Oxygenados Com

                  :root {
  --borderColor: #03a9f3;
}

.border-efect-especial {
  position: relative;
  width: 140px;
  height: 64px;
  margin: auto;
  border: 1px solid #03a9f3;
  cursor: pointer;
}
.border-efect-especial::before, .border-efect-especial::after {
  content: "";
  position: absolute;
  width: 20px;
  height: 20px;
  transition: 0.3s ease-in-out;
}
.border-efect-especial::before {
  top: -5px;
  left: -5px;
  border-top: 1px solid var(--borderColor);
  border-left: 1px solid var(--borderColor);
}
.border-efect-especial::after {
  right: -5px;
  bottom: -5px;
  border-bottom: 1px solid var(--borderColor);
  border-right: 1px solid var(--borderColor);
}
.border-efect-especial:hover::before, .border-efect-especial:hover::after {
  width: calc(100% + 9px);
  height: calc(100% + 9px);
}