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

:root {
    --primary-color: hsl(297, 70%, 50%);
    --primary-dark: hsl(297, 70%, 40%);
    --primary-light: hsl(297, 70%, 95%);
    --secondary-color: hsl(220, 13%, 18%);
    --text-color: hsl(220, 13%, 18%);
    --text-light: hsl(220, 9%, 46%);
    --border-color: hsl(220, 13%, 91%);
    --background: hsl(0, 0%, 100%);
    --background-light: hsl(220, 13%, 98%);
    --success-color: hsl(142, 76%, 36%);
    --warning-color: hsl(38, 92%, 50%);
    --error-color: hsl(0, 84%, 60%);
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --border-radius: 0.5rem;
    --transition: all 0.3s ease;
}

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

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

/* Header & Navigation */
.header {
    background: var(--background);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 1rem;
}

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

.logo {
    height: 40px;
    width: auto;
}

.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 0;
    position: relative;
}

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--primary-color);
}

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

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

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border: 1px solid transparent;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    min-height: 44px;
}

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

.btn-primary:hover {
    background-color: var(--primary-dark);
    border-color: var(--primary-dark);
}

.btn-secondary {
    background-color: transparent;
    color: var(--text-color);
    border-color: var(--border-color);
}

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

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

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

/* Hero Section */
.hero {
    padding: 4rem 0;
    background: linear-gradient(135deg, var(--primary-light) 0%, var(--background) 100%);
}

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

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-light);
    margin-bottom: 2rem;
}

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

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

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

/* Sections */
.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
}

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

/* Features */
.features {
    padding: 4rem 0;
    background-color: var(--background-light);
}

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

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

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

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

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

.feature-card p {
    color: var(--text-light);
}

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

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}

.course-card {
    background: var(--background);
    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 {
    position: relative;
    height: 200px;
    overflow: hidden;
}

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

.course-label {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background-color: var(--primary-color);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-size: 0.875rem;
    font-weight: 500;
}

.course-content {
    padding: 1.5rem;
}

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

.course-category,
.course-difficulty {
    font-size: 0.875rem;
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-weight: 500;
}

.course-category {
    background-color: var(--primary-light);
    color: var(--primary-color);
}

.course-difficulty {
    background-color: var(--background-light);
    color: var(--text-light);
}

.course-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    line-height: 1.3;
}

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

.course-details {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.course-duration {
    color: var(--text-light);
    font-size: 0.9rem;
}

.course-price {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
}

/* Search & Filter */
.search-filter {
    padding: 2rem 0;
    background-color: var(--background-light);
}

.search-form {
    display: flex;
    gap: 1rem;
    max-width: 600px;
    margin: 0 auto;
    flex-wrap: wrap;
}

.search-input,
.filter-select {
    flex: 1;
    min-width: 200px;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    background-color: var(--background);
}

.search-input:focus,
.filter-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(147, 51, 234, 0.1);
}

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

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-color);
}

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

.form-input:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(147, 51, 234, 0.1);
}

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

/* Tables */
.table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
}

.table th,
.table td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.table th {
    background-color: var(--background-light);
    font-weight: 600;
    color: var(--text-color);
}

/* Content Sections */
.content-section {
    padding: 4rem 0;
}

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

.content-main h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.content-main h2 {
    font-size: 2rem;
    margin: 2rem 0 1rem;
    color: var(--text-color);
}

.content-main h3 {
    font-size: 1.5rem;
    margin: 1.5rem 0 0.75rem;
    color: var(--text-color);
}

.content-main p {
    margin-bottom: 1rem;
    line-height: 1.7;
    color: var(--text-light);
}

.content-main ul,
.content-main ol {
    margin: 1rem 0;
    padding-left: 2rem;
}

.content-main li {
    margin-bottom: 0.5rem;
    color: var(--text-light);
}

.content-sidebar {
    background-color: var(--background-light);
    padding: 2rem;
    border-radius: var(--border-radius);
    height: fit-content;
}

/* Course Details */
.course-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 3rem 0;
}

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

.course-info h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.course-info p {
    font-size: 1.25rem;
    opacity: 0.9;
    margin-bottom: 1.5rem;
}

.course-stats {
    display: flex;
    gap: 2rem;
    flex-wrap: wrap;
}

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

.course-stat-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
}

.course-stat-label {
    font-size: 0.9rem;
    opacity: 0.8;
}

.course-sidebar {
    background: rgba(255, 255, 255, 0.1);
    padding: 2rem;
    border-radius: var(--border-radius);
    backdrop-filter: blur(10px);
}

.course-price-display {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
}

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

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

.footer-section h4 {
    margin-bottom: 1rem;
    font-size: 1.25rem;
}

.footer-section p {
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.6;
}

.footer-links {
    list-style: none;
}

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

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: var(--transition);
}

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

.contact-info p {
    margin-bottom: 0.5rem;
    color: rgba(255, 255, 255, 0.8);
}

.contact-info a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
}

.contact-info a:hover {
    color: white;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 100%;
        left: 0;
        width: 100%;
        background: var(--background);
        flex-direction: column;
        gap: 0;
        padding: 1rem;
        box-shadow: var(--shadow-lg);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }

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

    .nav-menu li {
        width: 100%;
    }

    .nav-link {
        display: block;
        padding: 1rem;
        border-bottom: 1px solid var(--border-color);
    }

    .nav-toggle {
        display: flex;
    }

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

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

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

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

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

    .course-stats {
        justify-content: center;
    }

    .search-form {
        flex-direction: column;
    }

    .search-input,
    .filter-select {
        min-width: auto;
    }

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

@media (max-width: 480px) {
    .container {
        padding: 0 0.75rem;
    }

    .hero {
        padding: 2rem 0;
    }

    .hero-title {
        font-size: 1.75rem;
    }

    .section-title {
        font-size: 2rem;
    }

    .btn {
        padding: 0.625rem 1.25rem;
        font-size: 0.9rem;
    }

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

    .feature-card,
    .content-sidebar,
    .course-sidebar {
        padding: 1.5rem;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !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 */
*:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.btn:focus,
.nav-link:focus,
.form-input:focus,
.form-textarea:focus,
.search-input:focus,
.filter-select:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}