jetfx

.event {
  width: 300px;
  height: 100px;
  
  &__caption {
    color: blue;
  }

  &__description {
    color: green;
  }
}

@media screen and (max-width: 768px) {
    .event {
        &__caption {
            color: red;
        }
    }
}

.event {
  width: 300px;
  height: 100px;
  
  &__caption {
    color: blue;
    
    @media screen and (max-width: 768px) {
      color: red;
    }
  }

  &__description {
    color: green;
  }
}