body {margin: 0;padding:0;  font-family: "Montserrat", sans-serif; font-size: 12px; background: #000; color: #fff;}

// <weight>: Use a value from 100 to 900
// <uniquifier>: Use a unique and descriptive class name

.montserrat-<uniquifier> {
  font-family: "Montserrat", sans-serif;
  font-optical-sizing: auto;
  font-weight: <weight>;
  font-style: normal;
}