.tn-btn-arrow .tn-atom:after {
    content: ''; 
    position: relative;
    top: 1px;
    width: 20px;
    height:20px;
    margin-left: 7px;
    display:inline-block;
    background-repeat: no-repeat;
    background-size: cover;
    background-image:  url(https://static.tildacdn.com/tild3234-3038-4861-b835-343338323937/f-arrow-2.svg);
    transition: all 0.3s ease;
}