:root {
            --primary-color: #2563eb;
            --card-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
            --card-shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
            --border-radius: 0.75rem;
            --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
        }

        body {
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
            line-height: 1.6;
            color: #1e293b;
            background-color: #f8fafc;
        }

        .navbar {
            backdrop-filter: blur(10px);
            background: linear-gradient(135deg, #1e293b 0%, #334155 100%) !important;
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
            border-bottom: 1px solid rgba(255, 255, 255, 0.1);
        }

        .navbar-brand {
            font-weight: 700;
            font-size: 1.5rem;
            letter-spacing: -0.025em;
        }

        .container {
            max-width: 1400px;
        }

        /* Statistics Cards */
        .stats-card {
            border: none;
            border-radius: var(--border-radius);
            box-shadow: var(--card-shadow);
            transition: var(--transition);
            overflow: hidden;
            position: relative;
        }

        .stats-card::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 4px;
            background: linear-gradient(90deg, rgba(255,255,255,0.3), rgba(255,255,255,0.1));
        }

        .stats-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--card-shadow-hover);
        }

        .stats-card-total {
            background: linear-gradient(135deg, #64748b 0%, #475569 100%);
            color: white;
        }

        .stats-card-introduce {
            background: linear-gradient(135deg, #8b5cf6 0%, #7c3aed 100%);
            color: white;
        }

        .stats-card-finetune {
            background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
            color: white;
        }

        .stats-card-apply {
            background: linear-gradient(135deg, #10b981 0%, #059669 100%);
            color: white;
        }

        .stats-card-china {
            background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
            color: white;
        }

        .stats-card h3 {
            font-size: 2.5rem;
            font-weight: 800;
            margin-bottom: 0.5rem;
            line-height: 1;
        }

        .stats-card p {
            font-size: 0.875rem;
            font-weight: 500;
            opacity: 0.9;
            margin: 0;
        }

        /* Chart Cards */
        .chart-card {
            border: none;
            border-radius: var(--border-radius);
            box-shadow: var(--card-shadow);
            transition: var(--transition);
            background: white;
        }

        .chart-card:hover {
            box-shadow: var(--card-shadow-hover);
        }

        .chart-card .card-header {
            background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
            border-bottom: 1px solid #e2e8f0;
            border-radius: var(--border-radius) var(--border-radius) 0 0;
            padding: 1.25rem 1.5rem;
        }

        .chart-card .card-header h5 {
            margin: 0;
            font-weight: 600;
            color: #1e293b;
            font-size: 1.125rem;
        }

        .chart-container {
            height: 380px;
            padding: 1rem;
        }

        /* Filter Section */
        .filter-section {
            background: white;
            border-radius: var(--border-radius);
            padding: 2rem;
            margin-bottom: 2rem;
            box-shadow: var(--card-shadow);
            border: 1px solid #e2e8f0;
        }

        .filter-section h5 {
            color: #1e293b;
            font-weight: 600;
            margin-bottom: 1.5rem;
            font-size: 1.25rem;
        }

        .form-label {
            font-weight: 500;
            color: #374151;
            margin-bottom: 0.5rem;
            font-size: 0.875rem;
        }

        .form-select, .form-control {
            border: 1px solid #d1d5db;
            border-radius: 0.5rem;
            padding: 0.75rem 1rem;
            font-size: 0.875rem;
            transition: var(--transition);
        }

        .form-select:focus, .form-control:focus {
            border-color: var(--primary-color);
            box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
        }

        /* Article Cards */
        .article-card {
            border: none;
            border-radius: var(--border-radius);
            box-shadow: var(--card-shadow);
            transition: var(--transition);
            height: 100%;
            background: white;
            overflow: hidden;
        }

        .article-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--card-shadow-hover);
        }

        .article-card .card-body {
            padding: 0.5rem;
            display: flex;
            flex-direction: column;
            height: 100%;
            justify-content: space-between;
        }

        .article-card .card-title {
            font-size: 0.95rem;
            font-weight: 700;
            line-height: 1.2;
            margin-bottom: 0.375rem;
            color: #1e293b;
        }

        .article-card .card-title a {
            color: inherit;
            text-decoration: none;
            transition: var(--transition);
        }

        .article-card .card-title a:hover {
            color: var(--primary-color);
        }

        .article-header {
            flex-shrink: 0;
        }

        .article-content {
            max-height: 300px;
            overflow-y: auto;
            font-size: 0.8rem;
            line-height: 1.4;
            color: #64748b;
            flex-grow: 1;
            margin-top: auto;
        }

        .article-content::-webkit-scrollbar {
            width: 4px;
        }

        .article-content::-webkit-scrollbar-track {
            background: #f1f5f9;
            border-radius: 2px;
        }

        .article-content::-webkit-scrollbar-thumb {
            background: #cbd5e1;
            border-radius: 2px;
        }

        /* Badges */
        .classification-badge {
            font-size: 0.7rem;
            font-weight: 500;
            padding: 0.25rem 0.5rem;
            border-radius: 0.375rem;
        }

        .journal-badge {
            background: linear-gradient(135deg, #64748b 0%, #475569 100%);
            color: white;
            font-size: 0.7rem;
            font-weight: 500;
            padding: 0.25rem 0.5rem;
            border-radius: 0.375rem;
        }

        .badge-introduce {
            background: linear-gradient(135deg, #8b5cf6 0%, #7c3aed 100%) !important;
            color: white !important;
        }

        .badge-finetune {
            background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%) !important;
            color: white !important;
        }

        .badge-apply {
            background: linear-gradient(135deg, #10b981 0%, #059669 100%) !important;
            color: white !important;
        }

        /* Badge Tooltips */
        .badge {
            cursor: help;
        }

        .badge-tooltip {
            position: fixed;
            background: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #334155 100%);
            color: #f8fafc;
            padding: 0.875rem 1rem;
            border-radius: 0.5rem;
            font-size: 0.75rem;
            line-height: 1.5;
            max-width: 300px;
            min-width: 200px;
            width: 250px;
            z-index: 9999;
            opacity: 0;
            visibility: hidden;
            transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
            box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
            pointer-events: none;
            border: 1px solid rgba(148, 163, 184, 0.3);
            backdrop-filter: blur(8px);
        }

        .badge-tooltip::before {
            content: '';
            position: absolute;
            top: 100%;
            left: 50%;
            transform: translateX(-50%);
            width: 0;
            height: 0;
            border-left: 5px solid transparent;
            border-right: 5px solid transparent;
            border-top: 5px solid #1e293b;
        }


        /* Loading State */
        .loading {
            text-align: center;
            padding: 4rem 2rem;
            color: #64748b;
        }

        .spinner-border {
            width: 3rem;
            height: 3rem;
            border-width: 0.3em;
            color: var(--primary-color);
        }

        /* Articles Container */
        .articles-container {
            min-height: 500px;
        }

        #articles-container {
            display: flex !important;
            flex-wrap: wrap;
            gap: 0.125rem;
        }

        #articles-container .col-md-6,
        #articles-container .col-lg-3,
        #articles-container .col-lg-4 {
            flex: 0 0 calc(25% - 0.09375rem);
            max-width: calc(25% - 0.09375rem);
            margin-bottom: 0.25rem;
        }

        /* Pagination */
        .pagination {
            border-radius: 0.5rem;
            box-shadow: var(--card-shadow);
        }

        .page-link {
            border: none;
            color: #64748b;
            padding: 0.75rem 1rem;
            font-weight: 500;
            transition: var(--transition);
        }

        .page-link:hover {
            background-color: #f1f5f9;
            color: var(--primary-color);
        }

        .page-item.active .page-link {
            background-color: var(--primary-color);
            color: white;
        }

        /* Footer */
        footer {
            background: linear-gradient(135deg, #1e293b 0%, #334155 100%) !important;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
        }

        /* Responsive Design */
        @media (max-width: 1199.98px) {
            #articles-container .col-md-6,
            #articles-container .col-lg-3,
            #articles-container .col-lg-4 {
                flex: 0 0 calc(33.333333% - 0.0833rem);
                max-width: calc(33.333333% - 0.0833rem);
                margin-bottom: 0.25rem;
            }
            
            .stats-col {
                flex: 0 0 25%;
                max-width: 25%;
            }
        }

        @media (max-width: 991.98px) {
            .stats-col {
                flex: 0 0 33.333333%;
                max-width: 33.333333%;
            }
            
            .filter-section {
                padding: 1.5rem;
            }
        }

        @media (max-width: 767.98px) {
            #articles-container .col-md-6,
            #articles-container .col-lg-3,
            #articles-container .col-lg-4 {
                flex: 0 0 calc(50% - 0.0625rem);
                max-width: calc(50% - 0.0625rem);
                margin-bottom: 0.25rem;
            }
            
            .stats-col {
                flex: 0 0 50%;
                max-width: 50%;
            }
            
            .stats-card h3 {
                font-size: 2rem;
            }
            
            .filter-section {
                padding: 1rem;
            }
            
            .chart-container {
                height: 250px;
            }
        }

        @media (max-width: 575.98px) {
            #articles-container .col-md-6,
            #articles-container .col-lg-3,
            #articles-container .col-lg-4 {
                flex: 0 0 100%;
                max-width: 100%;
                margin-bottom: 0.25rem;
            }
            
            .stats-col {
                flex: 0 0 100%;
                max-width: 100%;
            }
            
            .stats-card h3 {
                font-size: 1.75rem;
            }
            
            .container {
                padding-left: 1rem;
                padding-right: 1rem;
            }
        }

        /* Article Details Modal */
        .article-modal {
            z-index: 1055;
        }

        .article-modal .modal-dialog {
            max-width: 90vw;
            max-height: 95vh;
            height: 95vh;
        }

        .article-modal .modal-content {
            border-radius: var(--border-radius);
            box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
            border: 1px solid rgba(148, 163, 184, 0.2);
            height: 100%;
            display: flex;
            flex-direction: column;
        }

        .article-modal .modal-header {
            background: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #334155 100%);
            color: #f8fafc;
            border-bottom: 1px solid rgba(148, 163, 184, 0.3);
            border-radius: var(--border-radius) var(--border-radius) 0 0;
            padding: 1.5rem 2rem;
        }

        .article-modal .modal-header .modal-title {
            color: #f8fafc;
            font-weight: 700;
            font-size: 1.25rem;
        }

        .article-modal .modal-body {
            max-height: 85vh;
            height: 85vh;
            overflow-y: auto;
            padding: 2rem;
            background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
            flex: 1 1 auto;
        }

        .article-modal .modal-body::-webkit-scrollbar {
            width: 8px;
        }

        .article-modal .modal-body::-webkit-scrollbar-track {
            background: #f1f5f9;
            border-radius: 4px;
        }

        .article-modal .modal-body::-webkit-scrollbar-thumb {
            background: linear-gradient(135deg, #cbd5e1 0%, #94a3b8 100%);
            border-radius: 4px;
        }

        .article-modal .modal-body::-webkit-scrollbar-thumb:hover {
            background: linear-gradient(135deg, #94a3b8 0%, #64748b 100%);
        }

        .article-details-section {
            margin-bottom: 2rem;
            padding: 1.75rem;
            background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
            border-radius: var(--border-radius);
            border: 1px solid rgba(148, 163, 184, 0.2);
            box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.05);
            transition: all 0.2s ease;
        }

        .article-details-section:hover {
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
            border-color: rgba(148, 163, 184, 0.3);
        }

        .article-details-section h6 {
            color: #0f172a;
            font-weight: 700;
            margin-bottom: 1.25rem;
            font-size: 1.125rem;
            border-bottom: 2px solid #e2e8f0;
            padding-bottom: 0.5rem;
        }

        .generated-badge {
            display: inline-block;
            font-size: 0.75rem;
            font-weight: 500;
            color: #64748b;
            background-color: #f1f5f9;
            padding: 0.25rem 0.5rem;
            border-radius: 0.375rem;
            margin-left: 0.5rem;
            vertical-align: middle;
            border: 1px solid #e2e8f0;
        }

        .article-details-section p {
            margin-bottom: 0.75rem;
            line-height: 1.7;
            color: #374151;
        }

        .article-details-section p strong {
            color: #1e293b;
            font-weight: 600;
        }


        .annotation-code {
            display: inline-block;
            background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
            color: #ffffff;
            padding: 0.375rem 0.625rem;
            border-radius: 0.5rem;
            font-size: 0.75rem;
            font-weight: 700;
            margin-right: 0.25rem;
            margin-left: 0.25rem;
            cursor: help;
            position: relative;
            transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
            vertical-align: baseline;
            box-shadow: 0 2px 4px rgba(59, 130, 246, 0.3);
        }

        .annotation-code:hover {
            background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
            transform: scale(1.05);
            box-shadow: 0 4px 8px rgba(59, 130, 246, 0.4);
        }

        .annotation-tooltip {
            position: absolute;
            bottom: calc(100% + 8px);
            left: 50%;
            transform: translateX(-50%);
            background: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #334155 100%);
            color: #f8fafc;
            padding: 1.25rem 1.5rem;
            border-radius: 0.75rem;
            font-size: 0.8125rem;
            line-height: 1.6;
            max-width: 420px;
            min-width: 280px;
            width: 380px;
            z-index: 1000;
            opacity: 0;
            visibility: hidden;
            transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
            box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.15), 0 10px 10px -5px rgba(0, 0, 0, 0.08);
            pointer-events: none;
            border: 1px solid rgba(148, 163, 184, 0.3);
            backdrop-filter: blur(12px);
        }

        .annotation-tooltip::before {
            content: '';
            position: absolute;
            top: 100%;
            left: 50%;
            transform: translateX(-50%);
            width: 0;
            height: 0;
            border-left: 6px solid transparent;
            border-right: 6px solid transparent;
            border-top: 6px solid #1e293b;
        }

        .annotation-tooltip::after {
            content: '';
            position: absolute;
            top: 100%;
            left: 50%;
            transform: translateX(-50%);
            width: 0;
            height: 0;
            border-left: 7px solid transparent;
            border-right: 7px solid transparent;
            border-top: 7px solid rgba(0, 0, 0, 0.15);
            margin-top: 1px;
        }

        .annotation-code:hover .annotation-tooltip {
            opacity: 1;
            visibility: visible;
        }

        /* Responsive tooltip positioning */
        @media (max-width: 768px) {
            .annotation-tooltip {
                max-width: 360px;
                min-width: 240px;
                width: 320px;
                font-size: 0.75rem;
                padding: 1rem 1.25rem;
            }
        }

        /* Handle tooltips near screen edges */
        .annotation-code:nth-child(odd) .annotation-tooltip {
            left: auto;
            right: 0;
            transform: none;
        }

        .annotation-code:nth-child(odd) .annotation-tooltip::before,
        .annotation-code:nth-child(odd) .annotation-tooltip::after {
            left: auto;
            right: 20px;
            transform: none;
        }


        .clickable-title {
            cursor: pointer;
            transition: var(--transition);
            color: var(--primary-color) !important;
        }

        .clickable-title:hover {
            color: var(--primary-color) !important;
            text-decoration: underline;
        }

        /* Utility Classes */
        .text-muted {
            color: #64748b !important;
        }

        .mb-4 {
            margin-bottom: 2rem !important;
        }

        .mt-4 {
            margin-top: 2rem !important;
        }

        .mt-5 {
            margin-top: 3rem !important;
        }