* {
    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: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: #6366f1;
    font-weight: 700;
    font-size: 1.25rem;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 30px;
    align-items: center;
}

.nav-link {
    text-decoration: none;
    color: #64748b;
    font-weight: 500;
    transition: color 0.3s ease;
    padding: 5px 0;
    position: relative;
}

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 2px;
    background: #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;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
    min-height: 44px;
}

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

.btn-primary:hover {
    background: #5855eb;
    transform: translateY(-2px);
}

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

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

.btn-outline {
    background: transparent;
    color: #6366f1;
    border: 1px solid #6366f1;
    padding: 8px 16px;
    font-size: 0.875rem;
}

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

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 120px 0 80px;
    position: relative;
    overflow: hidden;
    margin-top: 70px;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    opacity: 0.1;
    z-index: 1;
}

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

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero p {
    font-size: 1.25rem;
    margin-bottom: 40px;
    opacity: 0.9;
    line-height: 1.6;
}

.hero-actions {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

/* Features Section */
.features {
    padding: 80px 0;
    background: #f8fafc;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 40px;
}

.feature-card {
    background: white;
    padding: 40px 30px;
    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 {
    font-size: 3rem;
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 15px;
    color: #1e293b;
}

.feature-card p {
    color: #64748b;
    line-height: 1.6;
}

/* Featured Courses Section */
.featured-courses {
    padding: 80px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 15px;
    color: #1e293b;
}

.section-header p {
    font-size: 1.125rem;
    color: #64748b;
    max-width: 600px;
    margin: 0 auto;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    margin-bottom: 50px;
}

.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, box-shadow 0.3s ease;
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.12);
}

.course-image {
    position: relative;
    height: 200px;
    overflow: hidden;
}

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

.course-badge {
    position: absolute;
    top: 15px;
    right: 15px;
    background: #6366f1;
    color: white;
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
}

.course-content {
    padding: 25px;
}

.course-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
    font-size: 0.875rem;
}

.course-category {
    background: #e0e7ff;
    color: #6366f1;
    padding: 4px 12px;
    border-radius: 12px;
    font-weight: 600;
}

.course-duration {
    color: #64748b;
    font-weight: 500;
}

.course-title {
    margin-bottom: 15px;
}

.course-title a {
    text-decoration: none;
    color: #1e293b;
    font-size: 1.25rem;
    font-weight: 700;
    line-height: 1.4;
}

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

.course-description {
    color: #64748b;
    line-height: 1.6;
    margin-bottom: 20px;
}

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

.course-price {
    font-size: 1.5rem;
    font-weight: 800;
    color: #6366f1;
}

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

/* Trust Section */
.trust-section {
    padding: 80px 0;
    background: #f8fafc;
}

.trust-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
}

.trust-item {
    text-align: center;
    padding: 30px 20px;
}

.trust-icon {
    font-size: 3rem;
    margin-bottom: 20px;
}

.trust-item h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 15px;
    color: #1e293b;
}

.trust-item p {
    color: #64748b;
    line-height: 1.6;
}

/* Search and Filter */
.search-filter {
    background: white;
    padding: 30px 0;
    border-bottom: 1px solid #e2e8f0;
    margin-top: 70px;
}

.search-filter-content {
    display: flex;
    gap: 20px;
    align-items: center;
    flex-wrap: wrap;
}

.search-box {
    flex: 1;
    min-width: 250px;
    position: relative;
}

.search-box input {
    width: 100%;
    padding: 12px 45px 12px 15px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.search-box input:focus {
    outline: none;
    border-color: #6366f1;
}

.search-icon {
    position: absolute;
    right: 15px;
    top: 50%;
    transform: translateY(-50%);
    color: #64748b;
}

.filter-select {
    padding: 12px 15px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 1rem;
    background: white;
    cursor: pointer;
    transition: border-color 0.3s ease;
}

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

/* Course Detail Page */
.course-detail {
    margin-top: 70px;
    padding: 40px 0;
}

.course-header {
    background: #f8fafc;
    padding: 60px 0;
    margin-bottom: 60px;
}

.course-header-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 60px;
    align-items: center;
}

.course-info h1 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 20px;
    color: #1e293b;
}

.course-info p {
    font-size: 1.125rem;
    color: #64748b;
    line-height: 1.6;
    margin-bottom: 30px;
}

.course-meta-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.meta-item {
    text-align: center;
    padding: 15px;
    background: white;
    border-radius: 8px;
}

.meta-item strong {
    display: block;
    color: #6366f1;
    font-size: 1.125rem;
    margin-bottom: 5px;
}

.meta-item span {
    color: #64748b;
    font-size: 0.875rem;
}

.course-sidebar {
    background: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    height: fit-content;
}

.course-image-detail {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 8px;
    margin-bottom: 20px;
}

.price-section {
    text-align: center;
    margin-bottom: 25px;
}

.price {
    font-size: 2rem;
    font-weight: 800;
    color: #6366f1;
    margin-bottom: 10px;
}

.course-sections {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 60px;
}

.course-content-main {
    space-y: 40px;
}

.content-section {
    margin-bottom: 40px;
}

.content-section h2 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 20px;
    color: #1e293b;
}

.content-section ul {
    list-style: none;
    padding: 0;
}

.content-section li {
    padding: 8px 0;
    padding-left: 25px;
    position: relative;
    color: #64748b;
    line-height: 1.6;
}

.content-section li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: #10b981;
    font-weight: bold;
}

.curriculum-list {
    background: #f8fafc;
    border-radius: 8px;
    padding: 20px;
}

.curriculum-item {
    padding: 15px 0;
    border-bottom: 1px solid #e2e8f0;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.curriculum-item strong {
    color: #1e293b;
}

.curriculum-item span {
    color: #64748b;
    font-size: 0.875rem;
}

.instructor-info {
    background: #f8fafc;
    padding: 25px;
    border-radius: 8px;
    margin-bottom: 30px;
}

.instructor-info h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: #1e293b;
}

.instructor-info p {
    color: #64748b;
    line-height: 1.6;
}

.faq-item {
    background: #f8fafc;
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 15px;
}

.faq-item h4 {
    font-weight: 600;
    margin-bottom: 10px;
    color: #1e293b;
}

.faq-item p {
    color: #64748b;
    line-height: 1.6;
}

/* Contact Form */
.contact-form {
    background: white;
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    margin: 40px 0;
}

.form-group {
    margin-bottom: 25px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #1e293b;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

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

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

/* Footer */
.footer {
    background: #1e293b;
    color: white;
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section h4 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: 20px;
    color: white;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 15px;
    font-weight: 700;
    font-size: 1.25rem;
}

.footer-section p {
    color: #94a3b8;
    line-height: 1.6;
    margin-bottom: 15px;
}

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

.footer-section ul li {
    margin-bottom: 10px;
}

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

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

.footer-bottom {
    border-top: 1px solid #334155;
    padding-top: 30px;
    text-align: center;
}

.footer-bottom p {
    color: #94a3b8;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 20px;
        box-shadow: 0 4px 20px rgba(0,0,0,0.1);
        gap: 15px;
    }

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

    .nav-toggle {
        display: flex;
    }

    .hero h1 {
        font-size: 2.5rem;
    }

    .hero p {
        font-size: 1.125rem;
    }

    .hero-actions {
        flex-direction: column;
        align-items: center;
    }

    .hero-actions .btn {
        width: 100%;
        max-width: 300px;
    }

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

    .course-header-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .course-sections {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .search-filter-content {
        flex-direction: column;
        align-items: stretch;
    }

    .search-box {
        min-width: auto;
    }
}

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

    .hero {
        padding: 100px 0 60px;
    }

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

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

    .features,
    .featured-courses,
    .trust-section {
        padding: 60px 0;
    }

    .contact-form {
        padding: 30px 20px;
    }

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

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

/* Hidden content for screen readers */
.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;
}