/* 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;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

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

.nav-wrapper {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 700;
    font-size: 1.25rem;
    color: #6366f1;
}

.nav-list {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: #64748b;
    font-weight: 500;
    transition: color 0.2s;
    padding: 0.5rem 0;
    border-bottom: 2px solid transparent;
}

.nav-link:hover,
.nav-link.active {
    color: #6366f1;
    border-bottom-color: #6366f1;
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

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

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.2s;
    border: 2px solid transparent;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background: #6366f1;
    color: white;
}

.btn-primary:hover {
    background: #5855eb;
    transform: translateY(-1px);
}

.btn-secondary {
    background: transparent;
    color: #6366f1;
    border-color: #6366f1;
}

.btn-secondary:hover {
    background: #6366f1;
    color: white;
}

.btn-outline {
    background: transparent;
    color: #374151;
    border-color: #d1d5db;
}

.btn-outline:hover {
    background: #f9fafb;
    border-color: #6366f1;
    color: #6366f1;
}

/* Hero Section */
.hero {
    padding: 4rem 0;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: url('/assets/pattern-bg.svg');
    background-size: 100px 100px;
    opacity: 0.05;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
    position: relative;
}

.hero-content h1 {
    font-size: 3rem;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    color: #1e293b;
}

.hero-content p {
    font-size: 1.25rem;
    color: #64748b;
    margin-bottom: 2rem;
}

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

/* Trust Indicators */
.trust-indicators {
    padding: 3rem 0;
    background: #f8fafc;
}

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

.trust-item {
    text-align: center;
    padding: 1.5rem;
}

.trust-icon {
    width: 60px;
    height: 60px;
    background: #6366f1;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
    color: white;
}

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

.trust-item p {
    color: #64748b;
}

/* Featured Courses */
.featured-courses {
    padding: 4rem 0;
}

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

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: #1e293b;
}

.section-header p {
    font-size: 1.125rem;
    color: #64748b;
}

.section-footer {
    text-align: center;
    margin-top: 3rem;
}

/* Course Grid */
.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.course-card {
    background: white;
    border-radius: 1rem;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    transition: transform 0.2s, box-shadow 0.2s;
    border: 1px solid #e2e8f0;
}

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

.course-image {
    height: 200px;
    overflow: hidden;
    position: relative;
}

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

.course-label {
    position: absolute;
    top: 1rem;
    left: 1rem;
    background: #6366f1;
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-size: 0.875rem;
    font-weight: 600;
}

.course-content {
    padding: 1.5rem;
}

.course-category {
    color: #6366f1;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.course-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    color: #1e293b;
    line-height: 1.3;
}

.course-description {
    color: #64748b;
    margin-bottom: 1rem;
    line-height: 1.5;
}

.course-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    font-size: 0.875rem;
    color: #64748b;
}

.course-difficulty {
    background: #f1f5f9;
    padding: 0.25rem 0.5rem;
    border-radius: 0.25rem;
    font-weight: 500;
}

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

.course-price {
    font-size: 1.5rem;
    font-weight: 700;
    color: #059669;
}

/* Course Catalog */
.page-header {
    padding: 3rem 0;
    background: #f8fafc;
    text-align: center;
}

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

.course-filters {
    padding: 2rem 0;
    background: white;
    border-bottom: 1px solid #e2e8f0;
}

.filters-row {
    display: flex;
    gap: 1rem;
    align-items: center;
    flex-wrap: wrap;
}

.filter-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.filter-group label {
    font-weight: 500;
    color: #374151;
}

.filter-input {
    padding: 0.5rem 1rem;
    border: 1px solid #d1d5db;
    border-radius: 0.5rem;
    font-size: 1rem;
}

.filter-input:focus {
    outline: none;
    border-color: #6366f1;
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

/* Course Detail Page */
.course-detail {
    padding: 3rem 0;
}

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

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

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

.meta-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: #64748b;
}

.course-detail-description {
    font-size: 1.125rem;
    line-height: 1.7;
    margin-bottom: 3rem;
    color: #374151;
}

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

.detail-section h2 {
    font-size: 1.75rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: #1e293b;
}

.detail-section h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #1e293b;
}

.detail-list {
    list-style: none;
    margin-bottom: 1.5rem;
}

.detail-list li {
    padding: 0.5rem 0;
    border-bottom: 1px solid #f1f5f9;
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
}

.detail-list li::before {
    content: '✓';
    color: #059669;
    font-weight: bold;
    flex-shrink: 0;
}

.curriculum-item {
    background: #f8fafc;
    padding: 1rem;
    border-radius: 0.5rem;
    margin-bottom: 0.75rem;
    border-left: 4px solid #6366f1;
}

.instructor-card {
    background: #f8fafc;
    padding: 2rem;
    border-radius: 1rem;
    margin-bottom: 2rem;
}

.instructor-name {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #1e293b;
}

.faq-item {
    border: 1px solid #e2e8f0;
    border-radius: 0.5rem;
    margin-bottom: 1rem;
    overflow: hidden;
}

.faq-question {
    background: #f8fafc;
    padding: 1rem 1.5rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.faq-answer {
    padding: 1rem 1.5rem;
    display: none;
    line-height: 1.6;
    color: #374151;
}

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

.course-sidebar {
    position: sticky;
    top: 2rem;
    height: fit-content;
}

.course-purchase-card {
    background: white;
    border: 1px solid #e2e8f0;
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

.course-price-display {
    text-align: center;
    margin-bottom: 2rem;
}

.course-price-display .price {
    font-size: 3rem;
    font-weight: 700;
    color: #059669;
}

.purchase-features {
    margin-bottom: 2rem;
}

.purchase-features li {
    padding: 0.5rem 0;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: #374151;
}

.purchase-features li::before {
    content: '✓';
    color: #059669;
    font-weight: bold;
}

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

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #374151;
}

.form-input {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid #d1d5db;
    border-radius: 0.5rem;
    font-size: 1rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-input:focus {
    outline: none;
    border-color: #6366f1;
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-error {
    color: #dc2626;
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

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

.checkbox-group {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}

.checkbox-group input[type="checkbox"] {
    margin-top: 0.25rem;
}

.checkbox-group label {
    font-size: 0.875rem;
    line-height: 1.5;
    color: #374151;
}

/* Checkout */
.checkout-header {
    padding: 2rem 0;
    background: #f8fafc;
    border-bottom: 1px solid #e2e8f0;
}

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

.step {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: 2rem;
    background: #f1f5f9;
    color: #64748b;
}

.step.active {
    background: #6366f1;
    color: white;
}

.step.completed {
    background: #059669;
    color: white;
}

.checkout-content {
    padding: 3rem 0;
}

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

.checkout-form {
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    border: 1px solid #e2e8f0;
}

.checkout-summary {
    background: #f8fafc;
    padding: 2rem;
    border-radius: 1rem;
    height: fit-content;
    position: sticky;
    top: 2rem;
}

.summary-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
    border-bottom: 1px solid #e2e8f0;
}

.summary-total {
    font-size: 1.25rem;
    font-weight: 700;
    color: #1e293b;
    border-bottom: none;
    margin-top: 1rem;
}

.payment-icons {
    display: flex;
    gap: 1rem;
    align-items: center;
    margin: 1rem 0;
}

.payment-icon {
    width: 40px;
    height: 25px;
    background: #f1f5f9;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 600;
    color: #64748b;
}

/* Order Success */
.success-page {
    padding: 4rem 0;
    text-align: center;
}

.success-icon {
    width: 80px;
    height: 80px;
    background: #059669;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 2rem;
    color: white;
    font-size: 2rem;
}

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

.order-details {
    background: #f8fafc;
    padding: 2rem;
    border-radius: 1rem;
    margin: 2rem auto;
    max-width: 600px;
    text-align: left;
}

/* Contact Page */
.contact-content {
    padding: 3rem 0;
}

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

.contact-info {
    background: #f8fafc;
    padding: 2rem;
    border-radius: 1rem;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.contact-icon {
    width: 40px;
    height: 40px;
    background: #6366f1;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

/* Footer */
.footer {
    background: #1e293b;
    color: #cbd5e1;
    padding: 3rem 0 1rem;
    margin-top: 4rem;
}

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

.footer-section h4 {
    color: white;
    margin-bottom: 1rem;
    font-weight: 600;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
    color: white;
    font-weight: 700;
    font-size: 1.25rem;
}

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

.footer-section a {
    color: #cbd5e1;
    transition: color 0.2s;
}

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

.footer-bottom {
    border-top: 1px solid #374151;
    padding-top: 1rem;
    text-align: center;
    color: #94a3b8;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-list {
        display: none;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-content h1 {
        font-size: 2rem;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .trust-grid {
        grid-template-columns: 1fr;
    }
    
    .courses-grid {
        grid-template-columns: 1fr;
    }
    
    .course-detail-grid {
        grid-template-columns: 1fr;
    }
    
    .checkout-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-grid {
        grid-template-columns: 1fr;
    }
    
    .filters-row {
        flex-direction: column;
        align-items: stretch;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .checkout-steps {
        flex-direction: column;
        align-items: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 0.5rem;
    }
    
    .hero-content h1 {
        font-size: 1.75rem;
    }
    
    .section-header h2 {
        font-size: 2rem;
    }
    
    .course-card {
        margin: 0 0.5rem;
    }
    
    .btn {
        padding: 0.5rem 1rem;
        font-size: 0.875rem;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

.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;
}

/* Focus styles */
a:focus,
button:focus,
input:focus,
select:focus,
textarea:focus {
    outline: 2px solid #6366f1;
    outline-offset: 2px;
}