* {
    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 */
.header {
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
    max-width: 1200px;
    margin: 0 auto;
}

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

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    margin: 0;
}

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

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

.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;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 80px 20px;
    display: flex;
    align-items: center;
    min-height: 500px;
}

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

.hero h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

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

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

.hero-image img {
    width: 100%;
    height: auto;
    max-width: 500px;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 8px;
    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: #5856eb;
    transform: translateY(-2px);
}

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

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

/* Features Section */
.features {
    padding: 80px 20px;
    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(280px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    transition: transform 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
}

.feature-icon {
    color: #6366f1;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: #1e293b;
}

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

/* Featured Courses */
.featured-courses {
    padding: 80px 20px;
}

.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(350px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.course-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    transition: transform 0.3s ease;
}

.course-card:hover {
    transform: translateY(-5px);
}

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

.course-content {
    padding: 1.5rem;
}

.course-meta {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    font-size: 0.875rem;
    color: #64748b;
}

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

.course-title a {
    text-decoration: none;
    color: inherit;
}

.course-title a:hover {
    color: #6366f1;
}

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

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

.course-price {
    font-size: 1.5rem;
    font-weight: 700;
    color: #6366f1;
}

.course-tag {
    background: #6366f1;
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 500;
    position: absolute;
    top: 1rem;
    right: 1rem;
}

.course-card {
    position: relative;
}

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

/* Trust Indicators */
.trust-indicators {
    padding: 60px 20px;
    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 {
    color: #6366f1;
    margin-bottom: 1rem;
}

.trust-item h3 {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
    color: #1e293b;
}

.trust-item p {
    color: #64748b;
    font-size: 0.9rem;
}

/* Footer */
.footer {
    background: #1e293b;
    color: white;
    padding: 60px 20px 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: #f1f5f9;
}

.footer-section p {
    color: #94a3b8;
    margin-bottom: 0.5rem;
}

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

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

.footer-section ul li a {
    color: #94a3b8;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section ul li a:hover {
    color: #6366f1;
}

.footer-contact a {
    color: #94a3b8;
    text-decoration: none;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid #334155;
    color: #94a3b8;
}

/* Course Detail Page */
.course-detail {
    padding: 40px 20px;
}

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

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

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

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

.course-info h3 {
    font-size: 1.25rem;
    margin: 2rem 0 1rem;
    color: #1e293b;
}

.course-info ul {
    margin-bottom: 2rem;
}

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

.course-sidebar {
    background: #f8fafc;
    padding: 2rem;
    border-radius: 12px;
    height: fit-content;
    position: sticky;
    top: 100px;
}

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

.sidebar-price {
    font-size: 2rem;
    font-weight: 700;
    color: #6366f1;
    margin-bottom: 1.5rem;
}

.sidebar-info {
    margin-bottom: 2rem;
}

.sidebar-info div {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.sidebar-info strong {
    color: #1e293b;
}

.sidebar-info span {
    color: #64748b;
}

.instructor-info {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid #e2e8f0;
}

.instructor-info h4 {
    margin-bottom: 0.5rem;
    color: #1e293b;
}

.instructor-info p {
    font-size: 0.9rem;
    color: #64748b;
}

/* FAQ Section */
.faq-item {
    background: white;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    margin-bottom: 1rem;
    overflow: hidden;
}

.faq-question {
    width: 100%;
    text-align: left;
    padding: 1rem;
    background: none;
    border: none;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    color: #1e293b;
    transition: background-color 0.3s ease;
}

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

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

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

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

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

.form-control {
    width: 100%;
    padding: 12px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

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

.form-control.error {
    border-color: #ef4444;
}

.error-message {
    color: #ef4444;
    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: 0.5rem;
}

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

.checkbox-group label {
    margin-bottom: 0;
    font-weight: normal;
    font-size: 0.9rem;
}

/* Checkout */
.checkout-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 40px 20px;
}

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

.step {
    display: flex;
    align-items: center;
    padding: 1rem;
    color: #64748b;
}

.step.active {
    color: #6366f1;
    font-weight: 600;
}

.step-number {
    width: 30px;
    height: 30px;
    border-radius: 50%;
    background: #e2e8f0;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-right: 0.5rem;
    font-weight: 600;
}

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

.checkout-form {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
}

.order-summary {
    background: #f8fafc;
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 2rem;
}

.order-summary h3 {
    margin-bottom: 1rem;
    color: #1e293b;
}

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

.summary-total {
    display: flex;
    justify-content: space-between;
    font-size: 1.25rem;
    font-weight: 700;
    color: #1e293b;
}

.payment-methods {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    justify-content: center;
}

.payment-methods svg {
    width: 40px;
    height: 25px;
}

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

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

    .nav-toggle {
        display: flex;
    }

    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

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

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

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

    .course-sidebar {
        position: static;
    }

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

    .hero-actions {
        justify-content: center;
    }

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

@media (max-width: 480px) {
    .hero {
        padding: 40px 20px;
    }

    .features,
    .featured-courses {
        padding: 40px 20px;
    }

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

    .course-card {
        min-width: unset;
    }
}

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

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