/* Language toggle button styling */
#lang-toggle {
    padding: 5px 12px;
    margin-right: 10px;
    background: var(--theme-hover);
    border: 1px solid var(--theme-popup-border);
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.875rem;
    font-weight: 500;
    transition: all 0.2s ease;
}

#lang-toggle:hover {
    background: var(--theme-popup-bg);
    border-color: var(--links);
}

#lang-toggle:active {
    transform: scale(0.95);
}

/* Improve readability for Korean section headers in sidebar */
.chapter li.chapter-item {
    line-height: 1.6;
}

/* Style for language section headers in sidebar */
.chapter li.spacer {
    margin-top: 1rem;
    font-weight: 600;
    color: var(--sidebar-fg);
}

/* Smooth transitions for sidebar filtering */
.chapter li {
    transition: opacity 0.2s ease, max-height 0.2s ease;
}

.chapter li[style*="display: none"] {
    opacity: 0;
    max-height: 0;
    overflow: hidden;
}