/* 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: #333;
    background-color: #fff;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

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

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 6px;
    font-weight: 600;
    text-align: center;
    transition: all 0.3s ease;
    border: 2px solid transparent;
    cursor: pointer;
    text-decoration: none;
}

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

.btn-primary:hover {
    background-color: #4f46e5;
    border-color: #4f46e5;
    transform: translateY(-1px);
}

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

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

.btn-outline {
    background-color: transparent;
    color: #374151;
    border-color: #d1d5db;
}

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

/* Header */
.header {
    background-color: #fff;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    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: 12px;
    font-weight: 700;
    font-size: 1.25rem;
    color: #6366f1;
}

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

.nav-link {
    font-weight: 500;
    color: #374151;
    transition: color 0.3s ease;
    padding: 8px 0;
    position: relative;
}

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: #6366f1;
}

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

.nav-toggle span {
    width: 25px;
    height: 3px;
    background-color: #374151;
    margin: 2px 0;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    padding: 80px 0;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-content h1 {
    font-size: 3rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 24px;
    color: #1f2937;
}

.hero-content p {
    font-size: 1.25rem;
    color: #6b7280;
    margin-bottom: 32px;
    line-height: 1.6;
}

.hero-actions {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.hero-image {
    text-align: center;
}

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

.features h2 {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 60px;
    color: #1f2937;
}

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

.feature-card {
    text-align: center;
    padding: 40px 20px;
    border-radius: 12px;
    background-color: #f8fafc;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

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

.feature-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 16px;
    color: #1f2937;
}

.feature-card p {
    color: #6b7280;
    line-height: 1.6;
}

/* Featured Courses Section */
.featured-courses {
    padding: 80px 0;
    background-color: #f8fafc;
}

.featured-courses h2 {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 60px;
    color: #1f2937;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 40px;
    margin-bottom: 60px;
}

.course-card {
    background-color: #fff;
    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 10px 40px rgba(0, 0, 0, 0.15);
}

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

.course-image img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.course-label {
    position: absolute;
    top: 16px;
    right: 16px;
    background-color: #6366f1;
    color: white;
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 600;
}

.course-content {
    padding: 24px;
}

.course-meta {
    display: flex;
    gap: 12px;
    margin-bottom: 16px;
}

.course-category {
    background-color: #e0e7ff;
    color: #6366f1;
    padding: 4px 12px;
    border-radius: 16px;
    font-size: 0.875rem;
    font-weight: 500;
}

.course-difficulty {
    background-color: #f3f4f6;
    color: #6b7280;
    padding: 4px 12px;
    border-radius: 16px;
    font-size: 0.875rem;
    font-weight: 500;
}

.course-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 12px;
    color: #1f2937;
}

.course-card p {
    color: #6b7280;
    margin-bottom: 20px;
    line-height: 1.6;
}

.course-details {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    padding-top: 16px;
    border-top: 1px solid #e5e7eb;
}

.course-duration {
    color: #6b7280;
    font-size: 0.875rem;
}

.course-price {
    font-size: 1.25rem;
    font-weight: 700;
    color: #6366f1;
}

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

/* CTA Section */
.cta {
    padding: 80px 0;
    background: linear-gradient(135deg, #6366f1 0%, #4f46e5 100%);
    color: white;
}

.cta .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.cta-content h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 24px;
}

.cta-content p {
    font-size: 1.25rem;
    margin-bottom: 32px;
    opacity: 0.9;
    line-height: 1.6;
}

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

.cta .btn-primary:hover {
    background-color: #f8fafc;
}

.cta-image {
    text-align: center;
}

/* Footer */
.footer {
    background-color: #1f2937;
    color: #d1d5db;
    padding: 60px 0 20px;
}

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

.footer-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 700;
    font-size: 1.25rem;
    color: #6366f1;
    margin-bottom: 16px;
}

.footer-section h4 {
    color: white;
    font-weight: 600;
    margin-bottom: 16px;
}

.footer-section ul {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.footer-section a {
    color: #d1d5db;
    transition: color 0.3s ease;
}

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

.footer-bottom {
    border-top: 1px solid #374151;
    padding-top: 20px;
    text-align: center;
    color: #9ca3af;
}

/* Search and Filter */
.search-filter {
    background-color: #fff;
    padding: 40px 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

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

.search-box {
    flex: 1;
    min-width: 300px;
}

.search-input {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

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

.filter-group {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.filter-select {
    padding: 12px 16px;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    font-size: 1rem;
    background-color: white;
    cursor: pointer;
    transition: border-color 0.3s ease;
}

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

/* Course Detail Page */
.course-header {
    background: linear-gradient(135deg, #6366f1 0%, #4f46e5 100%);
    color: white;
    padding: 60px 0;
}

.course-detail {
    padding: 60px 0;
}

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

.course-main h2 {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 24px;
    color: #1f2937;
}

.course-main h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin: 32px 0 16px;
    color: #1f2937;
}

.course-main ul {
    list-style: disc;
    padding-left: 20px;
    margin-bottom: 24px;
}

.course-main li {
    margin-bottom: 8px;
    color: #6b7280;
}

.course-sidebar {
    background-color: #f8fafc;
    padding: 40px;
    border-radius: 12px;
    height: fit-content;
    position: sticky;
    top: 100px;
}

.course-info {
    margin-bottom: 32px;
}

.course-info-item {
    display: flex;
    justify-content: space-between;
    padding: 12px 0;
    border-bottom: 1px solid #e5e7eb;
}

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

.course-info-label {
    font-weight: 600;
    color: #374151;
}

.course-info-value {
    color: #6b7280;
}

.instructor-card {
    background-color: white;
    padding: 24px;
    border-radius: 8px;
    margin-bottom: 32px;
}

.instructor-name {
    font-weight: 600;
    font-size: 1.125rem;
    margin-bottom: 8px;
    color: #1f2937;
}

.instructor-bio {
    color: #6b7280;
    font-size: 0.875rem;
    line-height: 1.5;
}

.curriculum-list {
    background-color: white;
    border-radius: 8px;
    overflow: hidden;
}

.curriculum-item {
    padding: 16px 20px;
    border-bottom: 1px solid #e5e7eb;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.lesson-number {
    background-color: #6366f1;
    color: white;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.875rem;
    font-weight: 600;
    margin-right: 12px;
}

.lesson-title {
    flex: 1;
    font-weight: 500;
    color: #374151;
}

.faq-item {
    background-color: white;
    border-radius: 8px;
    margin-bottom: 16px;
    overflow: hidden;
}

.faq-question {
    padding: 20px;
    background-color: #f8fafc;
    font-weight: 600;
    color: #1f2937;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.faq-question:hover {
    background-color: #e2e8f0;
}

.faq-answer {
    padding: 20px;
    color: #6b7280;
    line-height: 1.6;
    display: none;
}

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

/* Contact Form */
.contact-form {
    background-color: #f8fafc;
    padding: 60px 0;
}

.form-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
}

.form-group {
    margin-bottom: 24px;
}

.form-label {
    display: block;
    font-weight: 600;
    margin-bottom: 8px;
    color: #374151;
}

.form-input,
.form-textarea {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

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

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

.contact-info {
    background-color: white;
    padding: 40px;
    border-radius: 12px;
    height: fit-content;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    margin-bottom: 24px;
}

.contact-icon {
    width: 24px;
    height: 24px;
    background-color: #6366f1;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 0.875rem;
    margin-top: 2px;
}

.contact-details h4 {
    font-weight: 600;
    margin-bottom: 4px;
    color: #1f2937;
}

.contact-details p {
    color: #6b7280;
    line-height: 1.5;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: white;
        flex-direction: column;
        padding: 20px;
        box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s ease;
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-toggle {
        display: flex;
    }

    .hero .container {
        grid-template-columns: 1fr;
        gap: 40px;
        text-align: center;
    }

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

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

    .cta .container {
        grid-template-columns: 1fr;
        gap: 40px;
        text-align: center;
    }

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

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

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

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

    .filter-group {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

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

    .hero-content p {
        font-size: 1rem;
    }

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

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

    .course-sidebar {
        padding: 24px;
    }

    .btn {
        padding: 10px 20px;
        font-size: 0.875rem;
    }
}

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

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

    .hero,
    .features,
    .featured-courses,
    .cta {
        padding: 20px 0;
    }

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