How can I change the inspector-style sheet of the verification tool?

I am creating a site with WordPress.I'm an amateur.

If you look at what you want to change in the verification tool, you can see that the element style is
The file name is inspector-stylesheet.

That's the excerpt from the php, but
You are trying to change the size of this character.

How can this be done?

functions.php

 function twpp_change_excerpt_length($length){
    return70; 
  }
add_filter('excerpt_length', 'twpp_change_excerpt_length',999);

archive.php

<div class="blog-item-excerpt">
    <?php echo mb_substr(get_the_excerpt(), 0,50).'[...]';?>
        </div>
                <?php//end?> to display excerpts    

calling in .