:root {
            --primary-color: #0d6efd;
            --success-color: #198754;
            --warning-color: #ffc107;
            --danger-color: #dc3545;
            --light-color: #f8f9fa;
            --border-color: #dee2e6;
        }

        body {
            background-color: #f5f7fa;
        }

        .app-container {
            min-height: 100vh;
            display: flex;
            flex-direction: column;
        }

        .app-header {
            background: linear-gradient(135deg, #0d6efd 0%, #0dcaf0 100%);
            color: white;
            padding: 1.5rem;
            box-shadow: 0 2px 8px rgba(0,0,0,0.1);
        }

        .app-header h1 {
            font-size: 1.8rem;
            font-weight: 700;
            margin: 0;
        }

        .app-header p {
            margin: 0.5rem 0 0 0;
            font-size: 0.95rem;
            opacity: 0.95;
        }

        .content-wrapper {
            flex: 1;
            display: flex;
            gap: 1rem;
            padding: 1.5rem;
            max-width: 1600px;
            width: 100%;
            margin: 0 auto;
        }

        /* Left Panel */
        .left-panel {
            flex: 0 0 35%;
            display: flex;
            flex-direction: column;
            gap: 1.5rem;
        }

        .panel-card {
            background: white;
            border-radius: 12px;
            box-shadow: 0 2px 8px rgba(0,0,0,0.08);
            overflow: hidden;
            transition: box-shadow 0.3s ease;
        }

        .panel-card:hover {
            box-shadow: 0 4px 12px rgba(0,0,0,0.12);
        }

        .panel-card-header {
            background: var(--light-color);
            padding: 1rem;
            border-bottom: 1px solid var(--border-color);
            font-weight: 600;
            font-size: 0.95rem;
            color: #495057;
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }

        .panel-card-body {
            padding: 1.25rem;
        }

        /* Master Selector */
        #masterSelector {
            font-size: 1rem;
            padding: 0.75rem;
            border: 2px solid var(--border-color);
            border-radius: 8px;
            transition: border-color 0.3s ease;
        }

        #masterSelector:focus {
            border-color: var(--primary-color);
            box-shadow: 0 0 0 3px rgba(13, 110, 253, 0.1);
        }

        /* Progress Section */
        .master-badge {
            display: inline-block;
            background: linear-gradient(135deg, #0d6efd, #0dcaf0);
            color: white;
            padding: 0.5rem 1rem;
            border-radius: 20px;
            font-size: 0.85rem;
            font-weight: 600;
            margin-bottom: 1rem;
        }

        .progress-card {
            background: linear-gradient(135deg, #fff5e6, #fffbf0);
            border: 2px solid #ffc107;
            border-radius: 8px;
            padding: 1rem;
            margin-bottom: 1rem;
        }

        .progress-card-title {
            font-weight: 700;
            color: #333;
            margin-bottom: 0.75rem;
            font-size: 0.95rem;
        }

        .progress-bar-large {
            height: 28px;
            background: #e9ecef;
            border-radius: 6px;
            overflow: hidden;
            margin-bottom: 0.75rem;
        }

        .progress-bar-large .progress-bar {
            font-weight: 600;
            font-size: 0.9rem;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: width 0.5s ease;
        }

        .progress-percentage {
            text-align: center;
            font-weight: 700;
            font-size: 1.1rem;
            color: var(--primary-color);
        }

        .status-message {
            text-align: center;
            font-size: 0.9rem;
            color: #666;
            margin-top: 0.5rem;
        }

        /* Certificate Status List */
        .cert-status-list {
            list-style: none;
            padding: 0;
            margin: 0;
        }

        .cert-status-item {
            display: flex;
            align-items: center;
            gap: 0.75rem;
            padding: 0.75rem;
            border-radius: 6px;
            background: var(--light-color);
            margin-bottom: 0.5rem;
            font-size: 0.9rem;
            transition: background-color 0.2s ease;
        }

        .cert-status-item:hover {
            background: #e9ecef;
        }

        .cert-status-icon {
            font-size: 1.2rem;
            min-width: 1.5rem;
            text-align: center;
        }

        .cert-status-name {
            flex: 1;
            font-weight: 500;
            color: #333;
        }

        .cert-status-dot {
            width: 12px;
            height: 12px;
            border-radius: 50%;
            display: inline-block;
        }

        /* Right Panel */
        .right-panel {
            flex: 1;
            display: flex;
            flex-direction: column;
        }

        .tab-navigation {
            display: flex;
            gap: 0.5rem;
            margin-bottom: 1.5rem;
            border-bottom: 2px solid var(--border-color);
        }

        .tab-button {
            background: none;
            border: none;
            padding: 0.75rem 1.5rem;
            font-weight: 600;
            font-size: 0.95rem;
            color: #666;
            cursor: pointer;
            border-bottom: 3px solid transparent;
            transition: all 0.3s ease;
            margin-bottom: -2px;
        }

        .tab-button:hover {
            color: var(--primary-color);
        }

        .tab-button.active {
            color: var(--primary-color);
            border-bottom-color: var(--primary-color);
        }

        .tab-content {
            display: none;
            flex: 1;
        }

        .tab-content.active {
            display: flex;
            flex-direction: column;
        }

        /* Certificates Tab */
        #certificatesContainer {
            display: flex;
            flex-direction: column;
            gap: 1rem;
            overflow-y: auto;
            flex: 1;
        }

        /* Progress Dashboard */
        .progress-dashboard {
            display: flex;
            flex-direction: column;
            gap: 1rem;
            overflow-y: auto;
            flex: 1;
        }

        .module-progress-table {
            width: 100%;
            border-collapse: collapse;
            background: white;
            border-radius: 8px;
            overflow: hidden;
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        }

        .module-progress-table thead {
            background: var(--light-color);
        }

        .module-progress-table th {
            padding: 0.875rem;
            text-align: left;
            font-weight: 600;
            font-size: 0.85rem;
            color: #495057;
            border-bottom: 2px solid var(--border-color);
        }

        .module-progress-table td {
            padding: 0.875rem;
            border-bottom: 1px solid var(--border-color);
            font-size: 0.9rem;
        }

        .module-progress-table tbody tr:hover {
            background: rgba(13, 110, 253, 0.02);
        }

        .module-name {
            font-weight: 500;
            color: #333;
        }

        .progress-mini-bar {
            width: 100%;
            height: 6px;
            background: #e9ecef;
            border-radius: 3px;
            overflow: hidden;
            display: inline-block;
        }

        .progress-mini-bar .fill {
            height: 100%;
            background: var(--primary-color);
            transition: width 0.3s ease;
        }

        .completion-badge {
            display: inline-block;
            padding: 0.25rem 0.75rem;
            border-radius: 12px;
            font-size: 0.8rem;
            font-weight: 600;
            text-transform: uppercase;
        }

        .completion-badge.complete {
            background: rgba(25, 135, 84, 0.1);
            color: var(--success-color);
        }

        .completion-badge.in-progress {
            background: rgba(255, 193, 7, 0.1);
            color: #856404;
        }

        .completion-badge.not-started {
            background: rgba(108, 117, 125, 0.1);
            color: #6c757d;
        }

        /* Course Selection */
        .course-search {
            margin-bottom: 1rem;
        }

        .course-search input {
            width: 100%;
            padding: 0.75rem;
            border: 2px solid var(--border-color);
            border-radius: 8px;
            font-size: 0.95rem;
        }

        .course-list {
            background: white;
            border-radius: 8px;
            padding: 1rem;
            max-height: 400px;
            overflow-y: auto;
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        }

        .course-item {
            padding: 0.75rem;
            border-radius: 6px;
            background: var(--light-color);
            margin-bottom: 0.5rem;
            cursor: move;
            transition: all 0.2s ease;
            user-select: none;
        }

        .course-item:hover {
            background: #e9ecef;
            transform: translateX(2px);
        }

        .course-item.used {
            opacity: 0.5;
            cursor: not-allowed;
        }

        .course-item-name {
            font-weight: 500;
            color: #333;
            font-size: 0.9rem;
        }

        .course-item-meta {
            font-size: 0.8rem;
            color: #999;
            margin-top: 0.25rem;
        }

        /* Modules Display */
        .modules-accordion {
            display: flex;
            flex-direction: column;
            gap: 0.75rem;
        }

        .module-card {
            background: white;
            border-radius: 8px;
            border: 1px solid var(--border-color);
            overflow: hidden;
            box-shadow: 0 1px 4px rgba(0,0,0,0.05);
        }

        .module-card-header {
            background: var(--light-color);
            padding: 1rem;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: space-between;
            font-weight: 600;
            user-select: none;
            transition: background-color 0.2s ease;
            border-bottom: 2px solid var(--border-color);
        }

        .module-card-header:hover {
            background: #e9ecef;
        }

        .module-card-header.expanded {
            background: #f0f0f0;
        }

        .module-card-title {
            display: flex;
            align-items: center;
            gap: 0.75rem;
            flex: 1;
        }

        .module-card-toggle {
            font-size: 0.8rem;
            color: #666;
            transition: transform 0.2s ease;
        }

        .module-card-toggle.expanded {
            transform: rotate(180deg);
        }

        .module-card-stats {
            font-size: 0.8rem;
            color: #999;
            margin-left: auto;
            white-space: nowrap;
        }

        .module-card-body {
            padding: 1rem;
            display: none;
            flex-direction: column;
            gap: 0.75rem;
        }

        .module-card-body.expanded {
            display: flex;
        }

        .course-check-item {
            display: flex;
            align-items: flex-start;
            gap: 0.75rem;
            padding: 0.75rem;
            background: var(--light-color);
            border-radius: 6px;
            transition: background-color 0.2s ease;
        }

        .course-check-item:hover {
            background: #e9ecef;
        }

        .course-check-item.completed {
            opacity: 0.7;
        }

        .course-check-item input[type="checkbox"] {
            margin-top: 0.25rem;
            cursor: pointer;
            width: 18px;
            height: 18px;
        }

        .course-check-info {
            flex: 1;
        }

        .course-check-name {
            font-weight: 500;
            color: #333;
            font-size: 0.9rem;
        }

        .course-check-credits {
            font-size: 0.8rem;
            color: #999;
            margin-top: 0.2rem;
        }

        /* No Master Selected State */
        .empty-state {
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            padding: 3rem 2rem;
            text-align: center;
            color: #999;
            background: white;
            border-radius: 12px;
            min-height: 400px;
        }

        .empty-state-icon {
            font-size: 3rem;
            margin-bottom: 1rem;
            opacity: 0.3;
        }

        .empty-state-text {
            font-size: 1rem;
            line-height: 1.5;
        }

        /* Responsive */
        @media (max-width: 1200px) {
            .content-wrapper {
                flex-direction: column;
            }

            .left-panel {
                flex: 0 0 auto;
            }

            .right-panel {
                flex: 1;
            }
        }

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

        .tab-content.active {
            animation: fadeIn 0.3s ease;
        }