.lesson-page { padding: 40px 0 80px; }
.lesson-header { margin-bottom: 32px; }
.lesson-format-badges {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 10px;
}
.lesson-header h1 { font-size: 1.75rem; margin-top: 0; }

.lesson-player { margin-bottom: 32px; }

.lesson-media-block + .lesson-media-block {
    margin-top: 24px;
}

.video-embed {
    position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden;
    border-radius: var(--radius); background: #000;
}
.video-embed iframe {
    position: absolute; top: 0; left: 0; width: 100%; height: 100%; border: 0;
}

.video-player, .audio-player {
    width: 100%; border-radius: var(--radius); background: var(--bg-muted);
}

.lesson-content {
    background: #fff; padding: 40px; border-radius: var(--radius);
    border: 1px solid var(--border); margin-top: 24px;
}

.lesson-content h2 { font-size: 1.375rem; margin: 24px 0 12px; }
.lesson-content h3 { font-size: 1.125rem; margin: 20px 0 10px; }
.lesson-content p { margin-bottom: 16px; line-height: 1.8; }
.lesson-content ul, .lesson-content ol { margin: 0 0 16px 24px; }

.lesson-content .bac-lesson { max-width: none; }
.lesson-content .bac-lesson h1 { font-size: 1.5rem; margin-bottom: 8px; color: var(--text, #1a1a2e); }
.lesson-content .bac-lesson .lead { font-size: 1.0625rem; color: var(--text-muted, #555); margin-bottom: 28px; line-height: 1.7; }
.lesson-content .bac-lesson h2 { font-size: 1.25rem; margin-top: 32px; padding-bottom: 6px; border-bottom: 1px solid var(--border, #e5e7eb); }
.lesson-content .bac-lesson p { margin-bottom: 14px; }
.lesson-content .bac-lesson ul { margin: 0 0 18px 20px; }
.lesson-content .bac-lesson ul li { margin-bottom: 6px; line-height: 1.65; }

.lesson-content .bac-tips {
    margin-top: 36px; padding: 20px 24px;
    background: #f0f7ff; border-left: 4px solid #3b82f6;
    border-radius: 0 var(--radius, 8px) var(--radius, 8px) 0;
}
.lesson-content .bac-tips h3 { font-size: 1rem; margin: 0 0 12px; color: #1e40af; }
.lesson-content .bac-tips ul { margin: 0 0 0 18px; }
.lesson-content .bac-tips li { color: #1e3a5f; }

.lesson-content .bac-note {
    margin-top: 28px; padding: 16px 20px;
    background: var(--bg-muted, #f9fafb); border-radius: var(--radius, 8px);
    border: 1px solid var(--border, #e5e7eb);
}
.lesson-content .bac-note p { margin: 0; font-size: 0.9375rem; color: var(--text-muted, #666); }

.lesson-content .lesson-empty-notice {
    padding: 24px; text-align: center; color: var(--text-muted, #666);
    background: var(--bg-muted, #f9fafb); border-radius: var(--radius, 8px);
    border: 1px dashed var(--border, #d1d5db);
}

.lesson-actions { margin-top: 24px; }

@media (max-width: 768px) {
    .lesson-content { padding: 24px; }
}