// Change address font-size if needed document.addEventListener('DOMContentLoaded', function (evt) { var recipientAddress = document.getElementsByClassName('address row')[0].getElementsByTagName('address')[0]; var height = parseFloat(window.getComputedStyle(recipientAddress, null).getPropertyValue('height')); var fontSize = parseFloat(window.getComputedStyle(recipientAddress, null).getPropertyValue('font-size')); recipientAddress.style.fontSize = (85/height) * fontSize + 'px'; });