fieldset.bordesito {
  border: 1px groove #ddd !important;
  padding: 0 1.4em 1.4em 1.4em !important;
  margin: 0 0 1.5em 0 !important;
  -webkit-box-shadow:  0px 0px 0px 0px #000;
          box-shadow:  0px 0px 0px 0px #000;
}

legend.bordesito {
  width:inherit; /* Or auto */
  padding:0 10px; /* To give a bit of padding on the left and right */
  border-bottom:none;
}