#box {
  background-color: red;
}
  
@media (max-width: 992px) { 
  #box {
    background-color: blue;
  }
};

@media (max-width: 768px) { 
  #box {
    background-color: green;
  }
};

@media (max-width: 576px) { 
  #box {
    background-color: blueviolet;
  }
};