/* ===================== QUIZ MODERN DESIGN - 2025 ===================== */

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --success-color: #10b981;
    --error-color: #ef4444;
    --warning-color: #f59e0b;
    --bg-light: #f8fafc;
    --bg-white: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --quiz-question-font-size: 22px;
    --quiz-answer-font-size: 16px;
    
    /* Exam specific variables */
    --exam-primary: #2563eb;
    --exam-timer-bg: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
    --exam-result-pass: linear-gradient(135deg, #10b981 0%, #059669 100%);
    --exam-result-fail: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
}

/* ===================== CONTAINER ===================== */
.quiz-container-modern {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
    background: var(--bg-light);
    min-height: auto; /* Loại bỏ min-height: 100vh để không chiếm quá nhiều không gian */
}

/* ===================== HEADER ===================== */
.quiz-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, #3b82f6 100%);
    border-radius: var(--radius-lg);
    padding: 24px 32px;
    margin-top: 24px;
    margin-bottom: 24px;
    box-shadow: var(--shadow-lg);
    color: white;
}

.quiz-header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 24px;
}

.quiz-stats {
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
}

.stat-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 16px;
    font-weight: 500;
    background: rgba(255, 255, 255, 0.2);
    padding: 8px 16px;
    border-radius: var(--radius-md);
    backdrop-filter: blur(10px);
}

.stat-item i {
    font-size: 18px;
}

/* ===================== TIMER CONTAINER ===================== */
.timer-container {
    margin-top: 20px;
}

.progress-container {
    height: 40px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 20px;
    padding: 4px;
    position: relative;
    overflow: hidden;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, #10b981 0%, #059669 100%);
    border-radius: 16px;
    position: absolute;
    top: 0;
    left: 0;
    transition: width 0.3s ease;
    width: 100%;
}

.progress-bar.danger {
    background: linear-gradient(90deg, #ef4444 0%, #dc2626 100%);
}

.timerrh {
    font-size: 16px;
    font-weight: 700;
    text-align: center;
    color: white;
    width: 100%;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 1;
    text-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
}

/* ===================== MAIN WRAPPER ===================== */
.quiz-main-wrapper {
    display: grid;
    grid-template-columns: 320px 1fr;
    gap: 24px;
    align-items: start;
}

/* ===================== SIDEBAR ===================== */
.quiz-sidebar {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: 20px;
    box-shadow: var(--shadow-md);
    height: fit-content;
    position: sticky;
    top: 20px;
    max-height: calc(100vh - 40px);
    overflow-y: auto;
    align-self: start;
}

.sidebar-section {
    margin-bottom: 24px;
}

.sidebar-section:last-child {
    margin-bottom: 0;
}

.sidebar-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.sidebar-title i {
    color: var(--primary-color);
}

.sidebar-header-actions {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

/* ===================== QUESTION NUMBERS GRID ===================== */
.question-numbers-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 8px;
    max-height: 400px;
    overflow-y: auto;
    padding: 4px;
}

.sidebar-submit-wrapper {
    margin-top: 16px;
}

/* ===================== QUIZ MODAL ===================== */
.quiz-modal {
    position: fixed;
    inset: 0;
    z-index: 1050;
}

.quiz-modal-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(15, 23, 42, 0.55);
}

.quiz-modal-dialog {
    position: relative;
    max-width: 420px;
    margin: 0 auto;
    top: 25%;
    background: #ffffff;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}

.quiz-modal-header {
    padding: 14px 18px;
    border-bottom: 1px solid var(--border-color);
}

.quiz-modal-header h4 {
    margin: 0;
    font-size: 16px;
    font-weight: 700;
    color: var(--text-primary);
}

.quiz-modal-body {
    padding: 14px 18px;
    font-size: 14px;
    color: var(--text-primary);
}

.quiz-modal-footer {
    padding: 10px 18px 14px;
    display: flex;
    justify-content: flex-end;
    gap: 8px;
    border-top: 1px solid var(--border-color);
}

.quiz-modal-footer .btn-primary,
.quiz-modal-footer .btn-secondary {
    border-radius: var(--radius-md);
    padding: 8px 14px;
    font-size: 14px;
}

.quiz-modal-footer .btn-secondary {
    background: #e5e7eb;
    color: #111827;
}

.quiz-modal-footer .btn-secondary:hover {
    background: #d1d5db;
}

.question-number-huy {
    width: 100%;
    aspect-ratio: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    background: var(--bg-white);
    color: var(--text-primary);
    font-weight: 600;
    font-size: 14px;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
}

.question-number-huy:hover {
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.question-number-huy.active-huy {
    background: linear-gradient(135deg, #fbbf24 0%, #f59e0b 100%);
    border-color: #f59e0b;
    color: white;
    box-shadow: var(--shadow-md);
}

.question-number-huy.answered {
    background: linear-gradient(135deg, #dbeafe 0%, #bfdbfe 100%);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.question-number-huy.correct-huy {
    background: linear-gradient(135deg, var(--success-color) 0%, #059669 100%);
    border-color: var(--success-color);
    color: white;
}

.question-number-huy.incorrect-huy {
    background: linear-gradient(135deg, var(--error-color) 0%, #dc2626 100%);
    border-color: var(--error-color);
    color: white;
}

/* ===================== SIDEBAR BUTTONS ===================== */
.btn-action-sidebar {
    width: 100%;
    padding: 12px 16px;
    border: none;
    border-radius: var(--radius-md);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin-bottom: 12px;
    text-decoration: none;
}

.btn-action-sidebar:last-child {
    margin-bottom: 0;
}

.btn-primary-sidebar {
    background: linear-gradient(135deg, var(--primary-color) 0%, #3b82f6 100%);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary-sidebar:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-warning-sidebar {
    background: linear-gradient(135deg, var(--warning-color) 0%, #d97706 100%);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-warning-sidebar:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-success-sidebar {
    background: linear-gradient(135deg, var(--success-color) 0%, #059669 100%);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-success-sidebar:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-outline-sidebar {
    background: var(--bg-white);
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-outline-sidebar:hover {
    background: var(--primary-color);
    color: white;
}

/* ===================== EXAM TYPE CARDS ===================== */
.exam-type-cards-grid {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: 32px;
    box-shadow: var(--shadow-md);
    margin-bottom: 24px;
}

.exam-type-title {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 24px;
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
}

.exam-type-title i {
    color: var(--primary-color);
    font-size: 28px;
}

.exam-cards-row {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.exam-type-card {
    background: var(--bg-white);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 24px;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
    position: relative;
    overflow: visible;
}

/* Card Phổ biến - Nổi bật hơn */
.exam-card-pho-bien {
    border: 3px solid #fbbf24;
    box-shadow: 0 4px 16px rgba(251, 191, 36, 0.25);
    background: linear-gradient(135deg, #ffffff 0%, #fffbeb 100%);
}

.exam-card-pho-bien:hover {
    border-color: #f59e0b;
    box-shadow: 0 6px 24px rgba(251, 191, 36, 0.4);
    transform: translateY(-6px);
}

.exam-type-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color) 0%, #3b82f6 100%);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.exam-type-card:hover {
    border-color: var(--primary-color);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.exam-type-card:hover::before {
    transform: scaleX(1);
}

.exam-card-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 16px;
    background: linear-gradient(135deg, var(--primary-color) 0%, #3b82f6 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 28px;
    box-shadow: var(--shadow-md);
}

.exam-card-content {
    text-align: center;
}

.exam-card-title {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 16px;
}

/* Tag Phổ biến - Góc trên bên phải */
.exam-badge-pho-bien {
    position: absolute;
    top: 12px;
    right: 12px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 4px;
    padding: 6px 12px;
    background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
    color: #92400e;
    font-weight: 700;
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    box-shadow: 0 2px 8px rgba(251, 191, 36, 0.3);
    border: 2px solid #fbbf24;
    border-radius: 6px;
    white-space: nowrap;
    z-index: 10;
    animation: pulse-glow 2s ease-in-out infinite;
}

@keyframes pulse-glow {
    0%, 100% {
        box-shadow: 0 2px 8px rgba(251, 191, 36, 0.3);
    }
    50% {
        box-shadow: 0 2px 12px rgba(251, 191, 36, 0.5);
    }
}

/* Tag Nâng hạng - Góc trên bên phải */
.exam-badge-nang-hang {
    position: absolute;
    top: 12px;
    right: 12px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 4px;
    padding: 5px 10px;
    background: #f3f4f6;
    color: #6b7280;
    font-weight: 500;
    font-size: 10px;
    text-transform: uppercase;
    letter-spacing: 0.3px;
    white-space: nowrap;
    z-index: 10;
    border: 1px solid #d1d5db;
    border-radius: 6px;
}

.exam-card-info {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-bottom: 12px;
    flex-wrap: wrap;
}

.exam-info-item {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 14px;
    color: var(--text-secondary);
    font-weight: 500;
}

.exam-info-item i {
    color: var(--primary-color);
    font-size: 16px;
}

.exam-card-description {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 12px;
    margin-bottom: 12px;
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    border: 1px solid #bae6fd;
    border-radius: var(--radius-sm);
    font-size: 13px;
    color: var(--text-primary);
    line-height: 1.5;
    text-align: center;
    font-weight: 500;
}

.exam-card-description i {
    color: var(--primary-color);
    font-size: 14px;
    flex-shrink: 0;
}

.exam-card-pass {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    background: linear-gradient(135deg, #d1fae5 0%, #a7f3d0 100%);
    color: var(--success-color);
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 14px;
    margin-bottom: 12px;
}

.exam-card-pass i {
    font-size: 16px;
}

.exam-badge-diemliet {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    background: linear-gradient(135deg, #fee2e2 0%, #fecaca 100%);
    color: var(--error-color);
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 12px;
}

.exam-badge-diemliet i {
    font-size: 14px;
}

/* ===================== QUIZ CONTENT ===================== */
.quiz-content {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: 32px;
    box-shadow: var(--shadow-md);
}

/* ===================== NAVIGATION ===================== */
.quiz-navigation-top,
.quiz-navigation-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 8px;
    margin-bottom: 12px;
    padding: 12px;
    background: var(--bg-light);
    border-radius: var(--radius-md);
}

.quiz-navigation-bottom {
    margin-top: 12px;
    margin-bottom: 0;
}

.btn-nav {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 10px 16px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.btn-nav:hover:not(:disabled) {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-nav:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-nav i {
    font-size: 14px;
}

.btn-prev {
    background: var(--text-secondary);
}

.btn-prev:hover:not(:disabled) {
    background: #475569;
}

.nav-info {
    flex: 1;
    text-align: center;
}

.question-counter {
    display: block;
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.keyboard-hint {
    font-size: 11px;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 4px;
}

.nav-actions {
    flex: 1;
    display: flex;
    justify-content: center;
}

.btn-action {
    padding: 12px 24px;
    background: var(--warning-color);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 8px;
    box-shadow: var(--shadow-md);
}

.btn-action:hover {
    background: #d97706;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-submit {
    background: linear-gradient(135deg, var(--error-color) 0%, #dc2626 100%);
    padding: 12px 32px;
    font-size: 16px;
}

.btn-submit:hover {
    background: linear-gradient(135deg, #dc2626 0%, #b91c1c 100%);
}

/* ===================== QUESTION CARD ===================== */
.question-card {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    margin-bottom: 12px;
}

.quiz-container-inner {
    position: relative;
}

.question-container {
    margin-bottom: 0;
}

.question-header {
    display: flex;
    gap: 12px;
    margin-bottom: 24px;
    flex-wrap: wrap;
}

.question-badge {
    background: linear-gradient(135deg, var(--primary-color) 0%, #3b82f6 100%);
    color: white;
    padding: 8px 16px;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 14px;
}

.category-badge {
    background: var(--bg-light);
    color: var(--text-primary);
    padding: 8px 16px;
    border-radius: var(--radius-md);
    font-weight: 500;
    font-size: 14px;
    border: 1px solid var(--border-color);
}

.badge-diem-liet {
    background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
    color: white;
    border-color: #dc2626;
    font-weight: 600;
    box-shadow: 0 2px 4px rgba(239, 68, 68, 0.3);
}

.question-text {
    font-size: var(--quiz-question-font-size);
    font-weight: 600;
    color: var(--text-primary);
    line-height: 1.7;
    margin-bottom: 24px;
    letter-spacing: 0.3px;
}

.question-text * {
    font-size: inherit;
    font-weight: inherit;
    color: inherit;
    line-height: inherit;
    letter-spacing: inherit;
}

.question-text h3,
.question-text h5 {
    margin: 0;
    color: var(--text-primary);
}

.question-image-wrapper {
    margin: 24px 0;
    text-align: center;
}

.question-image {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
    display: block;
    margin: 24px auto;
    text-align: center;
}

/* ===================== ANSWERS ===================== */
.answers-container {
    margin-top: 24px;
    font-size: var(--quiz-answer-font-size);
}

.answer-huy {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 16px 20px;
    margin-bottom: 12px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-white);
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    font-size: inherit;
}

.answer-huy:hover {
    border-color: var(--primary-color);
    background: #f0f7ff;
    transform: translateX(4px);
    box-shadow: var(--shadow-sm);
}

.answer-huy input[type="radio"] {
    display: none;
}

.answer-number-huy {
    font-weight: 600;
    font-size: 16px;
    color: var(--primary-color);
    min-width: 24px;
    flex-shrink: 0;
}

.answer-huy.selected {
    border-color: var(--primary-color);
    background: #eff6ff;
}

.answer-huy.correct-huy {
    background: linear-gradient(135deg, #d1fae5 0%, #a7f3d0 100%);
    border-color: var(--success-color);
    color: var(--text-primary);
}

.answer-huy.incorrect-huy {
    background: linear-gradient(135deg, #fee2e2 0%, #fecaca 100%);
    border-color: var(--error-color);
    color: var(--text-primary);
}

.answer-huy.result-correct {
    background: linear-gradient(135deg, #d1fae5 0%, #a7f3d0 100%);
    border-color: var(--success-color);
}

.answer-huy.result-incorrect {
    background: linear-gradient(135deg, #fee2e2 0%, #fecaca 100%);
    border-color: var(--error-color);
}

.answer-huy.correct-huy .answer-number-huy,
.answer-huy.incorrect-huy .answer-number-huy {
    font-size: 18px;
}

/* Legacy support for old classes */
.answer {
    display: block;
    margin-bottom: 10px;
    padding: 10px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    font-size: var(--quiz-answer-font-size);
}

.answer:hover,
.answer.selected {
    border-color: var(--primary-color);
    background: #f0f7ff;
}

.answer.result-correct {
    background: linear-gradient(135deg, #d1fae5 0%, #a7f3d0 100%);
    border-color: var(--success-color);
}

.answer.result-incorrect {
    background: linear-gradient(135deg, #fee2e2 0%, #fecaca 100%);
    border-color: var(--error-color);
}

/* ===================== RESULT BOARD ===================== */
.result-board {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    margin-top: 24px;
    animation: slideDown 0.3s ease-out;
}

.result-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, #3b82f6 100%);
    color: white;
    padding: 24px 32px;
    text-align: center;
}

.result-title {
    font-size: 24px;
    font-weight: 700;
    margin: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
}

.result-title i {
    font-size: 28px;
}

.result-body {
    padding: 32px;
}

.result-message-wrapper {
    text-align: center;
    margin-bottom: 24px;
}

.result-message {
    font-size: 20px;
    font-weight: 600;
    margin: 0;
}

.result-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin-bottom: 24px;
}

.result-stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px;
    background: var(--bg-light);
    border-radius: var(--radius-md);
    text-align: center;
}

.result-stat-label {
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 8px;
    font-weight: 500;
}

.result-stat-value {
    font-size: 32px;
    font-weight: 700;
}

.result-stat-value.score.green,
.result-stat-value.evaluation.green {
    color: var(--success-color);
}

.result-stat-value.score.red,
.result-stat-value.evaluation.red {
    color: var(--error-color);
}

.result-buttons {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    justify-content: center;
    margin-bottom: 32px;
    padding-bottom: 24px;
    border-bottom: 2px solid var(--border-color);
}

.result-buttons button {
    padding: 12px 24px;
    border: none;
    border-radius: var(--radius-md);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-md);
}

.result-buttons .btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, #3b82f6 100%);
    color: white;
}

.result-buttons .btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

/* ===================== TOGGLE MOBILE ===================== */
.question-toggle {
    display: none;
    margin-bottom: 20px;
}

.question-list {
    display: none;
}

.question-list.show {
    display: block;
}

/* ===================== RESPONSIVE ===================== */
@media (max-width: 1024px) {
    .quiz-main-wrapper {
        grid-template-columns: 280px 1fr;
    }
    
    .exam-cards-row {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    :root {
        --quiz-question-font-size: 18px;
        --quiz-answer-font-size: 15px;
    }
    
    .quiz-container-modern {
        padding: 8px;
    }

    .quiz-header {
        padding: 16px;
        margin-top: 12px;
        margin-bottom: 12px;
        border-radius: var(--radius-md);
    }

    .quiz-header-content {
        flex-direction: column;
        align-items: center;
        gap: 16px;
    }

    .quiz-stats {
        gap: 8px;
        width: 100%;
        justify-content: center;
        flex-wrap: wrap;
    }

    .stat-item {
        font-size: 12px;
        padding: 6px 10px;
        flex: 1;
        min-width: calc(33.333% - 6px);
        justify-content: center;
    }

    .timer-container {
        margin-top: 16px;
    }

    .progress-container {
        height: 32px;
    }

    .timerrh {
        font-size: 14px;
    }

    .quiz-main-wrapper {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .quiz-sidebar {
        position: static;
        max-height: none;
        order: 2;
        padding: 16px;
        border-radius: var(--radius-md);
    }

    .question-toggle {
        display: block;
        order: 1;
    }

    .exam-type-cards-grid {
        padding: 20px;
        order: 0;
    }

    .exam-type-title {
        font-size: 20px;
        margin-bottom: 20px;
    }

    .exam-cards-row {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .exam-card-icon {
        width: 56px;
        height: 56px;
        font-size: 24px;
    }

    .exam-card-title {
        font-size: 20px;
    }

    .quiz-content {
        order: 1;
        padding: 16px;
        border-radius: var(--radius-md);
    }

    .quiz-navigation-top,
    .quiz-navigation-bottom {
        flex-direction: row;
        gap: 8px;
        padding: 12px;
        margin-bottom: 16px;
    }

    .quiz-navigation-bottom {
        margin-top: 16px;
        margin-bottom: 0;
    }

    .btn-nav {
        flex: 1;
        padding: 10px 16px;
        font-size: 14px;
        min-width: 0;
    }

    .btn-nav span {
        display: none;
    }

    .btn-nav i {
        margin: 0;
    }

    .nav-info {
        display: none;
    }

    .nav-actions {
        flex: 1;
    }

    .btn-submit {
        width: 100%;
        padding: 14px;
    }

    .question-card {
        padding: 16px;
        border-radius: var(--radius-md);
    }

    .question-header {
        margin-bottom: 16px;
        gap: 8px;
    }

    .question-badge,
    .category-badge {
        padding: 6px 12px;
        font-size: 12px;
    }

    .question-text {
        line-height: 1.6;
        margin-bottom: 16px;
        letter-spacing: 0.2px;
    }

    .answer-huy {
        padding: 12px 14px;
        margin-bottom: 10px;
        border-radius: var(--radius-sm);
    }

    .answer-number-huy {
        font-size: 14px;
        min-width: 20px;
    }

    .result-board {
        margin-top: 16px;
    }

    .result-header {
        padding: 20px;
    }

    .result-title {
        font-size: 20px;
    }

    .result-body {
        padding: 20px;
    }

    .result-stats {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .result-stat-value {
        font-size: 28px;
    }

    .result-buttons {
        flex-direction: column;
    }

    .result-buttons button {
        width: 100%;
    }
}

@media (max-width: 480px) {
    :root {
        --quiz-question-font-size: 17px;
        --quiz-answer-font-size: 14px;
    }
    
    .quiz-container-modern {
        padding: 6px;
    }

    .quiz-header {
        padding: 12px;
        margin-top: 12px;
        margin-bottom: 12px;
    }

    .quiz-header-content {
        gap: 12px;
    }

    .quiz-stats {
        gap: 6px;
    }

    .stat-item {
        font-size: 11px;
        padding: 5px 8px;
        min-width: calc(33.333% - 4px);
    }

    .progress-container {
        height: 28px;
    }

    .timerrh {
        font-size: 12px;
    }

    .quiz-sidebar {
        padding: 12px;
    }

    .sidebar-section {
        margin-bottom: 16px;
    }

    .sidebar-title {
        font-size: 14px;
        margin-bottom: 8px;
    }

    .question-numbers-grid {
        grid-template-columns: repeat(4, 1fr);
        gap: 6px;
        max-height: 300px;
    }

    .question-number-huy {
        font-size: 12px;
    }

    .btn-action-sidebar {
        padding: 10px 12px;
        font-size: 13px;
    }

    .exam-type-cards-grid {
        padding: 16px;
    }

    .exam-type-title {
        font-size: 18px;
        margin-bottom: 16px;
    }

    .exam-card-icon {
        width: 48px;
        height: 48px;
        font-size: 20px;
    }

    .exam-card-title {
        font-size: 18px;
    }

    .exam-card-info {
        gap: 12px;
    }

    .exam-info-item {
        font-size: 12px;
    }

    .quiz-content {
        padding: 12px;
    }

    .quiz-navigation-top,
    .quiz-navigation-bottom {
        padding: 10px;
        gap: 6px;
    }

    .btn-nav {
        padding: 8px 12px;
        font-size: 13px;
        min-height: 44px;
    }

    .question-card {
        padding: 12px;
    }

    .question-header {
        margin-bottom: 12px;
    }

    .question-badge,
    .category-badge {
        padding: 5px 10px;
        font-size: 11px;
    }

    .question-text {
        line-height: 1.6;
        margin-bottom: 12px;
        letter-spacing: 0.2px;
    }

    .answer-huy {
        padding: 10px 12px;
        margin-bottom: 8px;
    }

    .answer-number-huy {
        font-size: 13px;
        min-width: 18px;
    }

    .result-header {
        padding: 16px;
    }

    .result-title {
        font-size: 18px;
    }

    .result-body {
        padding: 16px;
    }

    .result-stat-value {
        font-size: 24px;
    }
}

/* ===================== SCROLLBAR STYLING ===================== */
.question-numbers-grid::-webkit-scrollbar,
.quiz-sidebar::-webkit-scrollbar {
    width: 8px;
}

.question-numbers-grid::-webkit-scrollbar-track,
.quiz-sidebar::-webkit-scrollbar-track {
    background: var(--bg-light);
    border-radius: 4px;
}

.question-numbers-grid::-webkit-scrollbar-thumb,
.quiz-sidebar::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

.question-numbers-grid::-webkit-scrollbar-thumb:hover,
.quiz-sidebar::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

/* ===================== EXAM SELECTION SECTION ===================== */
.exam-selection-section {
    margin-bottom: 24px;
}

.exam-number-selection {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: 32px;
    box-shadow: var(--shadow-md);
}

.exam-number-selection-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 24px;
    flex-wrap: wrap;
}

.btn-back-exam-type {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
    background: var(--bg-light);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.btn-back-exam-type:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.exam-number-title {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 12px;
    flex: 1;
}

.exam-number-title i {
    color: var(--primary-color);
}

.exam-numbers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 16px;
}

.exam-number-card {
    background: var(--bg-white);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 20px;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.exam-number-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color) 0%, #3b82f6 100%);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.exam-number-card:hover {
    border-color: var(--primary-color);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.exam-number-card:hover::before {
    transform: scaleX(1);
}

.exam-number-icon {
    width: 56px;
    height: 56px;
    margin: 0 auto 12px;
    background: linear-gradient(135deg, var(--primary-color) 0%, #3b82f6 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 24px;
    box-shadow: var(--shadow-md);
}

.exam-number-content {
    text-align: center;
}

.exam-number-title {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.exam-number-info {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-bottom: 8px;
    flex-wrap: wrap;
}

.exam-number-status {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 12px;
    margin-top: 8px;
}

.exam-number-status.status-not-done {
    background: var(--bg-light);
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
}

.exam-number-status.status-passed {
    background: linear-gradient(135deg, #d1fae5 0%, #a7f3d0 100%);
    color: var(--success-color);
    border: 1px solid var(--success-color);
}

.exam-number-status.status-failed {
    background: linear-gradient(135deg, #fee2e2 0%, #fecaca 100%);
    color: var(--error-color);
    border: 1px solid var(--error-color);
}

.exam-number-card.status-passed {
    border-color: var(--success-color);
    background: linear-gradient(135deg, #f0fdf4 0%, #dcfce7 100%);
}

.exam-number-card.status-failed {
    border-color: var(--error-color);
    background: linear-gradient(135deg, #fef2f2 0%, #fee2e2 100%);
}

.exam-number-card.exam-random {
    border: 2px dashed var(--primary-color);
}

.exam-number-card.exam-random:hover {
    border-color: var(--primary-color);
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
}

/* ===================== EXAM RESULT SECTION ===================== */
.exam-result-section {
    margin-bottom: 24px;
}

.result-overview {
    margin-bottom: 32px;
}

.result-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-bottom: 24px;
}

.result-stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px;
    background: var(--bg-light);
    border-radius: var(--radius-md);
    text-align: center;
}

.result-stat-value.time-spent,
.result-stat-value.correct-count,
.result-stat-value.wrong-count {
    font-size: 24px;
    font-weight: 700;
}

.result-stat-value.correct-count {
    color: var(--success-color);
}

.result-stat-value.wrong-count {
    color: var(--error-color);
}

/* Compact result overview layout */
.result-overview-compact {
    margin-bottom: 16px;
}

.result-main-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    flex-wrap: wrap;
}

.result-main-score {
    display: flex;
    flex-direction: column;
    padding: 12px 16px;
    border-radius: var(--radius-md);
    background: var(--bg-light);
    min-width: 190px;
}

.result-main-label {
    font-size: 13px;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 4px;
}

/* legacy: result-main-values / score-value / evaluation (không còn dùng) */

.result-main-extra {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.result-main-extra-item {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 6px 10px;
    border-radius: 999px;
    background: var(--bg-light);
    font-size: 13px;
}

.result-main-extra-label {
    color: var(--text-secondary);
}

.result-main-extra-value {
    font-weight: 600;
}

.result-message-compact {
    margin-top: 10px;
    margin-bottom: 0;
}

/* Quiz header khi nằm trong khu vực KẾT QUẢ THI (gọn hơn, ít chiếm diện tích) */
.exam-result-section .quiz-header {
    background: transparent;
    border-radius: 0;
    padding: 12px 24px 4px;
    margin-top: 8px;
    margin-bottom: 4px;
    box-shadow: none;
    color: var(--text-primary);
}

.exam-result-section .quiz-header-content {
    gap: 12px;
}

.exam-result-section .quiz-stats {
    gap: 12px;
    flex-wrap: wrap;
}

.exam-result-section .stat-item {
    font-size: 13px;
}

.exam-result-section #timerDisplay {
    font-weight: 600;
}

@media (max-width: 768px) {
    .result-main-row {
        flex-direction: column;
        align-items: stretch;
    }

    .result-main-extra {
        justify-content: flex-start;
    }
}

.result-stat-value.diem-liet-status.green {
    color: var(--success-color);
}

.result-stat-value.diem-liet-status.red {
    color: var(--error-color);
}

/* ===================== WRONG QUESTIONS SECTION ===================== */
.wrong-questions-section {
    margin-top: 32px;
    padding-top: 32px;
    border-top: 2px solid var(--border-color);
}

.wrong-questions-title {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.wrong-questions-title i {
    color: var(--error-color);
}

.wrong-questions-list {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.wrong-question-item {
    background: var(--bg-light);
    border-radius: var(--radius-md);
    padding: 24px;
    border: 2px solid var(--border-color);
    transition: var(--transition);
}

.wrong-question-item:hover {
    border-color: var(--error-color);
    box-shadow: var(--shadow-md);
}

.wrong-question-header {
    margin-bottom: 16px;
}

.wrong-question-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

.diem-liet-badge {
    display: inline-block;
    padding: 4px 8px;
    background: linear-gradient(135deg, #fee2e2 0%, #fecaca 100%);
    color: var(--error-color);
    border-radius: var(--radius-sm);
    font-size: 12px;
    font-weight: 600;
    margin-left: 8px;
}

.wrong-question-content {
    margin-top: 16px;
}

.wrong-question-text {
    font-size: 16px;
    font-weight: 500;
    color: var(--text-primary);
    line-height: 1.6;
    margin-bottom: 16px;
}

.wrong-question-image {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-md);
    margin: 16px 0;
    box-shadow: var(--shadow-sm);
}

.wrong-answers-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin: 16px 0;
}

.wrong-answer-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-white);
    transition: var(--transition);
}

.wrong-answer-item.correct-answer {
    background: linear-gradient(135deg, #d1fae5 0%, #a7f3d0 100%);
    border-color: var(--success-color);
}

.wrong-answer-item.wrong-answer {
    background: linear-gradient(135deg, #fee2e2 0%, #fecaca 100%);
    border-color: var(--error-color);
}

.answer-number {
    font-weight: 600;
    font-size: 16px;
    color: var(--primary-color);
    min-width: 24px;
    flex-shrink: 0;
}

.answer-text {
    flex: 1;
    font-size: 15px;
    line-height: 1.5;
}

.correct-icon {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 8px;
    background: var(--success-color);
    color: white;
    border-radius: var(--radius-sm);
    font-size: 12px;
    font-weight: 600;
    margin-left: 8px;
}

.wrong-icon {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 8px;
    background: var(--error-color);
    color: white;
    border-radius: var(--radius-sm);
    font-size: 12px;
    font-weight: 600;
    margin-left: 8px;
}

.wrong-question-explanation {
    margin-top: 16px;
    padding: 16px;
    background: #f0f9ff;
    border-left: 4px solid var(--primary-color);
    border-radius: var(--radius-sm);
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-primary);
}

.wrong-question-explanation strong {
    color: var(--primary-color);
}

/* ===================== EXAM HISTORY SECTION ===================== */
.exam-history-section {
    margin-top: 48px;
    padding-top: 32px;
    border-top: 3px solid var(--border-color);
}

.history-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    flex-wrap: wrap;
    gap: 16px;
}

.history-title {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 12px;
    margin: 0;
}

.history-title i {
    color: var(--primary-color);
}

.btn-clear-history {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
    background: var(--error-color);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.btn-clear-history:hover {
    background: #dc2626;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.history-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.history-empty {
    text-align: center;
    padding: 48px 24px;
    color: var(--text-secondary);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.history-empty i {
    font-size: 48px;
    color: var(--border-color);
    margin-bottom: 16px;
    display: block;
}

.history-empty p {
    font-size: 16px;
    margin: 0;
    text-align: center;
}

.history-item {
    background: var(--bg-white);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 20px;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.history-item:hover {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.history-item-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
    flex-wrap: wrap;
    gap: 12px;
}

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

.history-exam-type {
    font-size: 18px;
    font-weight: 700;
    color: var(--primary-color);
}

.history-exam-number {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    padding: 4px 12px;
    background: var(--bg-light);
    border-radius: var(--radius-sm);
}

.history-status {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 600;
}

.history-status.passed {
    background: linear-gradient(135deg, #d1fae5 0%, #a7f3d0 100%);
    color: var(--success-color);
}

.history-status.failed {
    background: linear-gradient(135deg, #fee2e2 0%, #fecaca 100%);
    color: var(--error-color);
}

.history-item-date {
    font-size: 14px;
    color: var(--text-secondary);
}

.history-item-body {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 12px;
    margin-bottom: 16px;
}

.history-stat {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.history-stat-label {
    font-size: 12px;
    color: var(--text-secondary);
    font-weight: 500;
}

.history-stat-value {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-primary);
}

.history-stat-value.green {
    color: var(--success-color);
}

.history-stat-value.red {
    color: var(--error-color);
}

.history-item-actions {
    display: flex;
    justify-content: flex-end;
    padding-top: 16px;
    border-top: 1px solid var(--border-color);
}

.btn-view-detail {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.btn-view-detail:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* ===================== RESPONSIVE UPDATES ===================== */
@media (max-width: 768px) {
    .exam-numbers-grid {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
        gap: 12px;
    }
    
    .exam-number-card {
        padding: 16px;
    }
    
    .exam-number-icon {
        width: 48px;
        height: 48px;
        font-size: 20px;
    }
    
    .result-stats {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .wrong-question-item {
        padding: 16px;
    }
    
    .history-item-header {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .history-item-body {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .exam-numbers-grid {
        grid-template-columns: 1fr;
    }
    
    .result-stats {
        grid-template-columns: 1fr;
    }
    
    .history-item-body {
        grid-template-columns: 1fr;
    }
}