Mise en forme conditionnelle – @media screen

@media screen and (max-width: 640px) {
  .class {
    display:unset;
  }
}

@media screen and (min-width: 200px) and (max-width: 640px) {
   .class {
    display:unset;
  }
}

@media screen and (orientation:portrait) {
  .class {
    display:unset;
  }
}