.sidebar {
    background-color: #f8f9fa;
    border-radius: 5px;
    padding: 15px;
    margin-bottom: 20px;
}
.sidebar .nav-link {
    color: #495057;
}
.sidebar .nav-link.active {
    font-weight: bold;
}
.sidebar .nav-link:hover {
    color: #212529;
    background-color: #e9ecef;
}
.sidebar .submenu-caret {
    display: inline-block;
    transition: transform 0.3s ease;
    font-size: 0.8em;
    margin-left: 5px;
}
.sidebar .nav-link[aria-expanded="true"] .submenu-caret {
    transform: rotate(180deg);
}