How to change font style of whole community

I want to change font style of my community
and also all post of user should be in card view

Something like this:

body {
    font-family: 'Comic Sans MS', cursive;
}

PS: adjust font name 😛

Exgossi and also all post of user should be in card view

This will likely require an extension as this feature isn't part of Flarum's core.

This also sounds a bit extreme. Maybe you wanted the post count in the user card ?

Exgossi and also all post of user should be in card view

Perhaps the Material Design Theme would work for that?

also want

You can change the forum CSS through the admin panel, in the Appearance tab. There is a Custom CSS feature there.

please help i have tried but no results please provide css with example:

clarkwinkelmann what type of fonts can we choose? is possible to use a custom font?

vaultboy Flarum doesn't embed any custom font by itself, but nothing prevents you from adding one.

You could include it via the custom header, via extend.php and a HEAD content extender, or via the Flagrow Fonts extension.