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

:root {
    --primary-color: hsl(297, 70%, 50%);
    --primary-light: hsl(297, 70%, 60%);
    --primary-dark: hsl(297, 70%, 40%);
    --secondary-color: hsl(210, 70%, 50%);
    --accent-color: hsl(45, 90%, 55%);
    --text-primary: hsl(210, 15%, 15%);
    --text-secondary: hsl(210, 10%, 45%);
    --text-muted: hsl(210, 8%, 65%);
    --bg-primary: hsl(0, 0%, 100%);
    --bg-secondary: hsl(210, 20%, 98%);
    --bg-tertiary: hsl(210, 15%, 95%);
    --border-color: hsl(210, 15%, 90%);
    --border-light: hsl(210, 10%, 95%);
    --shadow-sm: 0 1px 3px hsla(210, 15%, 15%, 0.1);
    --shadow-md: 0 4px 12px hsla(210, 15%, 15%, 0.15);
    --shadow-lg: 0 8px 32px hsla(210, 15%, 15%, 0.2);
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --transition: all 0.2s ease;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    background: var(--bg-primary);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 100;
}

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

.nav-brand {
    display: flex;
    align-items: center;
}

.brand-link {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: var(--text-primary);
}

.brand-logo {
    width: 40px;
    height: 40px;
    margin-right: 12px;
}

.brand-text {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

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

.nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    transition: var(--transition);
    padding: 0.5rem 0;
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary-color);
    border-radius: 1px;
}

.nav-mobile-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    padding: 4px;
}

.nav-mobile-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    margin: 3px 0;
    transition: var(--transition);
    border-radius: 2px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    border: 2px solid transparent;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    min-height: 48px;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

.btn-secondary {
    background: var(--secondary-color);
    color: white;
}

.btn-secondary:hover {
    background: hsl(210, 70%, 40%);
    transform: translateY(-1px);
}

.btn-outline {
    background: transparent;
    color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-outline:hover {
    background: var(--primary-color);
    color: white;
}

.btn:focus {
    outline: 3px solid hsla(297, 70%, 50%, 0.3);
    outline-offset: 2px;
}

/* Hero Section */
.hero {
    position: relative;
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
    padding: 80px 0;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    right: 0;
    width: 50%;
    height: 100%;
    opacity: 0.1;
    z-index: 1;
}

.hero-bg-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.hero-content {
    position: relative;
    z-index: 2;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-text h1 {
    font-size: 3rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.hero-text p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.6;
}

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

/* Sections */
.featured-courses {
    padding: 80px 0;
    background: var(--bg-primary);
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.section-header p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

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

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

.course-card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    transition: var(--transition);
    border: 1px solid var(--border-light);
}

.course-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.course-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    background: var(--bg-secondary);
}

.course-content {
    padding: 1.5rem;
}

.course-header {
    margin-bottom: 1rem;
}

.course-category {
    display: inline-block;
    background: var(--primary-color);
    color: white;
    padding: 4px 12px;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.course-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

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

.course-title a:hover {
    color: var(--primary-color);
}

.course-description {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    line-height: 1.5;
}

.course-meta {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
    font-size: 0.875rem;
    color: var(--text-muted);
}

.course-meta span {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

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

.course-price {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.course-instructor {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Trust Section */
.trust-section {
    padding: 80px 0;
    background: var(--bg-secondary);
}

.trust-items {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 3rem;
}

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

.trust-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    background: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.trust-item h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.trust-item p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Footer */
.footer {
    background: var(--text-primary);
    color: white;
    padding: 60px 0 20px;
    position: relative;
}

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

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
    position: relative;
    z-index: 1;
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.footer-logo {
    width: 50px;
    height: 50px;
}

.footer-brand h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-light);
}

.footer-brand p {
    color: hsla(0, 0%, 100%, 0.8);
    line-height: 1.6;
}

.footer-section h4 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: white;
}

.footer-links {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.footer-links a {
    color: hsla(0, 0%, 100%, 0.8);
    text-decoration: none;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--primary-light);
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.contact-info p {
    color: hsla(0, 0%, 100%, 0.8);
    margin: 0;
}

.contact-info a {
    color: hsla(0, 0%, 100%, 0.8);
    text-decoration: none;
    transition: var(--transition);
}

.contact-info a:hover {
    color: var(--primary-light);
}

.footer-bottom {
    border-top: 1px solid hsla(0, 0%, 100%, 0.2);
    padding-top: 2rem;
    text-align: center;
    position: relative;
    z-index: 1;
}

.footer-bottom p {
    color: hsla(0, 0%, 100%, 0.6);
    margin: 0;
}

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

.course-detail-header {
    background: var(--bg-secondary);
    padding: 3rem 0;
    margin-bottom: 3rem;
}

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

.course-detail-main h2 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.course-detail-main h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin: 2rem 0 1rem;
    color: var(--text-primary);
}

.course-detail-main ul {
    margin: 1rem 0;
    padding-left: 1.5rem;
}

.course-detail-main li {
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.course-sidebar {
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: var(--radius-lg);
    height: fit-content;
    position: sticky;
    top: 100px;
}

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

.course-purchase .course-price {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.course-info {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-bottom: 2rem;
}

.course-info-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-light);
}

.course-info-item:last-child {
    border-bottom: none;
}

.course-info-label {
    font-weight: 600;
    color: var(--text-primary);
}

.course-info-value {
    color: var(--text-secondary);
}

/* Curriculum */
.curriculum-list {
    list-style: none;
    padding: 0;
}

.curriculum-item {
    background: var(--bg-secondary);
    margin-bottom: 0.5rem;
    padding: 1rem;
    border-radius: var(--radius-md);
    border-left: 4px solid var(--primary-color);
}

.curriculum-item h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.curriculum-item p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin: 0;
}

/* FAQ */
.faq-list {
    margin-top: 2rem;
}

.faq-item {
    border: 1px solid var(--border-light);
    border-radius: var(--radius-md);
    margin-bottom: 1rem;
    overflow: hidden;
}

.faq-question {
    background: var(--bg-secondary);
    padding: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
}

.faq-question:hover {
    background: var(--bg-tertiary);
}

.faq-answer {
    padding: 0 1.5rem 1.5rem;
    color: var(--text-secondary);
    line-height: 1.6;
    display: none;
}

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

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

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--text-primary);
}

.form-input {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: var(--transition);
    background: var(--bg-primary);
}

.form-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px hsla(297, 70%, 50%, 0.1);
}

.form-input.error {
    border-color: hsl(0, 70%, 50%);
}

.form-error {
    color: hsl(0, 70%, 50%);
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

.form-textarea {
    resize: vertical;
    min-height: 120px;
}

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

.form-checkbox input {
    margin-top: 0.25rem;
}

.form-checkbox label {
    font-size: 0.875rem;
    line-height: 1.5;
    color: var(--text-secondary);
}

.form-checkbox a {
    color: var(--primary-color);
    text-decoration: none;
}

.form-checkbox a:hover {
    text-decoration: underline;
}

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

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

.checkout-steps {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 3rem;
}

.checkout-step {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-muted);
}

.checkout-step.active {
    color: var(--primary-color);
}

.checkout-step-number {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 0.875rem;
}

.checkout-step.active .checkout-step-number {
    background: var(--primary-color);
    color: white;
}

.checkout-form {
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: var(--radius-lg);
    margin-bottom: 2rem;
}

.checkout-summary {
    background: var(--bg-primary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 2rem;
    margin-bottom: 2rem;
}

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

.summary-item:last-child {
    border-bottom: none;
    font-weight: 700;
    font-size: 1.125rem;
    color: var(--primary-color);
}

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

.payment-icon {
    width: 40px;
    height: 24px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.security-info {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-top: 1rem;
}

/* Course Catalog */
.catalog-header {
    background: var(--bg-secondary);
    padding: 3rem 0;
    margin-bottom: 3rem;
}

.catalog-filters {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.filter-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.filter-select {
    padding: 8px 12px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-primary);
    font-size: 0.875rem;
    min-width: 150px;
}

.search-box {
    flex: 1;
    max-width: 400px;
}

.search-input {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
}

.catalog-results {
    margin-bottom: 2rem;
}

.results-info {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--bg-primary);
        box-shadow: var(--shadow-md);
        flex-direction: column;
        padding: 1rem;
        gap: 0;
    }

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

    .nav-mobile-toggle {
        display: flex;
    }

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

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

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

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

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

    .course-sidebar {
        position: static;
    }

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

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

    .checkout-steps {
        gap: 1rem;
    }

    .checkout-step span {
        display: none;
    }

    .catalog-filters {
        flex-direction: column;
    }

    .filter-select,
    .search-input {
        width: 100%;
    }
}

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

    .hero {
        padding: 40px 0;
    }

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

    .section-header h2 {
        font-size: 2rem;
    }

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

    .course-card {
        margin: 0 10px;
    }

    .checkout-container {
        padding: 1rem 15px;
    }

    .checkout-form,
    .checkout-summary {
        padding: 1.5rem;
    }
}