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

        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background-color: #f8fafc;
            color: #1e293b;
            line-height: 1.6;
        }

        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 1rem;
        }

        .header {
            background: white;
            border-bottom: 1px solid #e2e8f0;
            padding: 1.5rem 0;
            box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
        }

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

        .logo {
            width: 48px;
            height: 48px;
            background: #3b82f6;
            border-radius: 8px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 24px;
        }

        .header-text h1 {
            font-size: 2rem;
            font-weight: bold;
            color: #1e293b;
            margin-bottom: 0.25rem;
        }

        .header-text p {
            color: #64748b;
        }

        .main {
            padding: 2rem 0;
        }

        .page {
            display: none;
        }

        .page.active {
            display: block;
        }

        .intro-section {
            text-align: center;
            margin-bottom: 2rem;
        }

        .intro-section h2 {
            font-size: 1.75rem;
            font-weight: 600;
            margin-bottom: 1rem;
        }

        .intro-section .subtitle {
            color: #64748b;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 0.5rem;
        }

        .exam-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
            gap: 1rem;
            max-width: 800px;
            margin: 0 auto 3rem;
        }

        .exam-card {
            background: white;
            border: 1px solid #e2e8f0;
            border-radius: 8px;
            padding: 1.5rem;
            text-align: center;
            cursor: pointer;
            transition: all 0.2s;
            box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
        }

        .exam-card:hover {
            transform: translateY(-2px);
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
            border-color: #3b82f6;
        }

        .exam-card .exam-icon {
            font-size: 24px;
            margin-bottom: 0.5rem;
        }

        .exam-card .exam-label {
            font-weight: 600;
            margin-bottom: 0.25rem;
        }

        .exam-card .exam-id {
            font-size: 0.75rem;
            color: #64748b;
        }

        .language-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 1rem;
            margin-bottom: 2rem;
        }

        .language-card {
            background: white;
            border: 2px solid #e2e8f0;
            border-radius: 8px;
            padding: 1rem;
            text-align: center;
            cursor: pointer;
            transition: all 0.2s;
        }

        .language-card:hover {
            border-color: #3b82f6;
            background: #f8fafc;
        }

        .language-card.selected {
            border-color: #3b82f6;
            background: #eff6ff;
        }

        .language-card .flag {
            font-size: 2rem;
            margin-bottom: 0.5rem;
        }

        .language-card .name {
            font-weight: 600;
            margin-bottom: 0.25rem;
        }

        .language-card .native-name {
            font-size: 0.875rem;
            color: #64748b;
        }

        .btn {
            background: #3b82f6;
            color: white;
            border: none;
            padding: 0.75rem 1.5rem;
            border-radius: 6px;
            font-weight: 600;
            cursor: pointer;
            transition: background 0.2s;
            display: inline-flex;
            align-items: center;
            gap: 0.5rem;
        }

        .btn:hover {
            background: #2563eb;
        }

        .btn:disabled {
            background: #94a3b8;
            cursor: not-allowed;
        }

        .btn-outline {
            background: transparent;
            color: #3b82f6;
            border: 1px solid #3b82f6;
        }

        .btn-outline:hover {
            background: #3b82f6;
            color: white;
        }

        .test-header {
            background: white;
            border-bottom: 1px solid #e2e8f0;
            padding: 1rem 0;
            position: sticky;
            top: 0;
            z-index: 10;
        }

        .test-header-content {
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
            gap: 1rem;
        }

        .test-info {
            display: flex;
            align-items: center;
            gap: 1rem;
        }

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

        .progress-section {
            margin-top: 1rem;
        }

        .progress-info {
            display: flex;
            justify-content: space-between;
            margin-bottom: 0.5rem;
            font-size: 0.875rem;
            color: #64748b;
        }

        .progress-bar {
            width: 100%;
            height: 8px;
            background: #e2e8f0;
            border-radius: 4px;
            overflow: hidden;
        }

        .progress-fill {
            height: 100%;
            background: #3b82f6;
            transition: width 0.3s;
        }

        .question-container {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 2rem;
            margin-bottom: 2rem;
        }

        @media (max-width: 768px) {
            .question-container {
                grid-template-columns: 1fr;
            }
        }

        .question-panel {
            background: white;
            border: 1px solid #e2e8f0;
            border-radius: 8px;
            padding: 1.5rem;
        }

        .panel-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 1rem;
        }

        .badge {
            background: #f1f5f9;
            color: #475569;
            padding: 0.25rem 0.75rem;
            border-radius: 4px;
            font-size: 0.875rem;
            font-weight: 600;
        }

        .question-text {
            font-size: 1.125rem;
            font-weight: 500;
            margin-bottom: 1.5rem;
        }

        .options {
            display: flex;
            flex-direction: column;
            gap: 0.75rem;
        }

        .option {
            padding: 1rem;
            border: 1px solid #e2e8f0;
            border-radius: 6px;
            cursor: pointer;
            transition: all 0.2s;
            background: white;
        }

        .option:hover {
            background: #f8fafc;
            border-color: #3b82f6;
        }

        .option.selected {
            background: #3b82f6;
            color: white;
            border-color: #3b82f6;
        }

        .option.correct {
            background: #22c55e;
            color: white;
            border-color: #22c55e;
        }

        .option.incorrect {
            background: #ef4444;
            color: white;
            border-color: #ef4444;
        }

        .feedback {
            background: white;
            border: 1px solid #e2e8f0;
            border-radius: 8px;
            padding: 1.5rem;
            margin-top: 1.5rem;
        }

        .feedback.correct-feedback {
            background: #f0fdf4;
            border-color: #22c55e;
        }

        .feedback.incorrect-feedback {
            background: #fef2f2;
            border-color: #ef4444;
        }

        .feedback-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 1rem;
        }

        .feedback-icon {
            display: flex;
            align-items: center;
            gap: 0.5rem;
            font-weight: 600;
        }

        .explanation-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 1rem;
            padding-top: 1rem;
            border-top: 1px solid #e2e8f0;
        }

        @media (max-width: 768px) {
            .explanation-grid {
                grid-template-columns: 1fr;
            }
        }

        .explanation-section h4 {
            margin-bottom: 0.5rem;
        }

        .explanation-text {
            font-size: 0.875rem;
            color: #64748b;
            line-height: 1.5;
        }

        .results-card {
            background: white;
            border: 1px solid #e2e8f0;
            border-radius: 8px;
            padding: 2rem;
            text-align: center;
            max-width: 600px;
            margin: 0 auto;
        }

        .result-icon {
            width: 80px;
            height: 80px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1.5rem;
            font-size: 2.5rem;
        }

        .result-icon.passed {
            background: #22c55e;
            color: white;
        }

        .result-icon.failed {
            background: #ef4444;
            color: white;
        }

        .result-title {
            font-size: 2rem;
            font-weight: bold;
            margin-bottom: 0.5rem;
        }

        .result-subtitle {
            color: #64748b;
            margin-bottom: 2rem;
        }

        .stats-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 1.5rem;
            margin-bottom: 2rem;
        }

        .stat {
            text-align: center;
        }

        .stat-value {
            font-size: 2rem;
            font-weight: bold;
            margin-bottom: 0.5rem;
        }

        .stat-label {
            font-size: 0.875rem;
            color: #64748b;
        }

        .back-btn {
            background: transparent;
            color: #64748b;
            border: 1px solid #e2e8f0;
            padding: 0.5rem 1rem;
            border-radius: 6px;
            cursor: pointer;
            transition: all 0.2s;
            display: inline-flex;
            align-items: center;
            gap: 0.5rem;
        }

        .back-btn:hover {
            background: #f8fafc;
            color: #3b82f6;
        }

        .timer {
            display: flex;
            align-items: center;
            gap: 0.5rem;
            font-size: 0.875rem;
            color: #64748b;
        }

        .pause-overlay {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: rgba(0, 0, 0, 0.5);
            display: flex;
            align-items: center;
            justify-content: center;
            z-index: 50;
        }

        .pause-card {
            background: white;
            border-radius: 8px;
            padding: 2rem;
            text-align: center;
            max-width: 400px;
        }

        .hide {
            display: none !important;
        }