/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-track {
    background: transparent;
}
::-webkit-scrollbar-thumb {
    background: #cbd5e1;
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: #94a3b8;
}

/* Typography for Markdown Content */
.prose {
    color: #334155;
    line-height: 1.8;
}

.prose h1 {
    font-size: 2.25rem;
    font-weight: 800;
    color: #1e293b;
    margin-top: 2rem;
    margin-bottom: 1.5rem;
    border-bottom: 2px solid #e2e8f0;
    padding-bottom: 0.5rem;
}

.prose h2 {
    font-size: 1.5rem;
    font-weight: 700;
    color: #334155;
    margin-top: 2rem;
    margin-bottom: 1rem;
    border-left: 4px solid #6366f1; /* Indigo accent */
    padding-left: 1rem;
    background: #f8fafc;
    padding-top: 0.5rem;
    padding-bottom: 0.5rem;
}

.prose h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
}

.prose p {
    margin-bottom: 1.25rem;
    white-space: pre-line; /* Helps preserve intended formatting if MD parsing misses some */
}

/* Lists - Critical for Vocabulary */
.prose ul, .prose ol {
    margin-bottom: 1.25rem;
    padding-left: 1.5rem;
}

.prose ul {
    list-style-type: disc;
}

.prose ol {
    list-style-type: decimal;
}

.prose li {
    margin-bottom: 0.5rem;
}

/* Vocabulary List Specifics - Often lists in these files are dense */
.prose li p {
    margin-bottom: 0;
}

.prose strong {
    color: #1e293b;
    font-weight: 600;
}

.prose blockquote {
    border-left: 4px solid #cbd5e1;
    padding-left: 1rem;
    font-style: italic;
    color: #64748b;
    margin: 1.5rem 0;
}

/* Mobile Tweaks */
@media (max-width: 768px) {
    .prose h1 { font-size: 1.75rem; }
    .prose h2 { font-size: 1.25rem; }
}

/* Active State for Sidebar Buttons */
.lesson-btn.active {
    background-color: #e0e7ff; /* Indigo 100 */
    color: #4338ca; /* Indigo 700 */
    border-left-color: #4338ca;
}