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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
}

img {
    max-width: 100%;
    height: auto;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

button {
    border: none;
    background: none;
    cursor: pointer;
    font-family: inherit;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.nav-brand .logo {
    height: 40px;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-link {
    font-weight: 500;
    transition: color 0.3s ease;
    padding: 0.5rem 0;
}

.nav-link:hover,
.nav-link.active {
    color: #007bff;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: #333;
    transition: 0.3s;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 6px;
    font-weight: 600;
    text-align: center;
    transition: all 0.3s ease;
    cursor: pointer;
    border: 2px solid transparent;
    font-size: 16px;
}

.btn-primary {
    background: #007bff;
    color: white;
    border-color: #007bff;
}

.btn-primary:hover {
    background: #0056b3;
    border-color: #0056b3;
}

.btn-outline {
    background: transparent;
    color: #007bff;
    border-color: #007bff;
}

.btn-outline:hover {
    background: #007bff;
    color: white;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 100px 0;
    text-align: center;
}

.hero-content h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.hero-content p {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Features Section */
.features {
    padding: 80px 0;
    background: #f8f9fa;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #333;
}

.feature-card p {
    color: #666;
}

/* Featured Courses Section */
.featured-courses {
    padding: 80px 0;
}

.featured-courses h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: #333;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.course-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.15);
}

.course-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.course-content {
    padding: 1.5rem;
}

.course-category {
    color: #007bff;
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 0.5rem;
}

.course-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: #333;
}

.course-description {
    color: #666;
    margin-bottom: 1rem;
    font-size: 0.9rem;
}

.course-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    font-size: 0.875rem;
    color: #666;
}

.course-price {
    font-size: 1.5rem;
    font-weight: 700;
    color: #007bff;
    margin-bottom: 1rem;
}

.course-actions {
    display: flex;
    gap: 0.5rem;
}

.btn-small {
    padding: 8px 16px;
    font-size: 14px;
}

.section-footer {
    text-align: center;
}

/* Page Header */
.page-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 60px 0;
    text-align: center;
}

.page-header h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.page-header p {
    font-size: 1.125rem;
    opacity: 0.9;
}

/* Courses Catalog */
.courses-catalog {
    padding: 60px 0;
}

.catalog-controls {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    align-items: center;
}

.search-box {
    flex: 1;
    min-width: 300px;
}

.search-box input {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #e9ecef;
    border-radius: 6px;
    font-size: 16px;
}

.search-box input:focus {
    outline: none;
    border-color: #007bff;
}

.filter-controls {
    display: flex;
    gap: 1rem;
}

.filter-controls select {
    padding: 12px 16px;
    border: 2px solid #e9ecef;
    border-radius: 6px;
    font-size: 16px;
    background: white;
    cursor: pointer;
}

.filter-controls select:focus {
    outline: none;
    border-color: #007bff;
}

/* Course Detail */
.course-detail {
    padding: 60px 0;
}

.course-detail-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
    margin-bottom: 3rem;
}

.course-detail-main h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #333;
}

.course-detail-meta {
    display: flex;
    gap: 2rem;
    margin: 1.5rem 0;
    flex-wrap: wrap;
}

.meta-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: #666;
    font-size: 0.9rem;
}

.course-detail-description {
    font-size: 1.125rem;
    color: #666;
    margin-bottom: 2rem;
}

.course-sections {
    margin-top: 3rem;
}

.course-section {
    margin-bottom: 3rem;
}

.course-section h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #333;
}

.course-section ul {
    list-style: disc;
    margin-left: 1.5rem;
}

.course-section li {
    margin-bottom: 0.5rem;
    color: #666;
}

.curriculum-list {
    background: #f8f9fa;
    border-radius: 8px;
    overflow: hidden;
}

.curriculum-item {
    padding: 1rem 1.5rem;
    border-bottom: 1px solid #e9ecef;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.curriculum-item:last-child {
    border-bottom: none;
}

.curriculum-title {
    font-weight: 500;
    color: #333;
}

.curriculum-duration {
    color: #666;
    font-size: 0.875rem;
}

.course-sidebar {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    height: fit-content;
    position: sticky;
    top: 100px;
}

.course-price-large {
    font-size: 2rem;
    font-weight: 700;
    color: #007bff;
    margin-bottom: 1.5rem;
}

.course-features {
    margin: 1.5rem 0;
}

.course-features li {
    padding: 0.5rem 0;
    color: #666;
    border-bottom: 1px solid #f1f3f4;
}

.course-features li:last-child {
    border-bottom: none;
}

.instructor-info {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid #e9ecef;
}

.instructor-name {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: #333;
}

.instructor-bio {
    color: #666;
    font-size: 0.9rem;
}

/* FAQ */
.faq-content {
    padding: 60px 0;
}

.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    border: 1px solid #e9ecef;
    border-radius: 8px;
    margin-bottom: 1rem;
    overflow: hidden;
}

.faq-question {
    width: 100%;
    padding: 1.5rem;
    text-align: left;
    background: white;
    border: none;
    font-size: 1.125rem;
    font-weight: 600;
    color: #333;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.faq-question:hover {
    background: #f8f9fa;
}

.faq-icon {
    font-size: 1.5rem;
    transition: transform 0.3s ease;
}

.faq-question[aria-expanded="true"] .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    padding: 0 1.5rem;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
}

.faq-answer.active {
    max-height: 200px;
    padding: 0 1.5rem 1.5rem;
}

.faq-answer p {
    color: #666;
    line-height: 1.6;
}

.faq-footer {
    text-align: center;
    margin-top: 3rem;
    padding: 2rem;
    background: #f8f9fa;
    border-radius: 8px;
}

.faq-footer h3 {
    margin-bottom: 1rem;
    color: #333;
}

.faq-footer p {
    color: #666;
    margin-bottom: 1.5rem;
}

/* Checkout */
.checkout {
    padding: 60px 0;
    background: #f8f9fa;
}

.checkout-header {
    text-align: center;
    margin-bottom: 3rem;
}

.checkout-header h1 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    color: #333;
}

.checkout-steps {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 2rem;
}

.step {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem;
    border-radius: 8px;
    background: white;
    color: #666;
}

.step.active {
    background: #007bff;
    color: white;
}

.step.completed {
    background: #28a745;
    color: white;
}

.step-number {
    width: 30px;
    height: 30px;
    border-radius: 50%;
    background: rgba(255,255,255,0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
}

.step-title {
    font-weight: 600;
}

.checkout-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
    max-width: 1000px;
    margin: 0 auto;
}

.checkout-form {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

.checkout-form h2 {
    margin-bottom: 2rem;
    color: #333;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #333;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #e9ecef;
    border-radius: 6px;
    font-size: 16px;
    transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #007bff;
}

.error-message {
    color: #dc3545;
    font-size: 0.875rem;
    margin-top: 0.25rem;
    display: none;
}

.error-message.show {
    display: block;
}

.form-group.error input,
.form-group.error select,
.form-group.error textarea {
    border-color: #dc3545;
}

.checkbox-group {
    margin: 2rem 0;
}

.checkbox-label {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    cursor: pointer;
    font-size: 0.9rem;
    line-height: 1.5;
}

.checkbox-label input[type="checkbox"] {
    width: auto;
    margin: 0;
}

.checkmark {
    width: 20px;
    height: 20px;
    border: 2px solid #e9ecef;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    margin-top: 2px;
}

.checkbox-label input[type="checkbox"]:checked + .checkmark {
    background: #007bff;
    border-color: #007bff;
}

.checkbox-label input[type="checkbox"]:checked + .checkmark::after {
    content: "✓";
    color: white;
    font-size: 12px;
    font-weight: bold;
}

.form-actions {
    display: flex;
    gap: 1rem;
    justify-content: space-between;
    margin-top: 2rem;
}

.checkout-sidebar {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    height: fit-content;
    position: sticky;
    top: 100px;
}

.order-summary h3 {
    margin-bottom: 1.5rem;
    color: #333;
}

.order-item {
    padding: 1rem 0;
    border-bottom: 1px solid #e9ecef;
}

.order-item:last-child {
    border-bottom: none;
}

.order-item-name {
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: #333;
}

.order-item-price {
    font-size: 1.25rem;
    font-weight: 700;
    color: #007bff;
}

.order-total {
    padding-top: 1rem;
    border-top: 2px solid #e9ecef;
    margin-top: 1rem;
}

.total-label {
    font-size: 1.125rem;
    font-weight: 600;
    color: #333;
}

.total-price {
    font-size: 1.5rem;
    font-weight: 700;
    color: #007bff;
}

.payment-security {
    background: #f8f9fa;
    padding: 1.5rem;
    border-radius: 8px;
    margin-bottom: 2rem;
    text-align: center;
}

.security-badges {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.payment-security p {
    color: #666;
    font-size: 0.9rem;
}

.demo-notice {
    background: #fff3cd;
    border: 1px solid #ffeaa7;
    padding: 1rem;
    border-radius: 6px;
    margin: 1.5rem 0;
}

.demo-notice p {
    color: #856404;
    margin: 0;
    font-size: 0.9rem;
}

/* Order Success */
.order-success {
    padding: 60px 0;
    text-align: center;
}

.success-content {
    max-width: 600px;
    margin: 0 auto;
}

.success-icon {
    margin-bottom: 2rem;
}

.order-success h1 {
    font-size: 2.5rem;
    color: #28a745;
    margin-bottom: 1rem;
}

.order-success p {
    font-size: 1.125rem;
    color: #666;
    margin-bottom: 2rem;
}

.order-details {
    background: #f8f9fa;
    padding: 2rem;
    border-radius: 8px;
    margin: 2rem 0;
    text-align: left;
}

.order-details h3 {
    margin-bottom: 1rem;
    color: #333;
}

.next-steps {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    margin: 2rem 0;
    text-align: left;
}

.next-steps h3 {
    margin-bottom: 1rem;
    color: #333;
}

.next-steps ul {
    list-style: disc;
    margin-left: 1.5rem;
}

.next-steps li {
    margin-bottom: 0.5rem;
    color: #666;
}

.success-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 2rem;
}

/* About Page */
.about-content {
    padding: 60px 0;
}

.about-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
}

.about-text h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: #333;
}

.about-text h3 {
    font-size: 1.5rem;
    margin: 2rem 0 1rem;
    color: #333;
}

.about-text p {
    color: #666;
    margin-bottom: 1.5rem;
    line-height: 1.7;
}

.about-text ul {
    list-style: disc;
    margin-left: 1.5rem;
    margin-bottom: 1.5rem;
}

.about-text li {
    margin-bottom: 0.5rem;
    color: #666;
}

.about-values h3 {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    color: #333;
}

.value-item {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    margin-bottom: 1.5rem;
}

.value-item h4 {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
    color: #007bff;
}

.value-item p {
    color: #666;
    font-size: 0.9rem;
}

.cta-section {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 60px 0;
    text-align: center;
}

.cta-content h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.cta-content p {
    font-size: 1.125rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

/* Contact Page */
.contact-content {
    padding: 60px 0;
}

.contact-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
}

.contact-form-section h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
    color: #333;
}

.contact-form {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

.form-success {
    background: #d4edda;
    color: #155724;
    padding: 1rem;
    border-radius: 6px;
    margin-top: 1rem;
}

.contact-info h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
    color: #333;
}

.contact-method {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    margin-bottom: 1.5rem;
}

.contact-method h3 {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
    color: #007bff;
}

.contact-method p {
    color: #666;
    margin-bottom: 0.5rem;
}

.contact-method a {
    color: #007bff;
    font-weight: 500;
}

.contact-method a:hover {
    text-decoration: underline;
}

/* Legal Pages */
.legal-content {
    padding: 60px 0;
}

.legal-document {
    max-width: 800px;
    margin: 0 auto;
    background: white;
    padding: 3rem;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

.legal-document h2 {
    font-size: 1.5rem;
    margin: 2rem 0 1rem;
    color: #333;
}

.legal-document p {
    color: #666;
    margin-bottom: 1rem;
    line-height: 1.7;
}

.legal-document ul {
    list-style: disc;
    margin-left: 1.5rem;
    margin-bottom: 1rem;
}

.legal-document li {
    margin-bottom: 0.5rem;
    color: #666;
}

.legal-document a {
    color: #007bff;
    text-decoration: underline;
}

/* Footer */
.footer {
    background: #2c3e50;
    color: white;
    padding: 60px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    margin-bottom: 1rem;
    color: white;
    font-size: 1.125rem;
}

.footer-section p,
.footer-section li {
    color: #bdc3c7;
    margin-bottom: 0.5rem;
    line-height: 1.6;
}

.footer-section ul {
    list-style: none;
}

.footer-section a {
    color: #bdc3c7;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: white;
}

.footer-logo {
    height: 40px;
    margin-bottom: 1rem;
}

.footer-bottom {
    border-top: 1px solid #34495e;
    padding-top: 2rem;
    text-align: center;
}

.footer-bottom p {
    color: #bdc3c7;
    margin: 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        box-shadow: 0 2px 10px rgba(0,0,0,0.1);
        flex-direction: column;
        padding: 1rem 0;
        gap: 0;
    }

    .nav-menu.active {
        display: flex;
    }

    .nav-link {
        padding: 1rem 2rem;
        width: 100%;
        border-bottom: 1px solid #f1f3f4;
    }

    .nav-toggle {
        display: flex;
    }

    .hero-content h1 {
        font-size: 2rem;
    }

    .hero-content p {
        font-size: 1rem;
    }

    .hero-actions {
        flex-direction: column;
        align-items: center;
    }

    .courses-grid {
        grid-template-columns: 1fr;
    }

    .course-detail-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .course-sidebar {
        position: static;
    }

    .checkout-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .checkout-sidebar {
        position: static;
        order: -1;
    }

    .checkout-steps {
        flex-direction: column;
        align-items: center;
        gap: 1rem;
    }

    .form-row {
        grid-template-columns: 1fr;
        gap: 0;
    }

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

    .about-grid,
    .contact-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .catalog-controls {
        flex-direction: column;
        align-items: stretch;
    }

    .search-box {
        min-width: auto;
    }

    .filter-controls {
        flex-direction: column;
    }

    .success-actions {
        flex-direction: column;
        align-items: center;
    }

    .page-header h1 {
        font-size: 2rem;
    }

    .page-header p {
        font-size: 1rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .hero {
        padding: 60px 0;
    }

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

    .featured-courses h2 {
        font-size: 2rem;
    }

    .course-card {
        margin: 0 -5px;
    }

    .checkout-form,
    .legal-document {
        padding: 1.5rem;
    }

    .btn {
        padding: 10px 20px;
        font-size: 14px;
    }
}

/* Focus and Accessibility */
*:focus {
    outline: 2px solid #007bff;
    outline-offset: 2px;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Animation and Transitions */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.6s ease-out;
}

/* Print Styles */
@media print {
    .header,
    .footer,
    .nav,
    .btn,
    .checkout-sidebar {
        display: none;
    }

    .container {
        max-width: none;
        padding: 0;
    }

    body {
        font-size: 12pt;
        line-height: 1.4;
    }

    h1, h2, h3, h4, h5, h6 {
        page-break-after: avoid;
    }

    .page-header {
        background: none;
        color: black;
        padding: 20px 0;
    }
}