#toc-nav {
    position: fixed;
    top: 100px;
    right: 10px;
    width: var(--toc-width);
    height: 520px; 
    background-color: var(--toc-bg-color);
    border: 1px solid var(--toc-border-color);
    border-radius: 8px;
    padding: 10px 0px 10px 0px; 
    box-shadow: 0 5px 20px var(--toc-shadow-color);
    max-height: calc(100vh - 120px); 
    overflow-y: auto;
    z-index: 1000;
    font-size: 12px;
    line-height: normal; 
    transition: opacity 0.3s ease-in-out; 
}

#toc-nav ul {
    list-style-type: none;
    padding: 0;
    margin: 0;
}

#toc-nav ul li a {
    display: block;
    text-decoration: none;
    color: var(--toc-link-color);
    padding: 8px 10px 8px 15px; 
    font-size: 1em; 
    line-height: 1.5; 
    transition: background-color 0.2s ease, color 0.2s ease, border-left-color 0.2s ease, padding-left 0.2s ease;
    border-left: 4px solid transparent;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

#toc-nav ul li a .page-num { 
    float: right;
    font-size: 0.9em;
    color: var(--secondary-color);
    margin-left: 5px;
}

#toc-nav ul li a:hover {
    background-color: var(--toc-link-hover-bg);
    color: var(--toc-link-hover-color);
    padding-left: 19px; 
}

#toc-nav ul li a.active {
    color: var(--toc-link-active-color);
    font-weight: 600;
    background-color: var(--toc-link-active-bg);
    border-left-color: var(--toc-link-active-border);
    padding-left: 19px; 
}

#toc-nav ul li a.active .page-num {
    color: var(--toc-link-active-color); 
}



#toc-nav::-webkit-scrollbar {
    width: 6px;
}
#toc-nav::-webkit-scrollbar-track {
    background: var(--toc-scrollbar-track-bg);
    border-radius: 3px;
}
#toc-nav::-webkit-scrollbar-thumb {
    background: var(--toc-scrollbar-thumb-bg);
    border-radius: 3px;
}
#toc-nav::-webkit-scrollbar-thumb:hover {
    background: var(--toc-scrollbar-thumb-hover-bg);
}

@media (max-width: 720px) {
    #toc-nav {                
        /* display: none; */
        right: 0px;
        width: 27px;
        overflow: auto;
    }

    #toc-nav ul {
        min-width: 100px;
    }

    #toc-nav ul li a {
        padding: 8px 0px 8px 0px;
    }
}