/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --success-color: #16a34a;
    --success-bg: #dcfce7;
    --error-color: #dc2626;
    --error-bg: #fee2e2;
    --warning-color: #ca8a04;
    --warning-bg: #fef9c3;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    --border-radius: 8px;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1), 0 2px 4px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1), 0 4px 6px rgba(0, 0, 0, 0.05);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--gray-50);
    color: var(--gray-800);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
header {
    background: white;
    border-bottom: 1px solid var(--gray-200);
    padding: 1rem 2rem;
    position: sticky;
    top: 0;
    z-index: 100;
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--gray-900);
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 1.5rem;
}

.nav-links a {
    color: var(--gray-600);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-links a:hover {
    color: var(--primary-color);
}

/* Main Content */
main {
    flex: 1;
    padding: 2rem;
}

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

/* Hero Section */
.hero {
    text-align: center;
    padding: 3rem 1rem;
    background: linear-gradient(135deg, var(--primary-color), #7c3aed);
    color: white;
    border-radius: var(--border-radius);
    margin-bottom: 2rem;
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.hero .subtitle {
    font-size: 1.25rem;
    opacity: 0.9;
}

/* Buttons */
.btn-primary, .btn-secondary, .btn-outline, .btn-submit {
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
    display: inline-block;
    text-decoration: none;
    text-align: center;
}

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

.btn-primary:hover {
    background: var(--primary-hover);
}

.btn-secondary {
    background: var(--gray-200);
    color: var(--gray-700);
}

.btn-secondary:hover {
    background: var(--gray-300);
}

.btn-outline {
    background: transparent;
    color: var(--gray-600);
    border: 1px solid var(--gray-300);
}

.btn-outline:hover {
    background: var(--gray-100);
}

.btn-submit {
    background: var(--success-color);
    color: white;
}

.btn-submit:hover {
    background: #15803d;
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* Quiz Options Section */
.quiz-options {
    background: white;
    border-radius: var(--border-radius);
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
}

.quiz-options h2 {
    margin-bottom: 0.5rem;
}

.quiz-options > .description {
    color: var(--gray-500);
    margin-bottom: 1.5rem;
}

.quiz-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.quiz-card {
    border: 2px solid var(--gray-200);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    cursor: pointer;
    transition: all 0.2s;
    text-align: center;
}

.quiz-card:hover {
    border-color: var(--primary-color);
    background: var(--gray-50);
}

.quiz-card.selected {
    border-color: var(--primary-color);
    background: rgba(37, 99, 235, 0.05);
}

.quiz-card h3 {
    margin-bottom: 0.5rem;
    color: var(--gray-900);
}

.quiz-card .question-count {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.25rem;
}

.quiz-card .time-estimate {
    color: var(--gray-500);
    font-size: 0.875rem;
    margin-bottom: 0.5rem;
}

.quiz-card .description {
    color: var(--gray-600);
    font-size: 0.875rem;
}

#start-quiz {
    width: 100%;
    padding: 1rem;
    font-size: 1.125rem;
}

/* Categories Overview */
.categories-overview {
    background: white;
    border-radius: var(--border-radius);
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
}

.categories-overview h2 {
    margin-bottom: 1rem;
}

.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 0.75rem;
}

.category-item {
    display: flex;
    justify-content: space-between;
    padding: 0.75rem 1rem;
    background: var(--gray-50);
    border-radius: var(--border-radius);
    font-size: 0.875rem;
}

.category-name {
    font-weight: 500;
    color: var(--gray-700);
}

.category-count {
    color: var(--gray-500);
}

/* Info Section */
.info-section {
    background: white;
    border-radius: var(--border-radius);
    padding: 2rem;
    box-shadow: var(--shadow);
}

.info-section h2 {
    margin-bottom: 1rem;
}

.info-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.info-card {
    padding: 1rem;
    background: var(--gray-50);
    border-radius: var(--border-radius);
}

.info-card h3 {
    font-size: 1rem;
    margin-bottom: 0.5rem;
    color: var(--gray-800);
}

.info-card p {
    color: var(--gray-600);
    font-size: 0.875rem;
}

/* Quiz Page Styles */
.quiz-container {
    max-width: 800px;
    margin: 0 auto;
    background: white;
    border-radius: var(--border-radius);
    padding: 2rem;
    box-shadow: var(--shadow);
}

.quiz-header {
    margin-bottom: 1.5rem;
}

.progress-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    color: var(--gray-600);
}

.progress-bar {
    height: 8px;
    background: var(--gray-200);
    border-radius: 4px;
    overflow: hidden;
}

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

/* Question Navigation Dots */
.question-nav-bar {
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: var(--gray-50);
    border-radius: var(--border-radius);
    overflow-x: auto;
}

.question-dots {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    justify-content: center;
}

.question-dot {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    border: 2px solid var(--gray-300);
    background: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--gray-600);
    transition: all 0.2s;
}

.question-dot:hover {
    border-color: var(--primary-color);
}

.question-dot.current {
    border-color: var(--primary-color);
    background: var(--primary-color);
    color: white;
}

.question-dot.answered {
    border-color: var(--success-color);
    background: var(--success-color);
    color: white;
}

.question-dot.skipped {
    border-color: var(--warning-color);
    background: var(--warning-bg);
    color: var(--warning-color);
}

/* Question Area */
.question-area {
    margin-bottom: 2rem;
}

.question-meta {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.category-badge, .difficulty-badge {
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.category-badge {
    background: var(--gray-100);
    color: var(--gray-700);
}

.difficulty-badge {
    background: var(--primary-color);
    color: white;
}

.difficulty-badge.beginner {
    background: var(--success-color);
}

.difficulty-badge.intermediate {
    background: var(--warning-color);
}

.question-text {
    font-size: 1.25rem;
    color: var(--gray-900);
    margin-bottom: 1.5rem;
    line-height: 1.5;
}

/* Options */
.options-container {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.option {
    padding: 1rem 1.25rem;
    border: 2px solid var(--gray-200);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.option:hover {
    border-color: var(--primary-color);
    background: var(--gray-50);
}

.option.selected {
    border-color: var(--primary-color);
    background: rgba(37, 99, 235, 0.05);
}

.option-marker {
    width: 24px;
    height: 24px;
    border: 2px solid var(--gray-300);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 0.875rem;
    flex-shrink: 0;
}

.option.selected .option-marker {
    border-color: var(--primary-color);
    background: var(--primary-color);
    color: white;
}

.option-text {
    flex: 1;
}

/* Quiz Controls */
.quiz-controls {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.quiz-controls button {
    flex: 1;
}

.quiz-footer {
    display: flex;
    justify-content: space-between;
    padding-top: 1rem;
    border-top: 1px solid var(--gray-200);
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: white;
    border-radius: var(--border-radius);
    padding: 2rem;
    max-width: 600px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
}

.modal-close {
    float: right;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--gray-400);
}

.modal-close:hover {
    color: var(--gray-600);
}

.modal-content h2 {
    margin-bottom: 1rem;
}

.modal-actions {
    display: flex;
    gap: 1rem;
    justify-content: flex-end;
    margin-top: 1.5rem;
}

/* Review List */
.review-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.review-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem;
    background: var(--gray-50);
    border-radius: var(--border-radius);
    cursor: pointer;
}

.review-item:hover {
    background: var(--gray-100);
}

.review-number {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 0.75rem;
    flex-shrink: 0;
}

.review-item.answered .review-number {
    background: var(--success-color);
    color: white;
}

.review-item.skipped .review-number {
    background: var(--warning-bg);
    color: var(--warning-color);
}

.review-item.unanswered .review-number {
    background: var(--gray-200);
    color: var(--gray-600);
}

.review-question {
    flex: 1;
    font-size: 0.875rem;
    color: var(--gray-700);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.review-status {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

/* Submit Summary */
.submit-summary {
    background: var(--gray-50);
    padding: 1.5rem;
    border-radius: var(--border-radius);
}

.submit-summary p {
    margin-bottom: 0.5rem;
}

.submit-summary .warning {
    color: var(--warning-color);
    margin-top: 1rem;
}

/* Results Page */
.results-container {
    max-width: 1000px;
    margin: 0 auto;
}

.results-header {
    text-align: center;
    padding: 3rem 2rem;
    border-radius: var(--border-radius);
    margin-bottom: 2rem;
}

.results-header.passed {
    background: linear-gradient(135deg, var(--success-color), #22c55e);
    color: white;
}

.results-header.failed {
    background: linear-gradient(135deg, var(--error-color), #f87171);
    color: white;
}

.results-header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.results-header .score {
    font-size: 4rem;
    font-weight: 700;
    margin: 1rem 0;
}

.results-header .pass-status {
    font-size: 1.25rem;
    opacity: 0.9;
}

/* Results Grid */
.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.results-card {
    background: white;
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

.results-card.full-width {
    grid-column: 1 / -1;
}

.results-card h3 {
    margin-bottom: 1rem;
    color: var(--gray-800);
}

/* Score Summary */
.score-summary {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
}

.score-item {
    text-align: center;
    padding: 1rem;
    background: var(--gray-50);
    border-radius: var(--border-radius);
}

.score-item .value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--gray-900);
}

.score-item .label {
    font-size: 0.875rem;
    color: var(--gray-500);
}

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

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

.score-item.skipped .value {
    color: var(--warning-color);
}

/* Breakdown Lists */
.breakdown-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.breakdown-item {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.breakdown-label {
    width: 100px;
    font-weight: 500;
    text-transform: capitalize;
}

.breakdown-bar {
    flex: 1;
    height: 24px;
    background: var(--gray-200);
    border-radius: 12px;
    overflow: hidden;
    position: relative;
}

.breakdown-fill {
    height: 100%;
    border-radius: 12px;
    transition: width 0.5s ease;
}

.breakdown-fill.good {
    background: var(--success-color);
}

.breakdown-fill.okay {
    background: var(--warning-color);
}

.breakdown-fill.poor {
    background: var(--error-color);
}

.breakdown-percent {
    width: 50px;
    text-align: right;
    font-weight: 600;
}

/* Category Breakdown */
.category-breakdown {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1rem;
}

.category-item-result {
    padding: 1rem;
    background: var(--gray-50);
    border-radius: var(--border-radius);
    border-left: 4px solid var(--gray-300);
}

.category-item-result.good {
    border-left-color: var(--success-color);
}

.category-item-result.okay {
    border-left-color: var(--warning-color);
}

.category-item-result.poor {
    border-left-color: var(--error-color);
}

.category-item-result .category-name {
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.category-item-result .category-stats {
    display: flex;
    justify-content: space-between;
    font-size: 0.875rem;
    color: var(--gray-600);
}

.category-item-result .category-percent {
    font-weight: 700;
}

/* Weak Areas */
.section-description {
    color: var(--gray-500);
    margin-bottom: 1rem;
    font-size: 0.875rem;
}

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

.weak-area-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: var(--error-bg);
    border-radius: var(--border-radius);
    border-left: 4px solid var(--error-color);
}

.weak-area-item .area-name {
    flex: 1;
    font-weight: 500;
}

.weak-area-item .area-score {
    font-weight: 700;
    color: var(--error-color);
}

/* Filter Buttons */
.filter-buttons {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.5rem 1rem;
    border: 1px solid var(--gray-300);
    border-radius: 9999px;
    background: white;
    cursor: pointer;
    font-size: 0.875rem;
    transition: all 0.2s;
}

.filter-btn:hover {
    background: var(--gray-100);
}

.filter-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* Questions Review */
.questions-review {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.question-review-item {
    padding: 1.5rem;
    border-radius: var(--border-radius);
    border: 1px solid var(--gray-200);
}

.question-review-item.correct {
    background: var(--success-bg);
    border-color: var(--success-color);
}

.question-review-item.incorrect {
    background: var(--error-bg);
    border-color: var(--error-color);
}

.question-review-item.skipped {
    background: var(--warning-bg);
    border-color: var(--warning-color);
}

.question-review-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 0.75rem;
}

.question-review-number {
    font-weight: 600;
    color: var(--gray-600);
}

.question-review-badges {
    display: flex;
    gap: 0.5rem;
}

.question-review-text {
    font-weight: 500;
    margin-bottom: 1rem;
    color: var(--gray-900);
}

.answer-info {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    font-size: 0.875rem;
}

.your-answer, .correct-answer-text {
    padding: 0.5rem 0.75rem;
    border-radius: var(--border-radius);
}

.your-answer {
    background: rgba(0, 0, 0, 0.05);
}

.correct-answer-text {
    background: rgba(22, 163, 74, 0.1);
    color: var(--success-color);
    font-weight: 500;
}

.explanation {
    margin-top: 1rem;
    padding: 1rem;
    background: rgba(0, 0, 0, 0.03);
    border-radius: var(--border-radius);
    font-size: 0.875rem;
    color: var(--gray-700);
}

.explanation strong {
    color: var(--gray-900);
}

/* Results Actions */
.results-actions {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 2rem;
}

/* Footer */
footer {
    background: white;
    border-top: 1px solid var(--gray-200);
    padding: 1.5rem;
    text-align: center;
    color: var(--gray-500);
    font-size: 0.875rem;
}

/* Responsive */
@media (max-width: 768px) {
    main {
        padding: 1rem;
    }

    .hero {
        padding: 2rem 1rem;
    }

    .hero h1 {
        font-size: 1.75rem;
    }

    .quiz-controls {
        flex-wrap: wrap;
    }

    .quiz-footer {
        flex-direction: column;
        gap: 0.75rem;
    }

    .quiz-footer button {
        width: 100%;
    }

    .results-header .score {
        font-size: 3rem;
    }

    .modal-content {
        padding: 1.5rem;
    }
}