I was able to solve the problem. It was just as I expected: meta tag viewport should be before stylesheet so the html should look like that:
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no"/>
<link href="/CMSPages/GetResource.ashx?stylesheetname=ICantTellYouTheName" type="text/css" rel="stylesheet"/>
The problem is: how to put meta tag before stylesheet tag, while stylesheet is added automatically by Kentico before all meta tags which are added in master page. And I solved problem by editing PortalTemplate.aspx file (I added there meta tag before title).
But I don't like it. Consider that I have two sites running under one Kentico instance. Both of them are using PortalTemplate.aspx. What If I'd like to have other metadata on first one and other on second. Can I add meta data before style sheet without changing Portal Template.aspx?