@media only screen and (max-width: 768px) {

  #scroll-up-btn {
    width: 60px;
    height: 60px;
    bottom: 60px;
    right: 60px;
    font-size: 45px;
    line-height: 0px;
  }

  .footer-contacts {
    flex-flow: column;
  }

  .main-logo {
    width: 80px;
  }

  .hero-text {
    font-size: 3em;
  }

  .hero-slogan {
    top: 40%;
  }
}