if screen width less button text ... code example

Example: media query change button text

<button type="button" class="btn btn-default btn-md btn-block">
    <i class="fa fa-plus"></i>
    <span class="button-text">Add New Item</span>
</button>

@media screen and (max-width: 300px) {
    .button-text {
        display: none;
    }
}