Double Frame

.btn-double-frame {
  display: inline-block;
  padding: 12px 26px;
  border: 4px double #cbd5e1;
  border-radius: 8px;
  background: transparent;
  color: #cbd5e1;
  font-family: inherit;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.03em;
  cursor: pointer;
  transition: border-color 0.2s ease, color 0.2s ease;
}
.btn-double-frame:hover {
  border-color: #ffffff;
  color: #ffffff;
}
.btn-double-frame:active {
  border-color: #94a3b8;
}