@media screen and (max-width: 640px) and (orientation: portrait) {
.column1 {
  float: left;
  width: 100%;
  padding: 10px;
}
.column2 {
  float: left;
  width: 100%;
  padding: 10px;
}
.column3 {
  float: left;
  width: 100%;
}
.column4 {
  float: left;
  width: 100%;
}   
    
    
}