@media screen and (-ms-high-contrast: active), (-ms-high-contrast: none) {  
    /* Put your IE-only styles here. Works for IE 10 & IE 11*/
    .header-search .typeahead.dropdown-menu {
        width: 100%;
    }

    .tree-nodes-container .tree-parent:last-child {
        flex-grow: 1;
    }
}