.l-footer-nav__sns-logos {
  display: flex;
 flex-direction: row;
  justify-content: flex-end;
  margin-top: 30px;
}
.l-footer-nav__sns-logos li {
  margin-left: 15px
}
.l-footer-nav__sns-logos img {
  width: auto;
  height: 1em;
}
.l-footer-nav__sns-logos li:first-child {
  margin-left: 0;
} 
@media only screen and (max-width: 768px) {
  .l-footer-nav__sns-logos {
    justify-content: center;
  }
}