Mobile safari and 100vh - how to make it understand the height indicated in the "viewports"?

Question

css

Hello colleagues!
Please help me solve the problem:
There is a slider with a height of 100vh ( dev.imdeveloper.ru/bisness-school/). It behaves normally in all browsers and even on mobile. However! It is worth discovering it in a mobile safari - fenita la comedy! The picture moves around in its entire width (exactly 1200 * 800), and that's it, up to the hanging of the device, which is natural, with such dimensions.
QUESTION: How is it treated? Those. how to make Safari display a slide on the screen in full height and proportionally shrink the width, or what ..? I see only one way out - clearly her - the height - to register, but, again, how? After all, neither min- nor max-, and even more so as a percentage, Safari (versions 6-7) does not want to understand ... Or am I confusing something?
Please help me solve the problem: how to display the slider in full height on mobile safari: mobile and tablet.
Thank you very much in advance!!!