link.css

/**
 * @file
 * Styles for Link module.
 */
.link-field-column {
  display: inline-block;
  width: 50%;
}

.link-field-column .form-text {
  width: 95%;
}
@media only screen and (max-width: 500px) {
  .link-field-column {
    width: auto;
  }
  .link-field-column .form-text {
    width: 100%;
  }
}