<!DOCTYPE html>
<style>
  p {
    color: transparent;
  }
  @media (resolution: 1dppx) {
    p {
      font-size: 1px;
    }
  }
  @media (resolution: 2dppx) {
    p {
      font-size: 2px;
    }
  }
  @media (resolution: 3dppx) {
    p {
      font-size: 3px;
    }
  }
  </style>
  <p>Test</p>