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

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

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

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

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: #2563eb;
    font-size: 1.25rem;
    font-weight: 700;
}

.nav-logo img {
    height: 32px;
    margin-right: 10px;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: #64748b;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: #2563eb;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: #333;
    margin: 3px 0;
    transition: 0.3s;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border: none;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1rem;
    line-height: 1.5;
}

.btn-primary {
    background: #2563eb;
    color: white;
}

.btn-primary:hover {
    background: #1d4ed8;
    transform: translateY(-1px);
}

.btn-secondary {
    background: transparent;
    color: #2563eb;
    border: 2px solid #2563eb;
}

.btn-secondary:hover {
    background: #2563eb;
    color: white;
}

.btn-full {
    width: 100%;
}

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

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-content h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

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

.hero-actions {
    display: flex;
    gap: 1rem;
}

.hero-image img {
    width: 100%;
    height: auto;
}

/* Features Section */
.features {
    padding: 100px 0;
    background: #f8fafc;
}

.features h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: #1e293b;
}

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

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #1e293b;
}

.feature-card p {
    color: #64748b;
}

/* Featured Courses Section */
.featured-courses {
    padding: 100px 0;
}

.featured-courses h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: #1e293b;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.course-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

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

.course-content {
    padding: 1.5rem;
}

.course-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.course-category {
    background: #e0e7ff;
    color: #3730a3;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 600;
}

.course-difficulty {
    color: #64748b;
    font-size: 0.875rem;
}

.course-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: #1e293b;
}

.course-description {
    color: #64748b;
    margin-bottom: 1rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.course-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.course-price {
    font-size: 1.5rem;
    font-weight: 700;
    color: #2563eb;
}

.course-duration {
    color: #64748b;
    font-size: 0.875rem;
}

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

/* Page Header */
.page-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 80px 0;
    text-align: center;
}

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

.page-header p {
    font-size: 1.25rem;
    opacity: 0.9;
}

/* Catalog Filters */
.catalog-filters {
    background: #f8fafc;
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 3rem;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

.filter-group {
    display: flex;
    flex-direction: column;
}

.filter-group label {
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: #1e293b;
}

.search-input,
.filter-select {
    padding: 0.75rem;
    border: 1px solid #d1d5db;
    border-radius: 6px;
    font-size: 1rem;
}

.search-input:focus,
.filter-select:focus {
    outline: none;
    border-color: #2563eb;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

/* Course Detail Page */
.course-detail {
    padding: 50px 0;
}

.course-header {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 3rem;
    margin-bottom: 3rem;
}

.course-info h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: #1e293b;
}

.course-info .course-meta {
    margin-bottom: 1.5rem;
}

.course-info .course-description {
    font-size: 1.125rem;
    color: #64748b;
    margin-bottom: 2rem;
}

.course-sidebar {
    background: #f8fafc;
    padding: 2rem;
    border-radius: 12px;
    height: fit-content;
}

.course-sidebar img {
    width: 100%;
    border-radius: 8px;
    margin-bottom: 1.5rem;
}

.price-info {
    text-align: center;
    margin-bottom: 1.5rem;
}

.price-info .course-price {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

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

.course-main h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: #1e293b;
}

.course-main h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #1e293b;
}

.course-main ul {
    margin-left: 1.5rem;
    margin-bottom: 2rem;
}

.course-main li {
    margin-bottom: 0.5rem;
    color: #64748b;
}

.curriculum-item {
    background: white;
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 1rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

.curriculum-item h4 {
    color: #1e293b;
    margin-bottom: 0.5rem;
}

.instructor-info {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 2rem;
}

.instructor-info h3 {
    margin-bottom: 1rem;
}

.instructor-info h4 {
    color: #2563eb;
    margin-bottom: 0.5rem;
}

.faq-item {
    background: white;
    border-radius: 8px;
    margin-bottom: 1rem;
    overflow: hidden;
}

.faq-question {
    width: 100%;
    padding: 1rem;
    background: none;
    border: none;
    text-align: left;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: #1e293b;
}

.faq-question:hover {
    background: #f8fafc;
}

.faq-answer {
    padding: 0 1rem 1rem;
    color: #64748b;
    display: none;
}

.faq-answer.active {
    display: block;
}

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

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

/* Checkout Styles */
.checkout {
    padding: 50px 0;
}

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

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

.step {
    padding: 0.5rem 1rem;
    border-radius: 20px;
    background: #e5e7eb;
    color: #6b7280;
    font-weight: 600;
}

.step.active {
    background: #2563eb;
    color: white;
}

.step.completed {
    background: #10b981;
    color: white;
}

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

.checkout-form {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}

.order-summary {
    background: #f8fafc;
    padding: 2rem;
    border-radius: 12px;
    height: fit-content;
}

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

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

.form-group label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: #1e293b;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #d1d5db;
    border-radius: 6px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #2563eb;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-group.error input,
.form-group.error select,
.form-group.error textarea {
    border-color: #ef4444;
}

.error-message {
    color: #ef4444;
    font-size: 0.875rem;
    margin-top: 0.25rem;
    display: none;
}

.form-group.error .error-message {
    display: block;
}

.checkbox-group {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
}

.checkbox-label {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    cursor: pointer;
    font-size: 0.875rem;
    line-height: 1.5;
}

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

.checkmark {
    width: 20px;
    height: 20px;
    border: 2px solid #d1d5db;
    border-radius: 4px;
    position: relative;
    flex-shrink: 0;
    margin-top: 2px;
}

.checkbox-label input[type="checkbox"]:checked + .checkmark {
    background: #2563eb;
    border-color: #2563eb;
}

.checkbox-label input[type="checkbox"]:checked + .checkmark::after {
    content: '✓';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: white;
    font-size: 12px;
    font-weight: bold;
}

.trust-badges {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    margin-bottom: 2rem;
    padding: 1rem;
    background: #f0f9ff;
    border-radius: 8px;
}

.trust-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
    color: #1e293b;
}

.demo-notice {
    background: #fef3c7;
    border: 1px solid #f59e0b;
    padding: 1rem;
    border-radius: 6px;
    margin-bottom: 1.5rem;
}

.demo-notice p {
    margin: 0;
    color: #92400e;
    font-size: 0.875rem;
}

/* Order Success */
.order-success {
    padding: 100px 0;
    text-align: center;
}

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

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

.success-content h1 {
    font-size: 3rem;
    color: #10b981;
    margin-bottom: 1rem;
}

.success-message {
    font-size: 1.25rem;
    color: #64748b;
    margin-bottom: 3rem;
}

.order-details {
    background: #f8fafc;
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 3rem;
    text-align: left;
}

.next-steps {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 3rem;
    text-align: left;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}

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

.next-steps li {
    margin-bottom: 0.5rem;
    color: #64748b;
}

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

/* About Page */
.about-content {
    padding: 50px 0;
}

.about-section {
    margin-bottom: 4rem;
}

.about-section h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: #1e293b;
}

.about-section h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #1e293b;
}

.about-section p {
    font-size: 1.125rem;
    color: #64748b;
    margin-bottom: 1.5rem;
    line-height: 1.7;
}

.about-section ul {
    margin-left: 1.5rem;
    margin-bottom: 2rem;
}

.about-section li {
    margin-bottom: 0.5rem;
    color: #64748b;
    font-size: 1.125rem;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

/* Contact Page */
.contact-content {
    padding: 50px 0;
}

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

.contact-form {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}

.contact-info {
    background: #f8fafc;
    padding: 2rem;
    border-radius: 12px;
}

.contact-item {
    margin-bottom: 2rem;
}

.contact-item h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: #1e293b;
}

.contact-item p {
    color: #64748b;
    line-height: 1.6;
}

.contact-item a {
    color: #2563eb;
    text-decoration: none;
}

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

/* FAQ Page */
.faq-content {
    padding: 50px 0;
}

.faq-list {
    margin-bottom: 4rem;
}

.faq-contact {
    text-align: center;
    background: #f8fafc;
    padding: 3rem;
    border-radius: 12px;
}

.faq-contact h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: #1e293b;
}

.faq-contact p {
    font-size: 1.125rem;
    color: #64748b;
    margin-bottom: 2rem;
}

/* Legal Pages */
.legal-page {
    padding: 50px 0;
}

.legal-content {
    max-width: 800px;
    margin: 0 auto;
}

.legal-content h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #1e293b;
}

.last-updated {
    color: #64748b;
    font-style: italic;
    margin-bottom: 3rem;
}

.legal-content section {
    margin-bottom: 3rem;
}

.legal-content h2 {
    font-size: 1.75rem;
    margin-bottom: 1rem;
    color: #1e293b;
}

.legal-content h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    color: #1e293b;
}

.legal-content p {
    margin-bottom: 1rem;
    color: #64748b;
    line-height: 1.7;
}

.legal-content ul {
    margin-left: 1.5rem;
    margin-bottom: 1.5rem;
}

.legal-content li {
    margin-bottom: 0.5rem;
    color: #64748b;
}

.contact-info {
    background: #f8fafc;
    padding: 1.5rem;
    border-radius: 8px;
    margin-top: 1rem;
}

/* Footer */
.footer {
    background: #1e293b;
    color: white;
    padding: 50px 0 20px;
}

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

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

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: white;
}

.footer-section p {
    color: #cbd5e1;
    line-height: 1.6;
}

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

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: #cbd5e1;
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.footer-bottom {
    border-top: 1px solid #374151;
    padding-top: 1.5rem;
    text-align: center;
    color: #cbd5e1;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-content h1 {
        font-size: 2rem;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .courses-grid {
        grid-template-columns: 1fr;
    }
    
    .catalog-filters {
        grid-template-columns: 1fr;
    }
    
    .course-header {
        grid-template-columns: 1fr;
    }
    
    .course-details {
        grid-template-columns: 1fr;
    }
    
    .checkout-content {
        grid-template-columns: 1fr;
    }
    
    .contact-grid {
        grid-template-columns: 1fr;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .hero-actions,
    .success-actions,
    .cta-buttons {
        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;
    }
    
    .nav-container {
        padding: 0 15px;
    }
    
    .hero {
        padding: 50px 0;
    }
    
    .features,
    .featured-courses {
        padding: 50px 0;
    }
    
    .course-card {
        margin: 0 10px;
    }
    
    .checkout-form,
    .contact-form,
    .contact-info {
        padding: 1.5rem;
    }
}

/* Focus states for accessibility */
.btn:focus,
input:focus,
select:focus,
textarea:focus,
.nav-link:focus {
    outline: 2px solid #2563eb;
    outline-offset: 2px;
}

/* Print styles */
@media print {
    .header,
    .footer,
    .nav-toggle,
    .btn {
        display: none;
    }
    
    body {
        font-size: 12pt;
        line-height: 1.4;
    }
    
    .container {
        max-width: none;
        padding: 0;
    }
}