CSS

remove button default border css

button:focus { outline: none; }

removing the unwanted border button css

button,
button:active,
button:focus {
  outline: none;
}

remove outline btn

button {
  outline: none;
}
.btn:focus {
  outline: thin dotted;
  outline: 5px auto -webkit-focus-ring-color;
  outline-offset: -2px;
}
.btn:focus {
  outline: none !important;
}

.btn:focus {
  box-shadow: none;
}