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

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: #6366f1;
    font-weight: bold;
    font-size: 1.2rem;
}

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

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

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

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

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

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: #333;
    margin: 2px 0;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 4rem 0;
    min-height: 70vh;
    display: flex;
    align-items: center;
}

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

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

.hero-content p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

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

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

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    text-align: center;
    transition: all 0.3s;
    border: none;
    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: 2px solid white;
}

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

.btn-outline {
    background: transparent;
    color: #6366f1;
    border: 2px solid #6366f1;
}

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

/* Sections */
section {
    padding: 4rem 0;
}

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

.features {
    background: #f8fafc;
}

.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;
}

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

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

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

.feature-card p {
    color: #666;
    line-height: 1.6;
}

/* Courses Grid */
.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, 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, box-shadow 0.3s;
    border: 1px solid #e5e7eb;
}

.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-tag {
    display: inline-block;
    background: #e0e7ff;
    color: #6366f1;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.75rem;
}

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

.course-description {
    color: #666;
    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: #666;
}

.course-price {
    font-size: 1.5rem;
    font-weight: bold;
    color: #6366f1;
    margin-bottom: 1rem;
}

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

.course-actions .btn {
    flex: 1;
    padding: 10px 16px;
}

/* Trust Section */
.trust-section {
    background: #f8fafc;
}

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

.trust-item {
    text-align: center;
    padding: 2rem;
}

.trust-icon {
    font-size: 3rem;
    color: #10b981;
    margin-bottom: 1rem;
}

.trust-item h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: #333;
}

.trust-item p {
    color: #666;
}

/* Section Footer */
.section-footer {
    text-align: center;
    margin-top: 2rem;
}

/* Course Filters */
.course-filters {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    margin-bottom: 3rem;
}

.filter-row {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 1rem;
    align-items: end;
}

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

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

.filter-group input,
.filter-group select {
    padding: 12px;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.filter-group input:focus,
.filter-group select:focus {
    outline: none;
    border-color: #6366f1;
}

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

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

.course-hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

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

.course-hero-meta span {
    background: rgba(255,255,255,0.2);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.875rem;
}

.course-purchase-card {
    background: white;
    color: #333;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

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

.course-purchase-price {
    font-size: 2rem;
    font-weight: bold;
    color: #6366f1;
    margin-bottom: 1.5rem;
}

.course-detail-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
    padding: 3rem 0;
}

.course-detail-main h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: #333;
    text-align: left;
}

.course-detail-main h3 {
    font-size: 1.5rem;
    margin: 2rem 0 1rem 0;
    color: #333;
}

.course-detail-main ul {
    list-style: none;
    padding: 0;
}

.course-detail-main li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
}

.course-detail-main li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: #10b981;
    font-weight: bold;
}

.curriculum-list {
    background: #f8fafc;
    padding: 1.5rem;
    border-radius: 8px;
}

.curriculum-list li {
    padding: 0.75rem 0;
    border-bottom: 1px solid #e5e7eb;
}

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

.instructor-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    margin-bottom: 2rem;
}

.instructor-card h3 {
    margin-bottom: 1rem;
    color: #333;
}

.faq-item {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    margin-bottom: 1rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

.faq-question {
    font-weight: bold;
    margin-bottom: 0.5rem;
    color: #333;
}

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

/* Checkout Forms */
.checkout-container {
    max-width: 800px;
    margin: 2rem auto;
    padding: 0 20px;
}

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

.step {
    display: flex;
    align-items: center;
    padding: 1rem 2rem;
    background: #f3f4f6;
    color: #6b7280;
    position: relative;
}

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

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

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

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

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

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

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

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

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

.error-message {
    color: #ef4444;
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

.success-message {
    color: #10b981;
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

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

.summary-item {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid #e5e7eb;
}

.summary-total {
    font-size: 1.25rem;
    font-weight: bold;
    color: #333;
}

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

.payment-icon {
    width: 40px;
    height: 25px;
    background: #f3f4f6;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    color: #666;
}

.checkbox-group {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    margin: 1.5rem 0;
}

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

.checkbox-group label {
    font-weight: normal;
    line-height: 1.5;
    margin-bottom: 0;
}

/* Order Success */
.success-container {
    max-width: 600px;
    margin: 3rem auto;
    padding: 0 20px;
    text-align: center;
}

.success-icon {
    font-size: 4rem;
    color: #10b981;
    margin-bottom: 1rem;
}

.success-container h1 {
    color: #10b981;
    margin-bottom: 1rem;
}

.order-details {
    background: #f8fafc;
    padding: 2rem;
    border-radius: 12px;
    margin: 2rem 0;
    text-align: left;
}

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

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

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: #f9fafb;
}

.footer-section p {
    color: #d1d5db;
    line-height: 1.6;
    margin-bottom: 0.5rem;
}

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

.footer-contact a {
    color: #d1d5db;
    text-decoration: none;
}

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

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

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

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

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

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

/* Content Pages */
.content-container {
    max-width: 800px;
    margin: 2rem auto;
    padding: 0 20px;
}

.content-container h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #333;
}

.content-container h2 {
    font-size: 2rem;
    margin: 2rem 0 1rem 0;
    color: #333;
    text-align: left;
}

.content-container h3 {
    font-size: 1.5rem;
    margin: 1.5rem 0 1rem 0;
    color: #333;
}

.content-container p {
    margin-bottom: 1rem;
    line-height: 1.7;
    color: #555;
}

.content-container ul,
.content-container ol {
    margin-bottom: 1rem;
    padding-left: 2rem;
}

.content-container li {
    margin-bottom: 0.5rem;
    line-height: 1.6;
    color: #555;
}

.contact-info {
    background: #f8fafc;
    padding: 2rem;
    border-radius: 12px;
    margin: 2rem 0;
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        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 .container {
        grid-template-columns: 1fr;
        text-align: center;
    }

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

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

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

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

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

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

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

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

    .form-row,
    .form-row-3 {
        grid-template-columns: 1fr;
    }

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

    .step {
        width: 100%;
        justify-content: center;
        margin-bottom: 0.5rem;
    }
}

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

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

    .hero-actions {
        flex-direction: column;
        width: 100%;
    }

    .btn {
        width: 100%;
    }

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

    .payment-icons {
        flex-wrap: wrap;
    }
}

/* Focus States for Accessibility */
.btn:focus,
.nav-link:focus,
input:focus,
select:focus,
textarea:focus {
    outline: 2px solid #6366f1;
    outline-offset: 2px;
}

/* Print Styles */
@media print {
    .header,
    .footer,
    .nav,
    .hero,
    .btn {
        display: none;
    }
    
    body {
        font-size: 12pt;
        line-height: 1.4;
    }
}