How to change vue-multiselect component box with ccs?

In vuejs(2.6.14) I use vue-multiselect component

<multiselect
    v-model="selected_city_id"
    :options="citiesSelectionArray"
    label="label"
    track-by="code"
    class="form-control"
    placeholder="Выберите город"
    selectLabel	=""
    selectedLabel=""
    deselectLabel=""
    :multiple="false"
>
</multiselect>

and I need to show selection items area bordered from 4 sides, like : Screenshot by Lightshot
Modifying styles of vue-multiselect component in my scss file with code

.multiselect__content-wrapper {
    margin: 0 !important;
    padding: 0 !important;


    -webkit-box-shadow:  7px 7px 7px 7px #c5c5c5;
    -moz-box-shadow: 7px 7px 7px 7px #c5c5c5;
    box-shadow: 7px 7px 7px 7px #c5c5c5;
    display: inline-block;
}

I managed I look it like : Screenshot by Lightshot

Can I alter boxes I need with css styling?

Thanks in advance!