@media (max-width: 1023px) {
  /* Navigation */
  .nav-name,
  .nav-position {
    display: none;
  }
  .nav-center-a {
    display: inline;
    justify-items: center;
    width: 50px;
  }

  /* Background */

  .width-300 {
    width: 300px !important;
  }
  .width-640 {
    width: 640px !important;
  }

  #background {
    align-items: start;
    height: 1500px;
    display: flex;
    flex-direction: column;
    flex-wrap: wrap;
  }
  /* Certification */
  #certification {
    column-gap: 0;
  }

  .certification-div {
    display: block;
  }

  .certification-left-div {
    padding-right: 20px;
  }

  .certification-right-div {
    padding-left: 20px;
  }

  .certification-div img {
    width: 100%;
    margin-bottom: 10px;
  }

  .certification-div {
    display: block;
  }
}