How to correctly display diacritics of the alphabet on the site - hacek (ˇ), acute (´), umlaut (¨), circumflex (^)?

Question

Fonts

Slovak. The site uses Cuprum (headings) and Fira Sans (body text) as a font pair
. Everything looks good in the design -

But on the site, some letters look like from a different font -

For example - Č, Á, etc.

How to make it look like in design? And if you change the fonts, I think it will be the same. Do I need to write down some rule or use something ready for these cases?

Answer 1

The font must support the required languages.