* {
    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(220, 70%, 50%);
    --accent-color: hsl(45, 90%, 60%);
    --text-color: #333;
    --text-light: #666;
    --text-muted: #999;
    --bg-color: #fff;
    --bg-light: #f8f9fa;
    --bg-section: #f5f6f7;
    --border-color: #e1e5e9;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 20px rgba(0, 0, 0, 0.15);
    --border-radius: 8px;
    --transition: all 0.3s ease;
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
}

body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
}

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

/* Header */
.header {
    background: var(--bg-color);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav {
    padding: 1rem 0;
}

.nav .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: var(--text-color);
    font-weight: 700;
    font-size: 1.25rem;
}

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

.nav-link {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: var(--transition);
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
}

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

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

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-color);
    margin: 3px 0;
    transition: var(--transition);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    text-decoration: none;
    border-radius: var(--border-radius);
    font-weight: 600;
    text-align: center;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

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

.btn-outline {
    background: transparent;
    color: var(--text-color);
    border: 2px solid var(--border-color);
}

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

/* Hero Section */
.hero {
    padding: 4rem 0;
    background: linear-gradient(135deg, var(--bg-light) 0%, white 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 50%;
    height: 100%;
    background: url('/assets/bg-hero.svg') no-repeat center right;
    background-size: contain;
    opacity: 0.1;
    z-index: 1;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
    position: relative;
    z-index: 2;
}

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

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

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

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

/* Features Section */
.features {
    padding: 4rem 0;
    background: var(--bg-section);
}

.features h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--text-color);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.feature {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    text-align: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.feature:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.feature h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.feature p {
    color: var(--text-light);
    line-height: 1.6;
}

/* Courses Section */
.featured-courses {
    padding: 4rem 0;
    background: white;
}

.featured-courses h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--text-color);
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.course-card {
    background: white;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.course-image {
    width: 100%;
    height: 200px;
    background: var(--bg-light);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

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

.course-content {
    padding: 1.5rem;
}

.course-meta {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.course-tag {
    background: var(--primary-color);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
}

.course-difficulty {
    background: var(--bg-light);
    color: var(--text-color);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.875rem;
}

.course-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.course-title a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

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

.course-description {
    color: var(--text-light);
    margin-bottom: 1rem;
    line-height: 1.6;
}

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

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

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

.course-instructor {
    color: var(--text-light);
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

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

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

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

.form-control {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: var(--transition);
    font-family: inherit;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(168, 85, 247, 0.1);
}

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

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

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

.checkbox-group label {
    margin-bottom: 0;
    font-weight: 400;
    line-height: 1.5;
}

/* Search and Filter */
.search-filter {
    background: var(--bg-light);
    padding: 2rem 0;
    margin-bottom: 2rem;
}

.search-form {
    display: grid;
    grid-template-columns: 1fr auto auto auto;
    gap: 1rem;
    align-items: end;
}

.search-input {
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
}

.filter-select {
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    background: white;
    min-width: 150px;
}

/* Course Detail */
.course-header {
    padding: 3rem 0;
    background: var(--bg-section);
}

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

.course-info h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.course-info .course-meta {
    margin-bottom: 1.5rem;
}

.course-info .course-description {
    font-size: 1.125rem;
    margin-bottom: 2rem;
}

.course-sidebar {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    position: sticky;
    top: 100px;
}

.course-sidebar .course-price {
    font-size: 2rem;
    text-align: center;
    margin-bottom: 1.5rem;
}

.course-sidebar .btn {
    width: 100%;
    margin-bottom: 1rem;
}

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

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

.course-main h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.course-main h3 {
    font-size: 1.5rem;
    margin: 2rem 0 1rem 0;
    color: var(--text-color);
}

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

.course-main li {
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--border-color);
    position: relative;
    padding-left: 1.5rem;
}

.course-main li:before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

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

.curriculum-item h4 {
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

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

.instructor-card {
    background: var(--bg-light);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    margin-bottom: 2rem;
}

.instructor-card h4 {
    margin-bottom: 1rem;
    color: var(--text-color);
}

.faq-item {
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
}

.faq-question {
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.faq-answer {
    color: var(--text-light);
    line-height: 1.6;
}

/* Checkout */
.checkout-header {
    background: var(--bg-section);
    padding: 2rem 0;
    text-align: center;
}

.checkout-steps {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-top: 1rem;
}

.step {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    background: var(--bg-light);
    color: var(--text-muted);
}

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

.checkout-content {
    padding: 3rem 0;
}

.checkout-form {
    max-width: 600px;
    margin: 0 auto;
}

.order-summary {
    background: var(--bg-light);
    padding: 2rem;
    border-radius: var(--border-radius);
    margin-bottom: 2rem;
}

.order-item {
    display: flex;
    justify-content: space-between;
    padding: 1rem 0;
    border-bottom: 1px solid var(--border-color);
}

.order-total {
    display: flex;
    justify-content: space-between;
    padding: 1rem 0;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--text-color);
}

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

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

/* Footer */
.footer {
    background: var(--text-color);
    color: white;
    padding: 3rem 0 1rem 0;
    margin-top: 4rem;
}

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

.footer-section h4 {
    margin-bottom: 1rem;
    color: white;
}

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

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

.footer-section a {
    color: #ccc;
    text-decoration: none;
    transition: var(--transition);
}

.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;
}

.contact-info p {
    margin-bottom: 0.5rem;
    color: #ccc;
}

.footer-bottom {
    border-top: 1px solid #555;
    padding-top: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.footer-links {
    display: flex;
    gap: 1rem;
}

.footer-links a {
    color: #ccc;
    text-decoration: none;
    font-size: 0.875rem;
}

/* 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: var(--shadow);
    }

    .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 h2,
    .featured-courses h2 {
        font-size: 2rem;
    }

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

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

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

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

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

    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }

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

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

    .hero {
        padding: 2rem 0;
    }

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

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

    .btn {
        width: 100%;
    }

    .features,
    .featured-courses {
        padding: 2rem 0;
    }

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

    .course-sidebar {
        position: static;
        margin-top: 2rem;
    }
}

/* Utility Classes */
.text-center {
    text-align: center;
}

.text-left {
    text-align: left;
}

.text-right {
    text-align: right;
}

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.hidden {
    display: none;
}

.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;
}