Making a classic page responsive using <meta name="viewport" content="width=device-width, initial-sc

Hi,

I have a set up where a news article is submitted from a power app form.  This article is then copied into a classic sharepoint page.  This page needs to be made responsive as it is part of a bigger Intranet using sharepoint online, which is responsive. 

Is there some code which can be included in the classic page?  Or is there anyway I can incorporate

<meta name="viewport" content="width=device-width, initial-scale=1"> into the classic page?

Many thanks