Step 1: Create Your CSS File
You can place the CSS file wherever you’d like; I’ve chosen to place the CSS file within my theme. My admin CSS file looks like:
.wp-admin .comment pre { background: pink; /* they forgot the language! */ padding: 6px 10px; font-size: 16px; border: 1px solid #ccc; } .wp-admin .comment pre[class] { background: #fff; /* language (likely) there */ }
The CSS above makes
tags more visible. It also will make any PRE element without a class more apparent, teling me I need to fix it by adding the language as a className. Step 2: Add Your CSS to WordPress Admin in functions.php WordPress uses an add_action type of admin_enqueue_scripts for adding stylesheets anywhere within WordPress:// Update CSS within in Admin function admin_style() { wp_enqueue_style('admin-styles', get_template_directory_uri().'/admin.css'); } add_action('admin_enqueue_scripts', 'admin_style');get_template_directory_uri provides the path to your current theme, you simply need to add the filename to the end of the path.
https://davidwalsh.name/add-custom-css-wordpress-admin By David Walsh on October 7, 2015