style.css

/**
*
* These styles fix the menu on the site so the drop-down caret is bigger & more clearly separate from the list-item text
*/

:root {

    --caret-url: url(caret.png);
    --caret-right-url: url(caret-right.png);
    --caret-down-url: url(caret-down.png);

}

@media (max-width: 1500px) {
    .dropdown-toggle .caret {
            margin:0px !important;
            border: none !important;
            border-left: 1px solid #D9534F !important;
            width: 15px !important;
            height: 100% !important;
            right: 0 !important;
            top: 0 !important;
            padding-left: 30px !important;
            background: var(--caret-url) !important;
            background-position: center !important;
            background-size: contain !important;
            background-repeat: no-repeat !important;
    }
    li.menu-item li.menu-item .caret {
        margin-right: -15px !important; 
    }
}

details {
    margin-left:4px;
    margin-bottom: 8px;
}

details > summary {
    margin-left: -4px;

    padding: 8px;
    list-style: triangle !important;

    border:none;
    border-left: 1px solid #D9534F;
}

details > details {
    margin-left: 8px;
}

details > details > summary {
    margin-left: -8px;
    border-left: 1px solid white;
    margin-top:8px;
}
details > details > details {
    margin-left: 12px;
}
details > details > details summary {
    margin-left: -12px;
    border-left: 1px solid #D9534F;
}

/* details > summary::before { */
  /* content: "\200B"; */
/* } */
details > summary::marker, /* Latest Chrome, Edge, Firefox */ 
details > summary::-webkit-details-marker /* Safari */ {
  display: block !important;
}

details > summary {
    list-style: none;
}
details > summary::before {
    margin-left:2px;
    margin-right:4px;
    content: var(--caret-right-url);
}
details[open] > summary::before {
    content: var(--caret-down-url);
    margin-left:-2px;
}