/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #333;
    background: #fff;
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 1rem;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p {
    margin-bottom: 1rem;
}

a {
    color: #6366f1;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 8px;
    font-weight: 500;
    text-decoration: none;
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
}

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

.btn-primary:hover {
    background: #5856eb;
    text-decoration: none;
}

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

.btn-secondary:hover {
    background: #6366f1;
    color: white;
    text-decoration: none;
}

.btn-success {
    background: #10b981;
    color: white;
}

.btn-success:hover {
    background: #059669;
    text-decoration: none;
}

/* Header */
.header {
    background: white;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.25rem;
    font-weight: 600;
    color: #333;
    text-decoration: none;
}

.nav-list {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    color: #666;
    font-weight: 500;
    padding: 0.5rem 0;
    transition: color 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: #6366f1;
    text-decoration: none;
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background: #333;
    margin: 3px 0;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    padding: 4rem 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

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

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1.5rem;
}

.hero p {
    font-size: 1.125rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

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

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

/* Features Section */
.features {
    padding: 4rem 0;
    background: #f8fafc;
}

.features h2 {
    text-align: center;
    margin-bottom: 3rem;
    color: #1e293b;
}

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

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
}

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

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

.featured-courses h2 {
    text-align: center;
    margin-bottom: 3rem;
    color: #1e293b;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.course-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
}

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

.course-content {
    padding: 1.5rem;
}

.course-category {
    display: inline-block;
    background: #e0e7ff;
    color: #6366f1;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 1rem;
}

.course-title {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: #1e293b;
}

.course-description {
    color: #64748b;
    margin-bottom: 1rem;
    font-size: 0.875rem;
}

.course-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    font-size: 0.875rem;
    color: #64748b;
}

.course-price {
    font-size: 1.25rem;
    font-weight: 600;
    color: #059669;
    margin-bottom: 1rem;
}

/* Trust Section */
.trust-section {
    padding: 3rem 0;
    background: #f1f5f9;
}

.trust-section h2 {
    text-align: center;
    margin-bottom: 2rem;
    color: #1e293b;
}

.trust-features {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 2rem;
}

.trust-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 500;
}

.trust-icon {
    color: #10b981;
    font-weight: bold;
}

/* Footer */
.footer {
    background: #1e293b;
    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 h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: #e2e8f0;
}

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

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

.footer-section a {
    color: #cbd5e1;
}

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

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

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

.course-header {
    margin-bottom: 3rem;
}

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

.course-main {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.course-sidebar {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    height: fit-content;
    position: sticky;
    top: 100px;
}

.curriculum-list {
    list-style: none;
}

.curriculum-list li {
    padding: 0.75rem 0;
    border-bottom: 1px solid #e2e8f0;
}

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

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

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

.step {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: #e2e8f0;
    color: #64748b;
    border-radius: 20px;
    margin: 0 0.5rem;
}

.step.active {
    background: #6366f1;
    color: white;
}

.checkout-form {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: #374151;
}

.form-control {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #d1d5db;
    border-radius: 6px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-control:focus {
    outline: none;
    border-color: #6366f1;
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

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

.error-message {
    color: #ef4444;
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

.order-summary {
    background: #f8fafc;
    padding: 1.5rem;
    border-radius: 8px;
    margin-bottom: 2rem;
}

.payment-icons {
    display: flex;
    gap: 0.5rem;
    align-items: center;
    margin: 1rem 0;
}

.payment-icon {
    width: 40px;
    height: 25px;
    background: #f3f4f6;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 500;
    color: #6b7280;
}

/* Courses Page */
.courses-header {
    padding: 2rem 0;
    background: #f8fafc;
}

.courses-filters {
    background: white;
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    margin-bottom: 2rem;
}

.filters-row {
    display: grid;
    grid-template-columns: 1fr 200px 200px;
    gap: 1rem;
    align-items: end;
}

.search-box {
    position: relative;
}

.search-input {
    width: 100%;
    padding: 0.75rem 1rem 0.75rem 2.5rem;
    border: 1px solid #d1d5db;
    border-radius: 8px;
    font-size: 1rem;
}

.search-icon {
    position: absolute;
    left: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    color: #9ca3af;
}

.select-wrapper {
    position: relative;
}

.select-control {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #d1d5db;
    border-radius: 8px;
    background: white;
    font-size: 1rem;
    appearance: none;
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='m6 8 4 4 4-4'/%3e%3c/svg%3e");
    background-position: right 0.5rem center;
    background-repeat: no-repeat;
    background-size: 1.5em 1.5em;
}

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

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

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 15px;
    }
    
    .nav {
        display: none;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .course-detail-grid {
        grid-template-columns: 1fr;
    }
    
    .filters-row {
        grid-template-columns: 1fr;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .trust-features {
        justify-content: center;
        text-align: center;
    }
    
    .trust-item {
        flex-direction: column;
        gap: 0.25rem;
    }
}

@media (max-width: 480px) {
    .courses-grid {
        grid-template-columns: 1fr;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 200px;
    }
}

/* RTL Support */
[dir="rtl"] .header-content {
    direction: rtl;
}

[dir="rtl"] .nav-list {
    direction: rtl;
}

[dir="rtl"] .hero .container {
    direction: rtl;
}

[dir="rtl"] .search-icon {
    left: auto;
    right: 0.75rem;
}

[dir="rtl"] .search-input {
    padding-left: 1rem;
    padding-right: 2.5rem;
}

/* Form Validation */
.form-control.invalid {
    border-color: #ef4444;
}

.form-control.valid {
    border-color: #10b981;
}

/* Loading States */
.loading {
    opacity: 0.6;
    pointer-events: none;
}

/* Accessibility */
.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 States */
.btn:focus,
.form-control:focus,
.nav-link:focus {
    outline: 2px solid #6366f1;
    outline-offset: 2px;
}