html,
body {
  height: 100%;
}
@Size: 28px;

@media screen and (max-width: 767px) {
  html {
    font-size: (504 / @Size); //18px
  }
}
@media screen and (min-width: 768px) {
  html {
    font-size: (560 / @Size);
  }
}
@media screen and (min-width: 970px) {
  html {
    font-size: (672 / @Size);
  }
}
@media screen and (min-width: 1200px) {
  html {
    font-size: (784 / @Size); //28px
  }
}
