#sign_in_form, #sign_up_form {
  width: 656px;
  height: 600px;
  margin: 0 auto;
  background: transparent url('') no-repeat scroll center top;
}

#sign_in_box {
  width: 270px;
  float:right;
  margin: 30px -150px 0 0;
  padding: 10px;
  border: 2px solid #ccc;
  background-color: #fff;
}

#sign_in_info_box {
  width: 270px;
  float:left;
  margin: 430px 0 0 -150px;
  padding: 10px;
  border: 2px solid #ccc;
  background-color: #fff;
}