/* 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: #334155;
    background-color: #ffffff;
}

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

/* Header and Navigation */
.header {
    background: #ffffff;
    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 1rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: #1e293b;
    font-weight: 700;
    font-size: 1.25rem;
}

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

.nav-link {
    text-decoration: none;
    color: #64748b;
    font-weight: 500;
    transition: color 0.3s ease;
    padding: 0.5rem 0;
    border-bottom: 2px solid transparent;
}

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

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

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: #334155;
    margin: 3px 0;
    transition: 0.3s;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    text-align: center;
    transition: all 0.3s ease;
    border: 2px solid transparent;
    cursor: pointer;
    font-size: 1rem;
}

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

.btn-primary:hover {
    background: #4f46e5;
    border-color: #4f46e5;
    transform: translateY(-2px);
}

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

.btn-secondary:hover {
    background: #6366f1;
    color: white;
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    color: #334155;
    border-color: #cbd5e1;
}

.btn-outline:hover {
    background: #f1f5f9;
    border-color: #94a3b8;
}

.btn-success {
    background: #10b981;
    color: white;
    border-color: #10b981;
}

.btn-success:hover {
    background: #059669;
    border-color: #059669;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 4rem 0;
    min-height: 600px;
    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: 700;
    line-height: 1.2;
    margin-bottom: 1.5rem;
}

.hero-content 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;
}

/* Features Section */
.features {
    padding: 5rem 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(300px, 1fr));
    gap: 2rem;
}

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

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

.feature-icon {
    margin-bottom: 1.5rem;
}

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

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

/* Featured Courses Section */
.featured-courses {
    padding: 5rem 0;
}

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

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

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

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

.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 {
    height: 200px;
    background: #f1f5f9;
    display: flex;
    align-items: center;
    justify-content: center;
}

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

.course-content {
    padding: 1.5rem;
}

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

.course-category {
    background: #e0e7ff;
    color: #6366f1;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-weight: 500;
}

.course-difficulty {
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-weight: 500;
}

.difficulty-beginner {
    background: #dcfce7;
    color: #16a34a;
}

.difficulty-intermediate {
    background: #fef3c7;
    color: #d97706;
}

.difficulty-advanced {
    background: #fee2e2;
    color: #dc2626;
}

.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;
    line-height: 1.5;
}

.course-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid #e2e8f0;
}

.course-price {
    font-size: 1.25rem;
    font-weight: 700;
    color: #059669;
}

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

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

.trust-section h2 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 2rem;
    color: #1e293b;
}

.trust-features {
    display: flex;
    justify-content: center;
    gap: 3rem;
    flex-wrap: wrap;
}

.trust-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: #10b981;
    font-weight: 600;
}

/* Course Detail Styles */
.course-detail {
    padding: 2rem 0;
}

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

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

.course-main h2 {
    color: #1e293b;
    margin-bottom: 1.5rem;
    font-size: 1.75rem;
}

.course-main h3 {
    color: #374151;
    margin-bottom: 1rem;
    font-size: 1.25rem;
}

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

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

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

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

.course-purchase .course-price {
    font-size: 2rem;
    color: #059669;
    margin-bottom: 1rem;
}

.course-details-list {
    list-style: none;
    padding: 0;
    margin: 1.5rem 0;
}

.course-details-list li {
    display: flex;
    justify-content: space-between;
    padding: 0.5rem 0;
    border-bottom: 1px solid #e2e8f0;
}

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

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

.instructor-name {
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 0.5rem;
}

.instructor-bio {
    color: #64748b;
    font-size: 0.875rem;
}

/* Courses Page */
.courses-header {
    background: #f8fafc;
    padding: 3rem 0;
    text-align: center;
}

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

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

.filters-container {
    display: flex;
    gap: 2rem;
    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-group select,
.filter-group input {
    padding: 0.5rem;
    border: 1px solid #d1d5db;
    border-radius: 6px;
    font-size: 0.875rem;
}

.courses-content {
    padding: 2rem 0;
}

.courses-results {
    margin-bottom: 2rem;
    color: #64748b;
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: #374151;
}

.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: #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-success {
    color: #059669;
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

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

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

.checkbox-group label {
    margin: 0;
    font-weight: normal;
    cursor: pointer;
}

/* Checkout Styles */
.checkout-header {
    background: #f8fafc;
    padding: 2rem 0;
    text-align: center;
}

.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: 20px;
    background: #e2e8f0;
    color: #64748b;
}

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

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

.checkout-content {
    padding: 2rem 0;
}

.checkout-grid {
    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);
}

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

.summary-item {
    display: flex;
    justify-content: space-between;
    padding: 0.75rem 0;
    border-bottom: 1px solid #e2e8f0;
}

.summary-item:last-child {
    border-bottom: none;
    font-weight: 600;
    font-size: 1.125rem;
}

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

.payment-icon {
    padding: 0.5rem;
    border: 1px solid #d1d5db;
    border-radius: 6px;
    background: white;
}

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

.faq-question {
    width: 100%;
    padding: 1.5rem;
    background: none;
    border: none;
    text-align: left;
    font-size: 1.125rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.faq-answer {
    padding: 0 1.5rem 1.5rem;
    color: #64748b;
    display: none;
}

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

.faq-toggle {
    transition: transform 0.3s ease;
}

.faq-toggle.active {
    transform: rotate(180deg);
}

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

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

.footer-section h4 {
    margin-bottom: 1rem;
    font-size: 1.125rem;
}

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

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

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

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

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

.footer-contact {
    margin-top: 1rem;
}

.footer-contact p {
    margin-bottom: 0.5rem;
    color: #cbd5e1;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid #374151;
    color: #94a3b8;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: white;
        box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
        padding: 1rem;
    }

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

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

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

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

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

    .filters-container {
        flex-direction: column;
        align-items: stretch;
    }

    .trust-features {
        flex-direction: column;
        align-items: center;
        gap: 1.5rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 0.5rem;
    }

    .hero {
        padding: 2rem 0;
    }

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

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

    .btn {
        width: 100%;
    }

    .course-card {
        margin: 0 0.5rem;
    }
}

/* Print Styles */
@media print {
    .header,
    .footer,
    .btn {
        display: none;
    }

    body {
        font-size: 12pt;
        line-height: 1.4;
    }

    .container {
        max-width: none;
        padding: 0;
    }
}

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

/* High contrast mode support */
@media (prefers-contrast: high) {
    .btn {
        border-width: 2px;
    }
    
    .course-card {
        border: 1px solid #000;
    }
}