Add Custom CSS to Admin Area - Web Development Tips

For a quick addition of css selector(s) :

// Add Custom CSS to Admin Area
add_action('admin_head', 'awk_custom_css');

function awk_custom_css() {
  echo '<style>
    #wpfooter {
		  bottom: auto;
	  }
  </style>';
}

By adding a stylesheet with your styling to your child theme root named admin-style.css.

// Add your custom stylsheet file that is in child-theme root
add_action( 'admin_enqueue_scripts', 'awk_admin_style');
function awk_admin_style() {
  wp_enqueue_style( 'admin-style', get_stylesheet_directory_uri() . '/admin-style' );
}