@danicalc If you are using AMP in transitional
or standard
mode you can add the below to your themes style.css file. By using the [amp]
selector it will ensure the rules only apply to AMP URLs.
html[amp] #page {
background-color: red;
}
If you are using AMP in reader
mode your themes style.css does not apply, so you will need to add the below to your active themes functions.php file.
add_action( 'amp_post_template_css', function() {
?>
/* Put Custom CSS here */
<?php
} );