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

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

.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: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
}

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

.logo img {
    height: 40px;
    width: auto;
}

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

.nav-link {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s ease;
    padding: 0.5rem 0;
}

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

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

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

/* Main Content */
main {
    margin-top: 80px;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 4rem 0;
    text-align: center;
}

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

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    opacity: 0.9;
}

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

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: 2px solid transparent;
    cursor: pointer;
    font-size: 1rem;
}

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

.btn-primary:hover {
    background: #5855eb;
    transform: translateY(-2px);
}

.btn-secondary {
    background: transparent;
    color: white;
    border-color: white;
}

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

/* Trust Indicators */
.trust-indicators {
    padding: 4rem 0;
    background: #f8fafc;
}

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

.trust-item {
    text-align: center;
    padding: 2rem;
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.trust-icon {
    margin-bottom: 1rem;
}

.trust-item h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: #1f2937;
}

.trust-item p {
    color: #6b7280;
}

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

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

.section-header h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #1f2937;
}

.section-header p {
    font-size: 1.125rem;
    color: #6b7280;
    max-width: 600px;
    margin: 0 auto;
}

.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 6px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    text-decoration: none;
    color: inherit;
}

.course-card:hover {
    transform: translateY(-4px);
    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-category {
    display: inline-block;
    background: #e0e7ff;
    color: #6366f1;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 1rem;
}

.course-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: #1f2937;
}

.course-description {
    color: #6b7280;
    margin-bottom: 1rem;
    line-height: 1.5;
}

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

.course-difficulty {
    font-size: 0.875rem;
    color: #6b7280;
}

.course-duration {
    font-size: 0.875rem;
    color: #6b7280;
}

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

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

/* Course Details Page */
.course-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 3rem 0;
}

.course-header-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
    align-items: center;
}

.course-details {
    padding: 3rem 0;
}

.course-tabs {
    display: flex;
    border-bottom: 2px solid #e5e7eb;
    margin-bottom: 2rem;
}

.tab-button {
    background: none;
    border: none;
    padding: 1rem 2rem;
    cursor: pointer;
    font-weight: 600;
    color: #6b7280;
    border-bottom: 3px solid transparent;
    transition: all 0.3s ease;
}

.tab-button.active {
    color: #6366f1;
    border-bottom-color: #6366f1;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

/* 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;
    border: 2px solid #d1d5db;
    border-radius: 6px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-input:focus {
    outline: none;
    border-color: #6366f1;
}

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

/* Checkout */
.checkout-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem 0;
}

.checkout-steps {
    display: flex;
    justify-content: center;
    margin-bottom: 3rem;
}

.step {
    display: flex;
    align-items: center;
    padding: 1rem;
    background: #f3f4f6;
    margin: 0 0.5rem;
    border-radius: 8px;
    color: #6b7280;
}

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

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

.payment-icon {
    width: 40px;
    height: 25px;
    background: #f3f4f6;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Footer */
.footer {
    background: #1f2937;
    color: white;
    padding: 3rem 0 1rem;
}

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

.footer-section h3 {
    margin-bottom: 1rem;
    color: #f9fafb;
}

.footer-links {
    list-style: none;
}

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

.footer-links a {
    color: #d1d5db;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: #6366f1;
}

.footer-description {
    color: #d1d5db;
    margin-bottom: 1.5rem;
}

.footer-contact p {
    color: #d1d5db;
    margin-bottom: 0.5rem;
}

.footer-contact a {
    color: #6366f1;
    text-decoration: none;
}

.footer-bottom {
    border-top: 1px solid #374151;
    padding-top: 1rem;
    text-align: center;
    color: #9ca3af;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-list {
        display: none;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-cta {
        flex-direction: column;
        align-items: center;
    }
    
    .courses-grid {
        grid-template-columns: 1fr;
    }
    
    .course-header-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .checkout-steps {
        flex-direction: column;
        align-items: center;
    }
    
    .step {
        margin: 0.5rem 0;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .hero {
        padding: 2rem 0;
    }
    
    .trust-grid {
        grid-template-columns: 1fr;
    }
    
    .course-tabs {
        flex-wrap: wrap;
    }
    
    .tab-button {
        flex: 1;
        min-width: 120px;
    }
}

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