It's cropped out in the screenshot, but if you look at Twitter html source, you'll see that there is a <style> tag that opens at the end of the line before the

It's cropped out in the screenshot, but if you look at Twitter html source, you'll see that there is a <style> tag that opens at the end of the line before the CSS. There is a <title> tag, but it's created by Javascript. You can see it with document.querySelector('title') once the page loads.