:root {
    --primary: #034690;
    --secondary: #10B981;
    --dark: #1e293b;
    --gray: #64748b;
    --light: #f8fafc;
    --white: #ffffff;
    --border: #e2e8f0;
    --success: #10B981;
    --danger: #EF4444;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --radius: 12px;
}

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

body {
    font-family: 'Cairo', sans-serif;
    background: var(--light);
    color: var(--dark);
    line-height: 1.6;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.hidden {
    display: none !important;
}

/* Course Header */
.course-header {
    background: linear-gradient(135deg, var(--primary) 0%, #0056b3 100%);
    color: var(--white);
    padding: 3rem 0;
    margin-top: 5%;
}

.course-header-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 3rem;
    align-items: center;
}

.accreditation-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(255, 255, 255, 0.2);
    padding: 0.5rem 1rem;
    border-radius: 50px;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.category-badge {
    display: inline-block;
    background: var(--secondary);
    padding: 0.375rem 1rem;
    border-radius: 50px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.course-title {
    font-size: 2.25rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.3;
}

.course-description {
    font-size: 1.125rem;
    opacity: 0.9;
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.price-section {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.current-price {
    font-size: 2rem;
    font-weight: 700;
}

.original-price {
    font-size: 1.25rem;
    text-decoration: line-through;
    opacity: 0.7;
}

.discount {
    background: var(--danger);
    padding: 0.375rem 0.875rem;
    border-radius: 50px;
    font-size: 0.875rem;
    font-weight: 600;
}

.enroll-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    background: var(--white);
    color: var(--primary);
    border: none;
    border-radius: 50px;
    font-size: 1.125rem;
    font-weight: 700;
    font-family: 'Cairo', sans-serif;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
}

.enroll-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.2);
}

.course-image {
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.course-image img {
    width: 100%;
    height: auto;
    display: block;
}

/* Course Content Section */
.course-content-section {
    padding: 3rem 0;
}

.content-wrapper {
    display: grid;
    grid-template-columns: 1fr 380px;
    gap: 2rem;
}

/* Video Player */
.video-player-section {
    background: var(--white);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

.video-container {
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
    overflow: hidden;
    border-radius: var(--radius);
    margin-bottom: 1.5rem;
}

.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

/* Video Info */
.video-info {
    padding-top: 1.5rem;
    border-top: 2px solid var(--border);
}

.video-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 0.75rem;
}

.free-preview-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.375rem;
    padding: 0.375rem 0.875rem;
    background: linear-gradient(135deg, #10B981 0%, #059669 100%);
    color: var(--white);
    border-radius: 50px;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.3px;
}

.video-info h3 {
    font-size: 1.25rem;
    color: var(--dark);
    margin: 0;
}

.video-description {
    color: var(--gray);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* Locked Content */
.locked-content {
    position: relative;
    min-height: 400px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
}

.lock-overlay {
    text-align: center;
    color: white;
    padding: 40px;
}

.lock-overlay i {
    font-size: 4rem;
    margin-bottom: 20px;
    opacity: 0.9;
}

.lock-overlay h3 {
    font-size: 2rem;
    margin-bottom: 10px;
    font-weight: 700;
}

.lock-overlay p {
    font-size: 1.1rem;
    margin-bottom: 30px;
    opacity: 0.9;
    line-height: 1.6;
}

.unlock-btn {
    background: white;
    color: #667eea;
    padding: 15px 40px;
    border: none;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-family: 'Cairo', sans-serif;
    text-decoration: none;
}

.unlock-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
}

/* Curriculum Sidebar */
.curriculum-sidebar {
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    height: fit-content;
    max-height: 800px;
    overflow-y: auto;
}

.curriculum-header {
    padding: 1.5rem;
    border-bottom: 2px solid var(--border);
    position: sticky;
    top: 0;
    background: var(--white);
    z-index: 10;
}

.curriculum-header h3 {
    font-size: 1.125rem;
    color: var(--dark);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.75rem;
}

.curriculum-stats {
    display: flex;
    gap: 1rem;
    font-size: 0.875rem;
    color: var(--gray);
}

.curriculum-stats span {
    display: flex;
    align-items: center;
    gap: 0.375rem;
}

.curriculum-stats i {
    color: var(--primary);
}

/* Curriculum Section */
.curriculum-section {
    border-bottom: 1px solid var(--border);
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.5rem;
    cursor: pointer;
    background: #f1f5f9;
    transition: all 0.3s ease;
    border-bottom: 1px solid var(--border);
}

.section-header:hover {
    background: #e2e8f0;
}

.section-title-wrapper {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex: 1;
}

.section-number {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary);
    color: var(--white);
    border-radius: 50%;
    font-size: 0.875rem;
    font-weight: 700;
    flex-shrink: 0;
}

.section-title-wrapper h4 {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--dark);
    margin: 0;
    line-height: 1.4;
}

.section-meta {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.items-count {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 24px;
    height: 24px;
    padding: 0 0.5rem;
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--primary);
    background: var(--white);
    border-radius: 12px;
}

.toggle-icon {
    color: var(--gray);
    transition: transform 0.3s ease;
    font-size: 0.875rem;
}

.curriculum-section.active .toggle-icon {
    transform: rotate(180deg);
}

.section-items {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
}

.curriculum-section.active .section-items {
    max-height: 3000px;
}

/* Curriculum Item */
.curriculum-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.875rem 1.5rem;
    transition: all 0.3s ease;
    border-bottom: 1px solid #f1f5f9;
    background: var(--white);
}

.curriculum-item:hover {
    background: #f8fafc;
}

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

.item-number {
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--light);
    color: var(--gray);
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 700;
    flex-shrink: 0;
}

.curriculum-item .item-icon {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #e0f2fe;
    border-radius: 8px;
    flex-shrink: 0;
}

.curriculum-item .item-icon i {
    font-size: 1rem;
    color: var(--primary);
}

.curriculum-item.video .item-icon {
    background: #e0f2fe;
}

.curriculum-item.multiple_choice .item-icon,
.curriculum-item.true_false .item-icon {
    background: #fef3c7;
}

.curriculum-item.multiple_choice .item-icon i,
.curriculum-item.true_false .item-icon i {
    color: #f59e0b;
}

.curriculum-item .item-info {
    flex: 1;
    min-width: 0;
}

.curriculum-item .item-title {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--dark);
    margin-bottom: 0.25rem;
    line-height: 1.4;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.curriculum-item .item-duration {
    display: flex;
    align-items: center;
    gap: 0.375rem;
    font-size: 0.75rem;
    color: var(--gray);
}

.curriculum-item .item-duration i {
    font-size: 0.75rem;
}

.curriculum-item .item-status {
    flex-shrink: 0;
}

.curriculum-item .item-status i {
    color: #cbd5e0;
    font-size: 1rem;
}

/* Free Item Styling */
.curriculum-item.free-item {
    background: #f0fdf4;
    border-right: 3px solid var(--secondary);
}

.curriculum-item.free-item .item-icon {
    background: #d1fae5;
}

.curriculum-item.free-item .item-icon i {
    color: var(--secondary);
}

.free-badge {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.625rem;
    background: var(--secondary);
    color: var(--white);
    border-radius: 50px;
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.5px;
}

/* Course Tabs Section */
.course-tabs-section {
    padding: 3rem 0;
}

.tabs-header {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.tab-btn {
    padding: 0.875rem 1.5rem;
    background: var(--white);
    border: 2px solid var(--border);
    border-radius: var(--radius);
    color: var(--dark);
    font-size: 1rem;
    font-weight: 600;
    font-family: 'Cairo', sans-serif;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

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

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

.tabs-content {
    background: var(--white);
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

.tab-content h3 {
    font-size: 1.5rem;
    color: var(--dark);
    margin-bottom: 1.5rem;
}

/* Objective Box */
.objective-box {
    display: flex;
    gap: 1.5rem;
    padding: 1.5rem;
    background: var(--light);
    border-radius: var(--radius);
    border-right: 4px solid var(--primary);
}

.objective-box i {
    font-size: 2rem;
    color: var(--primary);
    flex-shrink: 0;
}

.objective-box p {
    font-size: 1.125rem;
    line-height: 1.7;
    color: var(--dark);
}

/* Objectives List */
.objectives-list {
    display: grid;
    gap: 1rem;
}

.objective-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: var(--light);
    border-radius: var(--radius);
}

.objective-item i {
    color: var(--success);
    font-size: 1.25rem;
    flex-shrink: 0;
}

.objective-item span {
    font-size: 1rem;
    color: var(--dark);
}

/* Program Modules */
.program-modules {
    display: grid;
    gap: 1.5rem;
}

.module {
    padding: 1.5rem;
    background: var(--light);
    border-radius: var(--radius);
    border-right: 4px solid var(--primary);
}

.module h4 {
    font-size: 1.125rem;
    color: var(--dark);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.module h4 i {
    color: var(--primary);
}

.module ul {
    list-style: none;
    padding-right: 1.5rem;
}

.module li {
    padding: 0.5rem 0;
    color: var(--gray);
    position: relative;
}

.module li::before {
    content: '•';
    position: absolute;
    right: -1.5rem;
    color: var(--primary);
    font-weight: bold;
}

/* Instructor Card */
.instructor-card {
    display: flex;
    gap: 1.5rem;
    padding: 1.5rem;
    background: var(--light);
    border-radius: var(--radius);
}

.instructor-avatar {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    object-fit: cover;
    flex-shrink: 0;
}

.instructor-info h4 {
    font-size: 1.5rem;
    color: var(--dark);
    margin-bottom: 0.5rem;
}

.instructor-info p {
    color: var(--gray);
    margin-bottom: 1rem;
}

.instructor-bio {
    line-height: 1.7;
}

.instructor-stats {
    display: flex;
    gap: 1.5rem;
}

.instructor-stats span {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--gray);
    font-size: 0.95rem;
}

.instructor-stats i {
    color: var(--primary);
}

/* Attachments */
.attachments-list {
    display: grid;
    gap: 1rem;
}

.attachment-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: var(--light);
    border-radius: var(--radius);
}

.locked-attachment {
    opacity: 0.7;
}

.attachment-icon {
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--white);
    border-radius: var(--radius);
    flex-shrink: 0;
}

.attachment-icon i {
    font-size: 1.5rem;
    color: var(--danger);
}

.attachment-info {
    flex: 1;
}

.attachment-info h5 {
    font-size: 1rem;
    color: var(--dark);
    margin-bottom: 0.25rem;
}

.attachment-info span {
    font-size: 0.875rem;
    color: var(--gray);
}

.locked-badge {
    display: flex;
    align-items: center;
    gap: 0.375rem;
    padding: 0.375rem 0.75rem;
    background: #fee2e2;
    color: #dc2626;
    border-radius: 50px;
    font-size: 0.75rem;
    font-weight: 600;
}

.locked-badge i {
    font-size: 0.75rem;
}

.unlock-attachments-notice {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem;
    background: #eff6ff;
    border: 1px solid #bfdbfe;
    border-radius: var(--radius);
    margin-top: 1rem;
}

.unlock-attachments-notice i {
    color: var(--primary);
    font-size: 1.25rem;
    flex-shrink: 0;
}

.unlock-attachments-notice p {
    font-size: 0.875rem;
    color: var(--dark);
    margin: 0;
    line-height: 1.5;
}

.no-content {
    text-align: center;
    padding: 2rem;
    color: var(--gray);
    font-style: italic;
}

/* Responsive */
@media (max-width: 1024px) {
    .course-header-content {
        grid-template-columns: 1fr;
    }
    
    .content-wrapper {
        grid-template-columns: 1fr;
    }
    
    .curriculum-sidebar {
        max-height: 600px;
    }
}

@media (max-width: 768px) {
    .course-title {
        font-size: 1.75rem;
    }
    
    .tabs-header {
        flex-direction: column;
    }
    
    .tab-btn {
        width: 100%;
        justify-content: center;
    }
}