: 400px;
        border-radius: 6px;
    }
    
    .viewer-header {
        padding: 0.75rem;
    }
    
    .document-info h2 {
        font-size: 1.1rem;
    }
    
    .meta-item {
        font-size: 0.75rem;
        padding: 0.2rem 0.6rem;
    }
    
    .control-btn {
        width: 32px;
        height: 32px;
        font-size: 0.8rem;
    }
    
    .zoom-level {
        font-size: 0.8rem;
        padding: 0.4rem 0.6rem;
        min-width: 45px;
    }
    
    .welcome-content {
        padding: 1rem;
    }
    
    .welcome-icon {
        font-size: 3rem;
        margin-bottom: 1rem;
    }
    
    .welcome-content h3 {
        font-size: 1.3rem;
        margin-bottom: 0.75rem;
    }
    
    .welcome-content p {
        font-size: 0.9rem;
        margin-bottom: 1.5rem;
    }
    
    .features {
        grid-template-columns: 1fr;
        gap: 0.75rem;
        margin-top: 1.5rem;
    }
    
    .feature {
        font-size: 0.85rem;
        justify-content: center;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
        padding: 0 0.5rem;
        gap: 1.5rem;
    }
    
    .footer-section h4 {
        font-size: 1rem;
    }
    
    .footer-section p {
        font-size: 0.9rem;
    }
}

/* Extra Small Mobile (360px and below) */
@media (max-width: 360px) {
    .title-section h1 {
        font-size: 1.1rem;
    }
    
    .title-section p {
        font-size: 0.75rem;
    }
    
    .lang-btn {
        padding: 0.3rem 0.6rem;
        font-size: 0.75rem;
    }
    
    .search-btn {
        padding: 0.3rem 0.6rem;
        font-size: 0.75rem;
    }
    
    .viewer-section {
        height: 65vh;
        min-height: 350px;
    }
    
    .sidebar {
        max-height: 200px;
    }
    
    .document-nav {
        max-height: 120px;
    }
    
    .welcome-content h3 {
        font-size: 1.1rem;
    }
    
    .welcome-content p {
        font-size: 0.85rem;
    }
}

/* Print Styles - Hidden */
@media print {
    .header, .sidebar, .viewer-controls, .footer {
        display: none !important;
    }
    
    .content-wrapper {
        grid-template-columns: 1fr;
    }
    
    .viewer-section {
        height: 100vh;
    }
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb {
    background: #c1c1c1;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #a8a8a8;
}

/* Focus Styles for Accessibility */
.lang-btn:focus,
.search-btn:focus,
.control-btn:focus,
.document-link:focus {
    outline: 2px solid #ffd700;
    outline-offset: 2px;
}

/* Touch-friendly improvements for mobile */
@media (max-width: 768px) {
    /* Increase touch targets */
    .lang-btn,
    .search-btn,
    .control-btn,
    .document-link {
        min-height: 44px;
        min-width: 44px;
    }
    
    /* Prevent zoom on input focus */
    input, select, textarea {
        font-size: 16px;
    }
    
    /* Improve scrolling on mobile */
    .document-nav {
        -webkit-overflow-scrolling: touch;
        scroll-behavior: smooth;
    }
    
    /* Better mobile sidebar */
    .sidebar {
        border-radius: 8px;
        box-shadow: 0 2px 12px rgba(0, 0, 0, 0.1);
    }
    
    /* Mobile-optimized PDF viewer */
    .pdf-viewer-container {
        border-radius: 8px;
        overflow: hidden;
    }
    
    /* Improve mobile header spacing */
    .header {
        padding: 0.75rem 0;
    }
    
    /* Better mobile footer */
    .footer {
        padding: 2rem 0 1rem;
        margin-top: 2rem;
    }
}

/* Animation for smooth transitions */
.pdf-viewer,
.welcome-screen,
.loading-screen {
    transition: opacity 0.3s ease;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    .header {
        background: #000;
    }
    
    .document-link.active {
        background: #000;
        border-left-color: #fff;
    }
}

.title-section h1 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.title-section p {
    font-size: 0.9rem;
    opacity: 0.9;
    font-weight: 300;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.language-switcher {
    display: flex;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    padding: 4px;
    backdrop-filter: blur(10px);
}

.lang-btn {
    background: transparent;
    border: none;
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.lang-btn:hover {
    background: rgba(255, 255, 255, 0.1);
}

.lang-btn.active {
    background: rgba(255, 255, 255, 0.2);
    font-weight: 500;
}

.search-btn {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    backdrop-filter: blur(10px);
}

.search-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-1px);
}

/* Main Content */
.main-content {
    min-height: calc(100vh - 200px);
    padding: 0;
}

.content-wrapper {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 0;
    height: calc(100vh - 200px);
    max-width: none;
}

/* Sidebar */
.sidebar {
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    overflow: hidden;
    height: fit-content;
    max-height: calc(100vh - 250px);
    position: sticky;
    top: 120px;
}

.sidebar-header {
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    padding: 1.5rem;
    border-bottom: 1px solid #e2e8f0;
}

.sidebar-header h3 {
    color: #2d3748;
    font-weight: 600;
    font-size: 1.1rem;
}

.document-nav {
    padding: 1rem;
    overflow-y: auto;
    max-height: calc(100vh - 350px);
}

.nav-section h4 {
    color: #4a5568;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.document-list {
    list-style: none;
}

.document-item {
    margin-bottom: 0.5rem;
}

.document-link {
    display: block;
    padding: 0.75rem 1rem;
    color: #4a5568;
    text-decoration: none;
    border-radius: 8px;
    transition: all 0.3s ease;
    font-size: 0.9rem;
    border-left: 3px solid transparent;
}

.document-link:hover {
    background: #f7fafc;
    color: #3b4d8f;
    border-left-color: #3b4d8f;
    transform: translateX(4px);
}

.document-link.active {
    background: linear-gradient(135deg, #3b4d8f 0%, #2d3a6b 100%);
    color: white;
    border-left-color: #ffd700;
    font-weight: 500;
}

/* Viewer Section */
.viewer-section {
    background: white;
    border-radius: 0;
    box-shadow: none;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    height: calc(100vh - 250px);
}

.viewer-header {
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    padding: 1.5rem;
    border-bottom: 1px solid #e2e8f0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.document-info h2 {
    color: #2d3748;
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.document-meta {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.meta-item {
    background: #e2e8f0;
    color: #4a5568;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
}

.viewer-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: white;
    padding: 0.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.control-btn {
    background: transparent;
    border: 1px solid #e2e8f0;
    color: #4a5568;
    padding: 0.5rem;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s ease;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.control-btn:hover {
    background: #f7fafc;
    border-color: #3b4d8f;
    color: #3b4d8f;
}

.zoom-level {
    padding: 0.5rem 0.75rem;
    font-size: 0.9rem;
    font-weight: 500;
    color: #4a5568;
    min-width: 50px;
    text-align: center;
}

/* PDF Viewer Container */
.pdf-viewer-container {
    flex: 1;
    position: relative;
    overflow: hidden;
}

.pdf-viewer {
    width: 100%;
    height: 100%;
    border: none;
}

.hidden {
    display: none !important;
}

/* Welcome Screen */
.welcome-screen {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
}

.welcome-content {
    text-align: center;
    max-width: 500px;
    padding: 2rem;
}

.welcome-icon {
    font-size: 4rem;
    color: #3b4d8f;
    margin-bottom: 1.5rem;
}

.welcome-content h3 {
    color: #2d3748;
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.welcome-content p {
    color: #4a5568;
    font-size: 1.1rem;
    margin-bottom: 2rem;
    line-height: 1.6;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin-top: 2rem;
}

.feature {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: #4a5568;
    font-size: 0.9rem;
}

.feature i {
    color: #3b4d8f;
    font-size: 1.2rem;
}

/* Loading Screen */
.loading-screen {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    background: #f8fafc;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 4px solid #e2e8f0;
    border-top: 4px solid #3b4d8f;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

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

/* Footer */
.footer {
    background: #2d3748;
    color: white;
    padding: 3rem 0 1rem;
    margin-top: 4rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
    padding: 0 1rem;
    max-width: none;
}

.footer-section h4 {
    color: #ffd700;
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.footer-section p {
    color: #a0aec0;
    line-height: 1.6;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: #a0aec0;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section ul li a:hover {
    color: #ffd700;
}

.footer-bottom {
    border-top: 1px solid #4a5568;
    padding-top: 1rem;
    text-align: center;
    color: #a0aec0;
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 1200px) {
    .main-content {
        padding: 0;
    }
    
    .content-wrapper {
        gap: 0;
    }
}

@media (max-width: 1024px) {
    .content-wrapper {
        grid-template-columns: 250px 1fr;
    }
}

@media (max-width: 768px) {
    .content-wrapper {
        grid-template-columns: 1fr;
        height: auto;
    }
    
    .sidebar {
        position: static;
        max-height: none;
        margin-bottom: 0;
    }
    
    .viewer-section {
        height: 70vh;
    }
    
    .header-content {
        flex-direction: column;
        text-align: center;
    }
    
    .viewer-header {
        flex-direction: column;
        align-items: center;
    }
    
    .viewer-controls {
        align-self: stretch;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .main-content {
        padding: 0;
    }
    
    .header-content {
        padding: 0 0.5rem;
    }
    
    .title-section h1 {
        font-size: 1.4rem;
    }
    
    .language-switcher {
        width: 100%;
        justify-content: center;
    }
    
    .features {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
        padding: 0 0.5rem;
    }
}

/* Print Styles - Hidden */
@media print {
    .header, .sidebar, .viewer-controls, .footer {
        display: none !important;
    }
    
    .content-wrapper {
        grid-template-columns: 1fr;
    }
    
    .viewer-section {
        height: 100vh;
    }
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb {
    background: #c1c1c1;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #a8a8a8;
}

/* Focus Styles for Accessibility */
.lang-btn:focus,
.search-btn:focus,
.control-btn:focus,
.document-link:focus {
    outline: 2px solid #ffd700;
    outline-offset: 2px;
}

/* Animation for smooth transitions */
.pdf-viewer,
.welcome-screen,
.loading-screen {
    transition: opacity 0.3s ease;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    .header {
        background: #000;
    }
    
    .document-link.active {
        background: #000;
        border-left-color: #fff;
    }
}

.title-section h1 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.title-section p {
    font-size: 0.9rem;
    opacity: 0.9;
    font-weight: 300;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.language-switcher {
    display: flex;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    padding: 4px;
    backdrop-filter: blur(10px);
}

.lang-btn {
    background: transparent;
    border: none;
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.lang-btn:hover {
    background: rgba(255, 255, 255, 0.1);
}

.lang-btn.active {
    background: rgba(255, 255, 255, 0.2);
    font-weight: 500;
}

.search-btn {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    backdrop-filter: blur(10px);
}

.search-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-1px);
}

/* Main Content */
.main-content {
    min-height: calc(100vh - 200px);
    padding: 0;
}

.content-wrapper {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 0;
    height: calc(100vh - 200px);
    max-width: none;
}

/* Sidebar */
.sidebar {
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    overflow: hidden;
    height: fit-content;
    max-height: calc(100vh - 250px);
    position: sticky;
    top: 120px;
}

.sidebar-header {
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    padding: 1.5rem;
    border-bottom: 1px solid #e2e8f0;
}

.sidebar-header h3 {
    color: #2d3748;
    font-weight: 600;
    font-size: 1.1rem;
}

.document-nav {
    padding: 1rem;
    overflow-y: auto;
    max-height: calc(100vh - 350px);
}

.nav-section h4 {
    color: #4a5568;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.document-list {
    list-style: none;
}

.document-item {
    margin-bottom: 0.5rem;
}

.document-link {
    display: block;
    padding: 0.75rem 1rem;
    color: #4a5568;
    text-decoration: none;
    border-radius: 8px;
    transition: all 0.3s ease;
    font-size: 0.9rem;
    border-left: 3px solid transparent;
}

.document-link:hover {
    background: #f7fafc;
    color: #3b4d8f;
    border-left-color: #3b4d8f;
    transform: translateX(4px);
}

.document-link.active {
    background: linear-gradient(135deg, #3b4d8f 0%, #2d3a6b 100%);
    color: white;
    border-left-color: #ffd700;
    font-weight: 500;
}

/* Viewer Section */
.viewer-section {
    background: white;
    border-radius: 0;
    box-shadow: none;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    height: calc(100vh - 250px);
}

.viewer-header {
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    padding: 1.5rem;
    border-bottom: 1px solid #e2e8f0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.document-info h2 {
    color: #2d3748;
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.document-meta {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.meta-item {
    background: #e2e8f0;
    color: #4a5568;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
}

.viewer-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: white;
    padding: 0.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.control-btn {
    background: transparent;
    border: 1px solid #e2e8f0;
    color: #4a5568;
    padding: 0.5rem;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s ease;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.control-btn:hover {
    background: #f7fafc;
    border-color: #3b4d8f;
    color: #3b4d8f;
}

.zoom-level {
    padding: 0.5rem 0.75rem;
    font-size: 0.9rem;
    font-weight: 500;
    color: #4a5568;
    min-width: 50px;
    text-align: center;
}

/* PDF Viewer Container */
.pdf-viewer-container {
    flex: 1;
    position: relative;
    overflow: hidden;
}

.pdf-viewer {
    width: 100%;
    height: 100%;
    border: none;
}

.hidden {
    display: none !important;
}

/* Welcome Screen */
.welcome-screen {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
}

.welcome-content {
    text-align: center;
    max-width: 500px;
    padding: 2rem;
}

.welcome-icon {
    font-size: 4rem;
    color: #3b4d8f;
    margin-bottom: 1.5rem;
}

.welcome-content h3 {
    color: #2d3748;
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.welcome-content p {
    color: #4a5568;
    font-size: 1.1rem;
    margin-bottom: 2rem;
    line-height: 1.6;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin-top: 2rem;
}

.feature {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: #4a5568;
    font-size: 0.9rem;
}

.feature i {
    color: #3b4d8f;
    font-size: 1.2rem;
}

/* Loading Screen */
.loading-screen {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    background: #f8fafc;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 4px solid #e2e8f0;
    border-top: 4px solid #3b4d8f;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

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

/* Footer */
.footer {
    background: #2d3748;
    color: white;
    padding: 3rem 0 1rem;
    margin-top: 4rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
    padding: 0 1rem;
    max-width: none;
}

.footer-section h4 {
    color: #ffd700;
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.footer-section p {
    color: #a0aec0;
    line-height: 1.6;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: #a0aec0;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section ul li a:hover {
    color: #ffd700;
}

.footer-bottom {
    border-top: 1px solid #4a5568;
    padding-top: 1rem;
    text-align: center;
    color: #a0aec0;
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 1200px) {
    .main-content {
        padding: 0;
    }
    
    .content-wrapper {
        gap: 0;
    }
}

@media (max-width: 1024px) {
    .content-wrapper {
        grid-template-columns: 250px 1fr;
    }
}

@media (max-width: 768px) {
    .content-wrapper {
        grid-template-columns: 1fr;
        height: auto;
    }
    
    .sidebar {
        position: static;
        max-height: none;
        margin-bottom: 0;
    }
    
    .viewer-section {
        height: 70vh;
    }
    
    .header-content {
        flex-direction: column;
        text-align: center;
    }
    
    .viewer-header {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .viewer-controls {
        align-self: stretch;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .main-content {
        padding: 0;
    }
    
    .header-content {
        padding: 0 0.5rem;
    }
    
    .title-section h1 {
        font-size: 1.4rem;
    }
    
    .language-switcher {
        width: 100%;
        justify-content: center;
    }
    
    .features {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
        padding: 0 0.5rem;
    }
}

/* Print Styles - Hidden */
@media print {
    .header, .sidebar, .viewer-controls, .footer {
        display: none !important;
    }
    
    .content-wrapper {
        grid-template-columns: 1fr;
    }
    
    .viewer-section {
        height: 100vh;
    }
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb {
    background: #c1c1c1;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #a8a8a8;
}

/* Focus Styles for Accessibility */
.lang-btn:focus,
.search-btn:focus,
.control-btn:focus,
.document-link:focus {
    outline: 2px solid #ffd700;
    outline-offset: 2px;
}

/* Animation for smooth transitions */
.pdf-viewer,
.welcome-screen,
.loading-screen {
    transition: opacity 0.3s ease;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    .header {
        background: #000;
    }
    
    .document-link.active {
        background: #000;
        border-left-color: #fff;
    }
}

.title-section h1 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.title-section p {
    font-size: 0.9rem;
    opacity: 0.9;
    font-weight: 300;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.language-switcher {
    display: flex;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    padding: 4px;
    backdrop-filter: blur(10px);
}

.lang-btn {
    background: transparent;
    border: none;
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.lang-btn:hover {
    background: rgba(255, 255, 255, 0.1);
}

.lang-btn.active {
    background: rgba(255, 255, 255, 0.2);
    font-weight: 500;
}

.search-btn {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    backdrop-filter: blur(10px);
}

.search-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-1px);
}

/* Main Content */
.main-content {
    min-height: calc(100vh - 200px);
    padding: 0;
}

.content-wrapper {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 0;
    height: calc(100vh - 200px);
    max-width: none;
}

/* Sidebar */
.sidebar {
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    overflow: hidden;
    height: fit-content;
    max-height: calc(100vh - 250px);
    position: sticky;
    top: 120px;
}

.sidebar-header {
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    padding: 1.5rem;
    border-bottom: 1px solid #e2e8f0;
}

.sidebar-header h3 {
    color: #2d3748;
    font-weight: 600;
    font-size: 1.1rem;
}

.document-nav {
    padding: 1rem;
    overflow-y: auto;
    max-height: calc(100vh - 350px);
}

.nav-section h4 {
    color: #4a5568;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.document-list {
    list-style: none;
}

.document-item {
    margin-bottom: 0.5rem;
}

.document-link {
    display: block;
    padding: 0.75rem 1rem;
    color: #4a5568;
    text-decoration: none;
    border-radius: 8px;
    transition: all 0.3s ease;
    font-size: 0.9rem;
    border-left: 3px solid transparent;
}

.document-link:hover {
    background: #f7fafc;
    color: #3b4d8f;
    border-left-color: #3b4d8f;
    transform: translateX(4px);
}

.document-link.active {
    background: linear-gradient(135deg, #3b4d8f 0%, #2d3a6b 100%);
    color: white;
    border-left-color: #ffd700;
    font-weight: 500;
}

/* Viewer Section */
.viewer-section {
    background: white;
    border-radius: 0;
    box-shadow: none;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    height: calc(100vh - 250px);
}

.viewer-header {
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    padding: 1.5rem;
    border-bottom: 1px solid #e2e8f0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.document-info h2 {
    color: #2d3748;
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.document-meta {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.meta-item {
    background: #e2e8f0;
    color: #4a5568;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
}

.viewer-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: white;
    padding: 0.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.control-btn {
    background: transparent;
    border: 1px solid #e2e8f0;
    color: #4a5568;
    padding: 0.5rem;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s ease;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.control-btn:hover {
    background: #f7fafc;
    border-color: #3b4d8f;
    color: #3b4d8f;
}

.zoom-level {
    padding: 0.5rem 0.75rem;
    font-size: 0.9rem;
    font-weight: 500;
    color: #4a5568;
    min-width: 50px;
    text-align: center;
}

/* PDF Viewer Container */
.pdf-viewer-container {
    flex: 1;
    position: relative;
    overflow: hidden;
}

.pdf-viewer {
    width: 100%;
    height: 100%;
    border: none;
}

.hidden {
    display: none !important;
}

/* Welcome Screen */
.welcome-screen {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
}

.welcome-content {
    text-align: center;
    max-width: 500px;
    padding: 2rem;
}

.welcome-icon {
    font-size: 4rem;
    color: #3b4d8f;
    margin-bottom: 1.5rem;
}

.welcome-content h3 {
    color: #2d3748;
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.welcome-content p {
    color: #4a5568;
    font-size: 1.1rem;
    margin-bottom: 2rem;
    line-height: 1.6;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin-top: 2rem;
}

.feature {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: #4a5568;
    font-size: 0.9rem;
}

.feature i {
    color: #3b4d8f;
    font-size: 1.2rem;
}

/* Loading Screen */
.loading-screen {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    background: #f8fafc;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 4px solid #e2e8f0;
    border-top: 4px solid #3b4d8f;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

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

/* Footer */
.footer {
    background: #2d3748;
    color: white;
    padding: 3rem 0 1rem;
    margin-top: 4rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
    padding: 0 1rem;
    max-width: none;
}

.footer-section h4 {
    color: #ffd700;
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.footer-section p {
    color: #a0aec0;
    line-height: 1.6;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: #a0aec0;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section ul li a:hover {
    color: #ffd700;
}

.footer-bottom {
    border-top: 1px solid #4a5568;
    padding-top: 1rem;
    text-align: center;
    color: #a0aec0;
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 1200px) {
    .main-content {
        padding: 0;
    }
    
    .content-wrapper {
        gap: 0;
    }
}

@media (max-width: 1024px) {
    .content-wrapper {
        grid-template-columns: 250px 1fr;
    }
}

@media (max-width: 768px) {
    .content-wrapper {
        grid-template-columns: 1fr;
        height: auto;
    }
    
    .sidebar {
        position: static;
        max-height: none;
        margin-bottom: 0;
    }
    
    .viewer-section {
        height: 70vh;
    }
    
    .header-content {
        flex-direction: column;
        text-align: center;
    }
    
    .viewer-header {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .viewer-controls {
        align-self: stretch;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .main-content {
        padding: 0;
    }
    
    .header-content {
        padding: 0 0.5rem;
    }
    
    .title-section h1 {
        font-size: 1.4rem;
    }
    
    .language-switcher {
        width: 100%;
        justify-content: center;
    }
    
    .features {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
        padding: 0 0.5rem;
    }
}

/* Print Styles - Hidden */
@media print {
    .header, .sidebar, .viewer-controls, .footer {
        display: none !important;
    }
    
    .content-wrapper {
        grid-template-columns: 1fr;
    }
    
    .viewer-section {
        height: 100vh;
    }
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb {
    background: #c1c1c1;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #a8a8a8;
}

/* Focus Styles for Accessibility */
.lang-btn:focus,
.search-btn:focus,
.control-btn:focus,
.document-link:focus {
    outline: 2px solid #ffd700;
    outline-offset: 2px;
}

/* Animation for smooth transitions */
.pdf-viewer,
.welcome-screen,
.loading-screen {
    transition: opacity 0.3s ease;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    .header {
        background: #000;
    }
    
    .document-link.active {
        background: #000;
        border-left-color: #fff;
    }
}

.title-section h1 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.title-section p {
    font-size: 0.9rem;
    opacity: 0.9;
    font-weight: 300;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.language-switcher {
    display: flex;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    padding: 4px;
    backdrop-filter: blur(10px);
}

.lang-btn {
    background: transparent;
    border: none;
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.lang-btn:hover {
    background: rgba(255, 255, 255, 0.1);
}

.lang-btn.active {
    background: rgba(255, 255, 255, 0.2);
    font-weight: 500;
}

.search-btn {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    backdrop-filter: blur(10px);
}

.search-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-1px);
}

/* Main Content */
.main-content {
    min-height: calc(100vh - 200px);
    padding: 0;
}

.content-wrapper {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 0;
    height: calc(100vh - 200px);
    max-width: none;
}

/* Sidebar */
.sidebar {
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    overflow: hidden;
    height: fit-content;
    max-height: calc(100vh - 250px);
    position: sticky;
    top: 120px;
}

.sidebar-header {
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    padding: 1.5rem;
    border-bottom: 1px solid #e2e8f0;
}

.sidebar-header h3 {
    color: #2d3748;
    font-weight: 600;
    font-size: 1.1rem;
}

.document-nav {
    padding: 1rem;
    overflow-y: auto;
    max-height: calc(100vh - 350px);
}

.nav-section h4 {
    color: #4a5568;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.document-list {
    list-style: none;
}

.document-item {
    margin-bottom: 0.5rem;
}

.document-link {
    display: block;
    padding: 0.75rem 1rem;
    color: #4a5568;
    text-decoration: none;
    border-radius: 8px;
    transition: all 0.3s ease;
    font-size: 0.9rem;
    border-left: 3px solid transparent;
}

.document-link:hover {
    background: #f7fafc;
    color: #3b4d8f;
    border-left-color: #3b4d8f;
    transform: translateX(4px);
}

.document-link.active {
    background: linear-gradient(135deg, #3b4d8f 0%, #2d3a6b 100%);
    color: white;
    border-left-color: #ffd700;
    font-weight: 500;
}

/* Viewer Section */
.viewer-section {
    background: white;
    border-radius: 0;
    box-shadow: none;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    height: calc(100vh - 250px);
}

.viewer-header {
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    padding: 1.5rem;
    border-bottom: 1px solid #e2e8f0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.document-info h2 {
    color: #2d3748;
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.document-meta {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.meta-item {
    background: #e2e8f0;
    color: #4a5568;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
}

.viewer-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: white;
    padding: 0.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.control-btn {
    background: transparent;
    border: 1px solid #e2e8f0;
    color: #4a5568;
    padding: 0.5rem;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s ease;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.control-btn:hover {
    background: #f7fafc;
    border-color: #3b4d8f;
    color: #3b4d8f;
}

.zoom-level {
    padding: 0.5rem 0.75rem;
    font-size: 0.9rem;
    font-weight: 500;
    color: #4a5568;
    min-width: 50px;
    text-align: center;
}

/* PDF Viewer Container */
.pdf-viewer-container {
    flex: 1;
    position: relative;
    overflow: hidden;
}

.pdf-viewer {
    width: 100%;
    height: 100%;
    border: none;
}

.hidden {
    display: none !important;
}

/* Welcome Screen */
.welcome-screen {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
}

.welcome-content {
    text-align: center;
    max-width: 500px;
    padding: 2rem;
}

.welcome-icon {
    font-size: 4rem;
    color: #3b4d8f;
    margin-bottom: 1.5rem;
}

.welcome-content h3 {
    color: #2d3748;
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.welcome-content p {
    color: #4a5568;
    font-size: 1.1rem;
    margin-bottom: 2rem;
    line-height: 1.6;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin-top: 2rem;
}

.feature {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: #4a5568;
    font-size: 0.9rem;
}

.feature i {
    color: #3b4d8f;
    font-size: 1.2rem;
}

/* Loading Screen */
.loading-screen {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    background: #f8fafc;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 4px solid #e2e8f0;
    border-top: 4px solid #3b4d8f;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

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

/* Footer */
.footer {
    background: #2d3748;
    color: white;
    padding: 3rem 0 1rem;
    margin-top: 4rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
    padding: 0 1rem;
    max-width: none;
}

.footer-section h4 {
    color: #ffd700;
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.footer-section p {
    color: #a0aec0;
    line-height: 1.6;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: #a0aec0;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section ul li a:hover {
    color: #ffd700;
}

.footer-bottom {
    border-top: 1px solid #4a5568;
    padding-top: 1rem;
    text-align: center;
    color: #a0aec0;
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 1200px) {
    .main-content {
        padding: 0;
    }
    
    .content-wrapper {
        gap: 0;
    }
}

@media (max-width: 1024px) {
    .content-wrapper {
        grid-template-columns: 250px 1fr;
    }
}

@media (max-width: 768px) {
    .content-wrapper {
        grid-template-columns: 1fr;
        height: auto;
    }
    
    .sidebar {
        position: static;
        max-height: none;
        margin-bottom: 0;
    }
    
    .viewer-section {
        height: 70vh;
    }
    
    .header-content {
        flex-direction: column;
        text-align: center;
    }
    
    .viewer-header {
        flex-direction: column;
        align-items: center;
    }
}