<html style="font-size: 50px;">
<style>
body {
    font-size: 50%;
}
</style>
<body contenteditable="true">
All the text here should be the same size.&nbsp;
<script>
document.execCommand("SelectAll");
document.execCommand("Copy");
window.getSelection().modify("move", "forward", "character");
document.execCommand("Paste");
</script>
</body>