postcss-px-to-viewport/example/main.css

.class {
  margin: -10px .5vh;
  padding: 5vmin 9.5px;
  border: 3px solid black;
  font-size: 14px;
  line-height: 20px;
}
.class2 {
  font-size: 20px;
  line-height: 30px;
}
@media (min-width: 750px) {
  .class3 {
    font-size: 16px;
    line-height: 22px;
  }
}

/*
.class {
    font-size: 16px;
}
*/