:root {
            --primary: #4f46e5;
            --primary-light: #eef2ff;
            --primary-hover: #4338ca;
            --success: #10b981;
            --success-bg: #ecfdf5;
            --danger: #ef4444;
            --danger-bg: #fef2f2;
            --dark: #0f172a;
            --text-main: #1e293b;
            --text-muted: #64748b;
            --card-bg: #ffffff;
            --page-bg: #f8fafc;
            --border: #e2e8f0;
            --radius-xl: 20px;
            --radius-md: 12px;
            --shadow-subtle: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
            --shadow-elevated: 0 20px 25px -5px rgba(15, 23, 42, 0.08), 0 8px 10px -6px rgba(15, 23, 42, 0.04);
        }

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

        body {
            font-family: 'Plus Jakarta Sans', sans-serif;
            background: linear-gradient(135deg, #f0f4ff 0%, #f8fafc 50%, #e0f2fe 100%);
            color: var(--text-main);
            min-height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
            padding: 20px;
        }

        .quiz-wrapper {
            width: 100%;
            max-width: 860px;
            background: var(--card-bg);
            border-radius: var(--radius-xl);
            box-shadow: var(--shadow-elevated);
            border: 1px solid rgba(226, 232, 240, 0.8);
            overflow: hidden;
            position: relative;
        }

        /* Top Status Bar */
        .top-bar {
            background: #ffffff;
            padding: 20px 28px;
            border-bottom: 1px solid var(--border);
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
            gap: 16px;
        }

        .quiz-title-wrap {
            display: flex;
            align-items: center;
            gap: 12px;
        }

        .quiz-icon {
            width: 44px;
            height: 44px;
            background: #e6fcf5;
            color: #0ca678;
            border-radius: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.3rem;
        }

        .quiz-title-wrap h1 {
            font-size: 1.15rem;
            font-weight: 700;
            color: var(--dark);
            letter-spacing: -0.3px;
        }

        .quiz-title-wrap p {
            font-size: 0.8rem;
            color: var(--text-muted);
            font-weight: 500;
        }

        .stat-badges {
            display: flex;
            align-items: center;
            gap: 10px;
            flex-wrap: wrap;
        }

        .badge {
            padding: 6px 14px;
            border-radius: 50px;
            font-size: 0.85rem;
            font-weight: 600;
            display: inline-flex;
            align-items: center;
            gap: 6px;
        }

        .badge-score {
            background: var(--success-bg);
            color: var(--success);
            border: 1px solid #a7f3d0;
        }

        .badge-wrong {
            background: var(--danger-bg);
            color: var(--danger);
            border: 1px solid #fecaca;
        }

        /* Progress Bar */
        .progress-track {
            width: 100%;
            height: 6px;
            background: #e2e8f0;
            position: relative;
        }

        .progress-bar {
            height: 100%;
            width: 0%;
            background: linear-gradient(90deg, var(--primary) 0%, #06b6d4 100%);
            transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1);
        }

        /* Start / Confirmation Screen */
        .start-screen {
            padding: 48px 36px;
            text-align: center;
            animation: fadeIn 0.4s ease;
        }

        .start-icon {
            width: 80px;
            height: 80px;
            background: #e6fcf5;
            color: #0ca678;
            border-radius: 50%;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            font-size: 2.2rem;
            margin-bottom: 20px;
            box-shadow: 0 8px 16px rgba(12, 166, 120, 0.15);
        }

        .start-screen h2 {
            font-size: 1.75rem;
            font-weight: 800;
            color: var(--dark);
            margin-bottom: 8px;
        }

        .exam-subtitle {
            font-size: 0.95rem;
            color: var(--text-muted);
            font-weight: 600;
            margin-bottom: 26px;
        }

        .exam-info-card {
            background: #f8fafc;
            border: 1px solid var(--border);
            border-radius: var(--radius-md);
            padding: 20px 24px;
            margin: 0 auto 32px;
            max-width: 520px;
            text-align: left;
        }

        .exam-info-card h3 {
            font-size: 0.95rem;
            font-weight: 700;
            color: var(--dark);
            margin-bottom: 12px;
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .exam-instructions {
            list-style: none;
            display: flex;
            flex-direction: column;
            gap: 10px;
            font-size: 0.9rem;
            color: var(--text-main);
        }

        .exam-instructions li {
            display: flex;
            align-items: flex-start;
            gap: 10px;
            line-height: 1.4;
        }

        .exam-instructions i {
            color: var(--primary);
            margin-top: 2px;
            flex-shrink: 0;
        }

        /* Card Content Area */
        .card-body {
            padding: 32px 36px;
        }

        .question-meta {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 14px;
        }

        .question-tag {
            font-size: 0.8rem;
            font-weight: 700;
            text-transform: uppercase;
            letter-spacing: 0.8px;
            color: var(--primary);
            background: var(--primary-light);
            padding: 4px 12px;
            border-radius: 6px;
        }

        .progress-percent {
            font-size: 0.85rem;
            font-weight: 600;
            color: var(--text-muted);
        }

        .question-text {
            font-size: 1.25rem;
            font-weight: 700;
            color: var(--dark);
            line-height: 1.5;
            margin-bottom: 24px;
            animation: fadeIn 0.3s ease;
        }

        /* Interactive Option Cards */
        .options-list {
            display: flex;
            flex-direction: column;
            gap: 12px;
            list-style: none;
        }

        .option-item {
            background: #ffffff;
            border: 2px solid var(--border);
            border-radius: var(--radius-md);
            padding: 14px 18px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            cursor: pointer;
            transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
            position: relative;
            user-select: none;
        }

        .option-item:hover:not(.disabled) {
            border-color: var(--primary);
            background: #f8faff;
            transform: translateY(-2px);
            box-shadow: var(--shadow-subtle);
        }

        .option-left {
            display: flex;
            align-items: center;
            gap: 14px;
        }

        .opt-letter {
            width: 34px;
            height: 34px;
            border-radius: 8px;
            background: #f1f5f9;
            color: #475569;
            font-weight: 700;
            font-size: 0.9rem;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: all 0.2s;
            flex-shrink: 0;
        }

        .option-item:hover:not(.disabled) .opt-letter {
            background: var(--primary);
            color: #ffffff;
        }

        .opt-text {
            font-size: 1rem;
            font-weight: 500;
            color: var(--text-main);
            line-height: 1.4;
        }

        .opt-icon {
            font-size: 1.2rem;
            opacity: 0;
            transform: scale(0.5);
            transition: all 0.2s ease;
        }

        /* Success & Failure States */
        .option-item.correct {
            border-color: var(--success) !important;
            background: var(--success-bg) !important;
            box-shadow: 0 4px 12px rgba(16, 185, 129, 0.15);
        }

        .option-item.correct .opt-letter {
            background: var(--success);
            color: #ffffff;
        }

        .option-item.correct .opt-icon {
            opacity: 1;
            transform: scale(1);
            color: var(--success);
        }

        .option-item.incorrect {
            border-color: var(--danger) !important;
            background: var(--danger-bg) !important;
            animation: shake 0.35s ease;
        }

        .option-item.incorrect .opt-letter {
            background: var(--danger);
            color: #ffffff;
        }

        .option-item.incorrect .opt-icon {
            opacity: 1;
            transform: scale(1);
            color: var(--danger);
        }

        .disabled {
            cursor: not-allowed;
            pointer-events: none;
        }

        /* Instant Feedback Pill */
        .feedback-box {
            margin-top: 18px;
            padding: 12px 18px;
            border-radius: var(--radius-md);
            font-size: 0.92rem;
            font-weight: 600;
            display: none;
            align-items: center;
            gap: 10px;
            animation: slideUp 0.3s ease;
        }

        .feedback-box.correct {
            display: flex;
            background: var(--success-bg);
            color: #065f46;
            border: 1px solid #a7f3d0;
        }

        .feedback-box.incorrect {
            display: flex;
            background: var(--danger-bg);
            color: #991b1b;
            border: 1px solid #fecaca;
        }

        /* Bottom Controls */
        .card-footer {
            background: #fafbfc;
            padding: 20px 36px;
            border-top: 1px solid var(--border);
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .sound-toggle {
            background: none;
            border: none;
            color: var(--text-muted);
            cursor: pointer;
            font-size: 1.1rem;
            padding: 8px;
            border-radius: 8px;
            transition: all 0.2s;
        }

        .sound-toggle:hover {
            color: var(--primary);
            background: var(--primary-light);
        }

        .btn-action {
            background: var(--primary);
            color: #ffffff;
            border: none;
            padding: 12px 28px;
            border-radius: var(--radius-md);
            font-weight: 700;
            font-size: 0.95rem;
            cursor: pointer;
            display: inline-flex;
            align-items: center;
            gap: 8px;
            box-shadow: 0 4px 12px rgba(79, 70, 229, 0.25);
            transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
        }

        .btn-action:hover:not(:disabled) {
            background: var(--primary-hover);
            transform: translateY(-2px);
            box-shadow: 0 8px 16px rgba(79, 70, 229, 0.35);
        }

        .btn-action:disabled {
            opacity: 0.45;
            cursor: not-allowed;
            transform: none;
            box-shadow: none;
        }

        /* Results Screen */
        .result-screen {
            display: none;
            padding: 48px 36px;
            text-align: center;
            animation: fadeIn 0.4s ease;
        }

        .trophy-badge {
            width: 80px;
            height: 80px;
            background: #fef3c7;
            color: #f59e0b;
            border-radius: 50%;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            font-size: 2.5rem;
            margin-bottom: 18px;
            box-shadow: 0 8px 16px rgba(245, 158, 11, 0.2);
        }

        .result-screen h2 {
            font-size: 1.8rem;
            font-weight: 800;
            color: var(--dark);
            margin-bottom: 6px;
        }

        .result-desc {
            color: var(--text-muted);
            font-size: 0.95rem;
            margin-bottom: 30px;
        }

        .stats-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 16px;
            margin-bottom: 36px;
        }

        .stat-card {
            background: #f8fafc;
            border: 1px solid var(--border);
            border-radius: var(--radius-md);
            padding: 18px 12px;
        }

        .stat-card .val {
            font-size: 1.8rem;
            font-weight: 800;
            color: var(--dark);
            line-height: 1.2;
        }

        .stat-card .lbl {
            font-size: 0.78rem;
            font-weight: 600;
            color: var(--text-muted);
            text-transform: uppercase;
            margin-top: 4px;
            letter-spacing: 0.5px;
        }

        /* Keyframe Animations */
        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(6px); }
            to { opacity: 1; transform: translateY(0); }
        }

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

        @keyframes shake {
            0%, 100% { transform: translateX(0); }
            20%, 60% { transform: translateX(-6px); }
            40%, 80% { transform: translateX(6px); }
        }

        /* Responsive Adjustments */
        @media (max-width: 640px) {
            body { padding: 10px; }
            .start-screen { padding: 32px 20px; }
            .card-body { padding: 24px 20px; }
            .card-footer { padding: 16px 20px; }
            .question-text { font-size: 1.1rem; }
            .stats-grid { grid-template-columns: 1fr; }
        }