:root {
    /* AWS Color Palette */
    --aws-orange: #FF9900;
    --aws-orange-dark: #EC7211;
    --aws-orange-light: #FFB84D;
    --aws-dark-blue: #232F3E;
    --aws-dark-blue-light: #37475A;
    --aws-squid-ink: #161E2D;

    /* Semantic Colors */
    --color-primary: var(--aws-orange);
    --color-primary-hover: var(--aws-orange-dark);
    --color-primary-light: var(--aws-orange-light);
    --color-dark: var(--aws-dark-blue);
    --color-dark-light: var(--aws-dark-blue-light);
    --color-background: #0F1419;
    --color-surface: #1A1F2E;
    --color-surface-light: #252B3B;

    /* Status Colors */
    --color-success: #2ECC71;
    --color-error: #E74C3C;
    --color-warning: #F39C12;
    --color-info: #3498DB;

    /* Text Colors */
    --color-text-primary: #FFFFFF;
    --color-text-secondary: #B0B8C4;
    --color-text-muted: #6B7280;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

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

body {
    font-family: var(--font-family);
    background: linear-gradient(135deg, var(--color-background) 0%, var(--aws-squid-ink) 100%);
    color: var(--color-text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Header */
.header {
    background: rgba(26, 31, 46, 0.8);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 153, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-md);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) 0;
}

.logo {
    font-size: 1.75rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo-aws {
    color: var(--color-primary);
    font-weight: 700;
}

.logo-name {
    color: var(--color-text-primary);
    font-weight: 400;
}

.nav {
    display: flex;
    gap: var(--spacing-sm);
}

.nav-btn {
    background: transparent;
    border: none;
    color: var(--color-text-secondary);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-md);
    cursor: pointer;
    font-size: 0.95rem;
    font-weight: 500;
    transition: all var(--transition-base);
    position: relative;
}

.nav-btn:hover {
    color: var(--color-text-primary);
    background: rgba(255, 153, 0, 0.1);
}

.nav-btn.active {
    color: var(--color-primary);
    background: rgba(255, 153, 0, 0.15);
}

.nav-btn.active::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--color-primary);
}

/* Main */
.main {
    padding: var(--spacing-xl) 0;
    min-height: calc(100vh - 200px);
}

.screen {
    display: none;
    animation: fadeIn var(--transition-base);
}

.screen.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Hero Section */
.hero {
    text-align: center;
    padding: var(--spacing-2xl) 0;
}

.hero-content {
    margin-bottom: var(--spacing-xl);
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto var(--spacing-xl);
}

.hero-actions {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    max-width: 800px;
    margin: 0 auto;
}

.stat-card {
    background: rgba(26, 31, 46, 0.6);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 153, 0, 0.2);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    text-align: center;
    transition: all var(--transition-base);
}

.stat-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-primary);
    box-shadow: 0 10px 30px rgba(255, 153, 0, 0.2);
}

.stat-value {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
}

.stats-actions {
    text-align: center;
    margin-top: var(--spacing-lg);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-lg);
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
    font-family: var(--font-family);
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--aws-orange-dark) 100%);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    background: linear-gradient(135deg, var(--aws-orange-dark) 0%, var(--color-primary) 100%);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: var(--color-text-primary);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.3);
}

.btn-success {
    background: linear-gradient(135deg, var(--color-success) 0%, #27AE60 100%);
    color: white;
    box-shadow: var(--shadow-md);
}

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

.btn-lg {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 1.125rem;
}

.btn-sm {
    padding: var(--spacing-xs) var(--spacing-md);
    font-size: 0.875rem;
}

.btn-icon {
    width: 20px;
    height: 20px;
}

.btn-icon-only {
    background: transparent;
    border: none;
    color: var(--color-text-secondary);
    cursor: pointer;
    padding: var(--spacing-xs);
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-icon-only:hover:not(:disabled) {
    color: var(--color-error);
    background: rgba(231, 76, 60, 0.1);
}

.btn-icon-only:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

/* Screen Header */
.screen-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.screen-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text-primary);
}

.screen-subtitle {
    font-size: 1.125rem;
    color: var(--color-text-secondary);
}

/* Tabs */
.tabs {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    border-bottom: 2px solid rgba(255, 255, 255, 0.1);
}

.tab-btn {
    background: transparent;
    border: none;
    color: var(--color-text-secondary);
    padding: var(--spacing-md) var(--spacing-lg);
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    border-bottom: 2px solid transparent;
    margin-bottom: -2px;
    transition: all var(--transition-base);
}

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

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

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn var(--transition-base);
}

/* Card */
.card {
    background: rgba(26, 31, 46, 0.6);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 153, 0, 0.2);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-lg);
}

/* Forms */
.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-label {
    display: block;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    color: var(--color-text-primary);
}

.form-input {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    font-size: 1rem;
    font-family: var(--font-family);
    transition: all var(--transition-base);
}

.form-input:focus {
    outline: none;
    border-color: var(--color-primary);
    background: rgba(255, 255, 255, 0.08);
    box-shadow: 0 0 0 3px rgba(255, 153, 0, 0.1);
}

.form-input::placeholder {
    color: var(--color-text-muted);
}

/* Help Screen */
.help-content {
    max-width: 900px;
    margin: 0 auto;
}

.help-section {
    background: var(--color-card);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.help-section-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.help-text {
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin-bottom: var(--spacing-md);
}

.help-subsection {
    margin-top: var(--spacing-lg);
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.help-subsection h4 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
}

.code-example {
    margin: var(--spacing-md) 0;
}

.help-fields {
    margin-top: var(--spacing-lg);
}

.help-fields h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-text-primary);
    margin: var(--spacing-md) 0 var(--spacing-sm) 0;
}

.help-list {
    list-style: none;
    padding: 0;
    margin: var(--spacing-sm) 0;
}

.help-list li {
    padding: var(--spacing-sm) 0;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

.help-list code {
    background: rgba(255, 153, 0, 0.1);
    color: var(--color-primary);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 0.9em;
}

.help-steps {
    margin: var(--spacing-lg) 0;
}

.help-step {
    display: flex;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
    align-items: flex-start;
}

.step-number {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--color-primary), #ff7700);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: white;
}

.step-content {
    flex: 1;
}

.step-content h4 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
}

.step-content p {
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin: var(--spacing-xs) 0;
}

.help-note {
    background: rgba(255, 153, 0, 0.1);
    border-left: 4px solid var(--color-primary);
    padding: var(--spacing-md);
    border-radius: var(--radius-sm);
    margin-top: var(--spacing-lg);
    color: var(--color-text-secondary);
}

.error-list {
    display: grid;
    gap: var(--spacing-md);
}

.error-item {
    background: rgba(255, 0, 0, 0.05);
    border-left: 4px solid #ff4444;
    padding: var(--spacing-md);
    border-radius: var(--radius-sm);
    color: var(--color-text-secondary);
    line-height: 1.6;
}

.error-item strong {
    color: var(--color-text-primary);
}

.error-item code {
    background: rgba(255, 255, 255, 0.1);
    color: #ff9999;
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 0.9em;
}

textarea.form-input {
    resize: vertical;
    min-height: 100px;
}

.form-hint {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    margin-top: var(--spacing-xs);
}

.form-actions {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

/* Radio & Checkbox */
.radio-group {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.radio-label,
.checkbox-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    cursor: pointer;
    padding: var(--spacing-sm) var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
}

.radio-label:hover,
.checkbox-label:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: var(--color-primary);
}

.radio-label input[type="radio"],
.checkbox-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: var(--color-primary);
}

/* Options Container */
.option-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

.option-checkbox {
    width: 20px;
    height: 20px;
    cursor: pointer;
    accent-color: var(--color-primary);
    flex-shrink: 0;
}

.option-input {
    flex: 1;
}

/* Import Section */
.json-input {
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    min-height: 300px;
}

.import-help {
    margin-top: var(--spacing-xl);
    padding: var(--spacing-lg);
    background: rgba(0, 0, 0, 0.3);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--color-primary);
}

.import-help h4 {
    margin-bottom: var(--spacing-md);
    color: var(--color-primary);
}

.code-block {
    background: rgba(0, 0, 0, 0.5);
    padding: var(--spacing-md);
    border-radius: var(--radius-sm);
    overflow-x: auto;
    font-family: 'Courier New', monospace;
    font-size: 0.875rem;
    color: #A8DADC;
}

/* File Upload */
.file-upload-section {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.file-input {
    display: none;
}

.file-name {
    color: var(--color-text-secondary);
    font-size: 0.95rem;
}

.divider {
    display: flex;
    align-items: center;
    text-align: center;
    margin: var(--spacing-lg) 0;
    color: var(--color-text-muted);
}

.divider::before,
.divider::after {
    content: '';
    flex: 1;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.divider span {
    padding: 0 var(--spacing-md);
    font-weight: 600;
    font-size: 0.875rem;
}

/* Questions List */
.questions-list-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-md);
}

.questions-count {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-text-primary);
    margin: 0;
}

.questions-count span {
    color: var(--color-primary);
}

.questions-list {
    display: grid;
    gap: var(--spacing-md);
}

.question-item {
    background: rgba(26, 31, 46, 0.6);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    transition: all var(--transition-base);
}

.question-item:hover {
    border-color: var(--color-primary);
    transform: translateX(5px);
}

.question-item-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: var(--spacing-md);
}

.question-item-type {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-sm);
    background: rgba(255, 153, 0, 0.2);
    color: var(--color-primary);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.question-item-actions {
    display: flex;
    gap: var(--spacing-xs);
}

.question-item-text {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-md);
    color: var(--color-text-primary);
}

.question-item-options {
    display: grid;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-md);
}

.question-item-option {
    padding: var(--spacing-xs) var(--spacing-sm);
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
}

.question-item-option.correct {
    background: rgba(46, 204, 113, 0.2);
    border-left: 3px solid var(--color-success);
}

/* Exam Setup */
.exam-setup {
    max-width: 600px;
    margin: 0 auto;
}

/* Exam Progress */
.exam-header {
    margin-bottom: var(--spacing-xl);
}

.exam-info {
    text-align: center;
    margin-bottom: var(--spacing-md);
}

.exam-question-number {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-text-secondary);
}

.exam-progress-bar {
    height: 8px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 999px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    transition: width var(--transition-slow);
    border-radius: 999px;
}

/* Question Card */
.question-card {
    background: rgba(26, 31, 46, 0.6);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 153, 0, 0.2);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.question-type-badge {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-md);
    background: rgba(255, 153, 0, 0.2);
    color: var(--color-primary);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.question-text {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xl);
    line-height: 1.5;
}

.question-options {
    display: grid;
    gap: var(--spacing-md);
}

.option-label {
    display: flex;
    align-items: start;
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-lg);
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-base);
}

.option-label:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: var(--color-primary);
    transform: translateX(5px);
}

.option-label input {
    width: 20px;
    height: 20px;
    cursor: pointer;
    accent-color: var(--color-primary);
    flex-shrink: 0;
    margin-top: 2px;
}

.option-label.selected {
    background: rgba(255, 153, 0, 0.15);
    border-color: var(--color-primary);
}

.option-text {
    flex: 1;
    font-size: 1rem;
}

/* Exam Navigation */
.exam-navigation {
    display: flex;
    justify-content: space-between;
    gap: var(--spacing-md);
}

/* Results */
.results-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.score-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xl);
    padding: var(--spacing-xl);
    background: rgba(26, 31, 46, 0.6);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 153, 0, 0.2);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-xl);
}

.score-circle {
    position: relative;
    width: 200px;
    height: 200px;
}

.score-svg {
    transform: rotate(-90deg);
    width: 100%;
    height: 100%;
}

.score-bg {
    fill: none;
    stroke: rgba(255, 255, 255, 0.1);
    stroke-width: 12;
}

.score-progress {
    fill: none;
    stroke: var(--color-primary);
    stroke-width: 12;
    stroke-linecap: round;
    stroke-dasharray: 565.48;
    stroke-dashoffset: 565.48;
    transition: stroke-dashoffset 1s ease;
}

.score-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
}

.score-value {
    font-size: 3rem;
    font-weight: 700;
    color: var(--color-primary);
}

.score-label {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
}

.score-stats {
    display: flex;
    gap: var(--spacing-xl);
}

.score-stat {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
}

.score-stat-value {
    font-size: 2rem;
    font-weight: 700;
}

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

.score-stat-value.incorrect {
    color: var(--color-error);
}

.score-stat-label {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
}

.results-actions {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.section-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-lg);
    color: var(--color-text-primary);
}

.review-item {
    background: rgba(26, 31, 46, 0.6);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.review-item.correct {
    border-left: 4px solid var(--color-success);
}

.review-item.incorrect {
    border-left: 4px solid var(--color-error);
}

.review-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.review-status {
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 600;
}

.review-status.correct {
    background: rgba(46, 204, 113, 0.2);
    color: var(--color-success);
}

.review-status.incorrect {
    background: rgba(231, 76, 60, 0.2);
    color: var(--color-error);
}

.review-question {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.review-options {
    display: grid;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-md);
}

.review-option {
    padding: var(--spacing-sm) var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-sm);
    border-left: 3px solid transparent;
}

.review-option.user-answer {
    background: rgba(52, 152, 219, 0.2);
    border-left-color: var(--color-info);
}

.review-option.correct-answer {
    background: rgba(46, 204, 113, 0.2);
    border-left-color: var(--color-success);
}

.review-option.wrong-answer {
    background: rgba(231, 76, 60, 0.2);
    border-left-color: var(--color-error);
}

.review-explanation {
    padding: var(--spacing-md);
    background: rgba(0, 0, 0, 0.3);
    border-radius: var(--radius-md);
    border-left: 3px solid var(--color-primary);
    font-size: 0.95rem;
    color: var(--color-text-secondary);
}

/* Footer */
.footer {
    background: rgba(26, 31, 46, 0.8);
    border-top: 1px solid rgba(255, 153, 0, 0.1);
    padding: var(--spacing-lg) 0;
    text-align: center;
    color: var(--color-text-secondary);
    margin-top: var(--spacing-2xl);
}

/* Responsive */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .hero-actions {
        flex-direction: column;
    }

    .nav {
        flex-direction: column;
        gap: var(--spacing-xs);
    }

    .tabs {
        flex-direction: column;
        border-bottom: none;
    }

    .tab-btn {
        border-bottom: none;
        border-left: 2px solid transparent;
        margin-bottom: 0;
        margin-left: -2px;
    }

    .tab-btn.active {
        border-left-color: var(--color-primary);
    }

    .exam-navigation {
        flex-direction: column;
    }

    .score-stats {
        flex-direction: column;
        gap: var(--spacing-md);
    }
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: var(--spacing-2xl);
    color: var(--color-text-secondary);
}

.empty-state-icon {
    font-size: 4rem;
    margin-bottom: var(--spacing-md);
    opacity: 0.5;
}

.empty-state-text {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-md);
}