Neo Concave

.btn-neo-concave {
  display: inline-block;
  padding: 13px 28px;
  border: none;
  border-radius: 14px;
  background: linear-gradient(145deg, #cbd0d8, #f0f5fc);
  color: #4a5568;
  font-family: inherit;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  box-shadow: 8px 8px 16px #bec3cf, -8px -8px 16px #ffffff;
  transition: box-shadow 0.2s ease;
}
.btn-neo-concave:hover {
  box-shadow: 5px 5px 12px #bec3cf, -5px -5px 12px #ffffff;
}
.btn-neo-concave:active {
  background: linear-gradient(145deg, #f0f5fc, #cbd0d8);
  box-shadow: inset 4px 4px 8px #bec3cf, inset -4px -4px 8px #ffffff;
}