Bootstrap3 mobile version is very small. Why?

Question

HTML

Help! I am making a landing on bootstrap3, I made one section and decided to check how it will be on mobile. On a mobile phone, the site is displayed all skewed as if not adaptive at all. The first time I see this piyvki.simple-page.ru/. Moreover, everything is fine in the browser, even if you look through the code in the mobile version. Android phone.
What could be the problem ?

Answer 1

<meta name="viewport" content="width=device-width, initial-scale=1.0">

in head add