@media screen and (min-width: 992px) {
  .how-to-articles article {
    width: calc(25% - 38px);
    margin: 0 50px 50px 0;
  }  
  .how-to-articles article:nth-child(4n) {
    margin-right: 0;
  }
}
@media screen and (max-width: 991px) {
  .how-to-articles article {
    width: calc(50% - 10px);   
    margin-bottom: 25px; 
  }
  .how-to-articles article:nth-child(even) {
    margin-left: 10px;
    margin-right: 0;
  }
  .how-to-articles article:nth-child(odd) {
    margin-left: 0;
    margin-right: 10px;
  }
  .how-to-articles article figure {
    margin: 0;
  }
}