(functionflexible (window, document) { var docEl = document.documentElement var dpr = window.devicePixelRatio || 1
// adjust body font size functionsetBodyFontSize () { if (document.body) { document.body.style.fontSize = (12 * dpr) + 'px' } else { document.addEventListener('DOMContentLoaded', setBodyFontSize) } } setBodyFontSize();
// set 1rem = viewWidth / 10 functionsetRemUnit () { var rem = docEl.clientWidth / 10 docEl.style.fontSize = rem + 'px' }
setRemUnit()
// reset rem unit on page resize window.addEventListener('resize', setRemUnit) window.addEventListener('pageshow', function (e) { if (e.persisted) { setRemUnit() } })
// detect 0.5px supports if (dpr >= 2) { var fakeBody = document.createElement('body') var testElement = document.createElement('div') testElement.style.border = '.5px solid transparent' fakeBody.appendChild(testElement) docEl.appendChild(fakeBody) if (testElement.offsetHeight === 1) { docEl.classList.add('hairlines') } docEl.removeChild(fakeBody) } }(window, document))