/* ============================================================
   LESSON PLAYER STYLES (LEARNING INTERFACE)
   ============================================================ */

.lesson-player-container {
    background-color: #f8fafc;
    min-height: calc(100vh - 72px);
}

.lesson-player-grid {
    display: grid;
    grid-template-columns: 1fr 360px;
    align-items: start;
    max-width: 100%;
}

/* Left Panel: Main content */
.lesson-main-content {
    padding: var(--space-xl);
}

.video-player-wrapper {
    position: relative;
    width: 100%;
    aspect-ratio: 16 / 9;
    background-color: #000;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    margin-bottom: var(--space-lg);
}

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

.lesson-nav-bar {
    background-color: var(--bg-white);
    padding: 16px var(--space-lg);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    margin-bottom: var(--space-xl);
    border: 1px solid var(--border-light);
}

.lesson-details-card {
    background-color: var(--bg-white);
    padding: var(--space-2xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
}

/* Right Panel: Curriculum sidebar */
.lesson-sidebar {
    background-color: var(--bg-white);
    border-left: 1px solid var(--border-color);
    height: calc(100vh - 72px);
    position: sticky;
    top: 72px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.lesson-sidebar .sidebar-header {
    padding: var(--space-lg);
    border-bottom: 1px solid var(--border-color);
}

.lesson-sidebar .sidebar-header h3 a {
    font-size: var(--text-xs);
    font-weight: 700;
    text-transform: uppercase;
    color: var(--text-muted);
}

.lesson-sidebar .sidebar-lessons-list {
    flex: 1;
    overflow-y: auto;
    padding-bottom: var(--space-2xl);
}

.sidebar-section-title {
    background-color: var(--bg-input);
    padding: 10px var(--space-lg);
    font-size: var(--text-xs);
    font-weight: 700;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

.sidebar-lesson-item {
    border-bottom: 1px solid var(--border-light);
    transition: background-color var(--transition-fast);
}

.sidebar-lesson-item:hover:not(.locked) {
    background-color: #fafbfc;
}

.sidebar-lesson-item.active {
    background-color: var(--accent-light);
}

.sidebar-lesson-item.active a {
    color: var(--accent) !important;
}

.sidebar-lesson-item.locked {
    opacity: 0.7;
    background-color: #fcfcfc;
}

.sidebar-lesson-item a, 
.sidebar-lesson-item .flex-between {
    padding: 14px var(--space-lg);
    font-size: var(--text-xs);
    font-weight: 600;
    color: var(--text-primary);
    display: flex;
    align-items: center;
}

.sidebar-lesson-item .lesson-title {
    line-height: 1.4;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 220px;
}

.sidebar-lesson-item .lesson-time {
    color: var(--text-muted);
    font-weight: 500;
    font-size: 10px;
}

/* Responsive adjust */
@media (max-width: 992px) {
    .lesson-player-grid {
        grid-template-columns: 1fr;
    }
    
    .lesson-sidebar {
        position: relative;
        top: 0;
        height: 450px;
        border-left: none;
        border-top: 1px solid var(--border-color);
    }
    
    .lesson-main-content {
        padding: var(--space-md);
    }
}