Your form looks good @kubus0212.
Your CSS looks good though I’d suggest having your media query all together at the bottom of the page rather than having it scattered. Makes it easier for anyone reading your code. And will be easier for you to read when you come back to it a year later.
Your form looks fine on iOS Chrome. That’s what I’m on.
An aside, codepen provides validators for HTML, CSS and JS. Click on the down arrow in the upper right of each section and then click on the respective ‘Analyze’ link.
The one for CSS is good. Use it, there’s a duplicate you should be aware of.
The one for HTML misses things which is why I recommend the W3C validator