responsive.js

(function () {
  var scale = 1 / window.devicePixelRatio;
  document.querySelector('meta[name=viewport]').setAttribute('content', 'width=device-width,initial-scale='+scale+',maximum-scale='+scale+',minimum-scale='+scale+',user-scalable=no');
  var rangingRem = document.createElement('div');
  rangingRem.style.cssText = 'width:1rem;';
  document.head.appendChild(rangingRem);
  var defaultFontSize = parseFloat(getComputedStyle(rangingRem).getPropertyValue('width'), 10);
  document.head.removeChild(rangingRem);
  var uiWidth = parseInt(document.querySelector('meta[itemprop=uw]').getAttribute('content'), 10);
  document.documentElement.style.fontSize = document.documentElement.clientWidth * 100 / uiWidth / defaultFontSize * 100 + '%';
})();