Fixed.
I used code:
<div class="panel callout radius">
<?php echo get_avatar( get_the_author_meta( 'user_email' ), '96' ); ?>
<div class="right">
<a href="https://twitter.com/<?php the_author_meta( 'twitter' ); ?>" target="_blank"><i class="fi-social-twitter size-24"></i></a>
<a href="<?php the_author_meta( 'facebook' ); ?>" target="_blank"><i class="fi-social-facebook size-24"></i></a>
<a href="mailto:<?php the_author_meta( 'email' ); ?>"><i class="fi-mail size-24"></i></a>
Then I found out this function could only be used in single blog page (single.php). So I followed official guide and called a curauth like:
<?php get_header();
global $curauth;
$curauth = (isset($_GET['author_name'])) ? get_user_by('slug', $author_name) : get_userdata(intval($author));
?>
Then it worked now. Thanks.