.dropdown-group {
    position: relative;
    width: 100%;
}

.dropdown-submenu {
    display: none;
    width: 100%;
    background-color: rgba(248, 249, 250, 0.8);
    border-left: 2px solid #6c757d;
    /* margin-left: 1rem; */
    transition: all 0.3s ease;
}

/* Position du sous-menu sur desktop */
@media (min-width: 768px) {
    .dropdown-submenu {
        left: 100%;
        top: 0;
    }
}

/* Position du sous-menu sur mobile */
@media (max-width: 767px) {
    .dropdown-submenu {
        left: 0;
        top: 100%;
        width: 100%;
    }

    .dropdown-item.sub-item {
        padding-left: 2rem;
    }
}

.dropdown-group:hover .dropdown-submenu {
    display: block;
}

.dropdown-item {
    padding: 0.75rem 1rem;
    transition: all 0.2s ease;
    border: none;
    background: transparent;
    width: 100%;
    text-align: left;
    cursor: pointer;
    color: #495057;
    font-size: 0.95rem;
    border-radius: 4px;
    margin: 2px 0;
}

.dropdown-item:hover {
    background-color: rgba(108, 117, 125, 0.1);
    color: #212529;
}

.dropdown-item.group-header {
    position: relative;
    padding-right: 2rem;
    font-weight: 600;
    color: #212529;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.dropdown-item.group-header::after {
    content: '›';
    position: absolute;
    right: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    transition: transform 0.2s ease;
    color: #6c757d;
}

.dropdown-group:hover .dropdown-item.group-header::after {
    transform: translateY(-50%) rotate(90deg);
}

.dropdown-item.sub-item {
    padding-left: 2rem;
    font-size: 0.9rem;
    color: #6c757d;
    font-weight: 400;
}

.dropdown-item.sub-item:hover {
    background-color: rgba(108, 117, 125, 0.05);
    color: #495057;
}

.dropdown-item.active {
    background-color: rgba(13, 110, 253, 0.1);
    color: #0d6efd;
    font-weight: 500;
}

/* Style commun pour les menus déroulants */
#dropdown_sources,
#dropdown_modelisations {
    min-width: 250px;
    padding: 0.5rem 0;
    margin: 0;
    border: 1px solid rgba(0, 0, 0, 0.15);
    border-radius: 0.25rem;
    box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.175);
}

/* Amélioration de l'accessibilité tactile sur mobile */
@media (max-width: 767px) {
    .dropdown-item {
        padding: 0.85rem 1rem;
    }

    .dropdown-item.group-header {
        font-size: 1rem;
    }

    .dropdown-item.sub-item {
        font-size: 0.95rem;
    }
}