How to make the blog entry boxes smaller vertically

The default way of WordPress does not work for the Japanese language but I have added the following code to manage it.

function buddyboss_custom_short_excerpt($excerpt){
    $limit = 300;

    if (strlen($excerpt) > $limit) {
        return substr($excerpt, 0, strpos($excerpt, ' ', $limit));
    }

    return $excerpt;
}

add_filter('the_excerpt', 'buddyboss_custom_short_excerpt');