#left_column,#central_column, #right_column{
  float:left;
}
@media (max-width: 1160px){
  .right-column {
    display: none;
    visibility: hidden;
  }
}
@media (max-width: 1023px){
  .left-column {
    display:none;
    visibility: hidden;
  }
}
#foot {
  clear:left;
}


.visible_mobile{
  display:none;
}
.visible_pc{
  display:block;
}
.visible_both{
  display:block;
}
@media (max-width : 700px){
  .visible_mobile {
    display: block;
  }
  .visible_pc {
    display: none;
  }
}
#page .logged_off, #page .logged_on{
  display:none;
}