Mainly for lower version browsers
<!-- --> is annotation tag for html. A higher version of the browser will recognize that the <style> tag is a style sheet.
And ignore the html comment tag inside, it will parse it.
Some browsers with lower versions do not recognize the <style> tag, and will display the content of the style sheet on the page.
So add annotation tags, even if the lower version of the browser does not recognize the <style> tag,
The content inside will not be displayed on the page.