VSCode Syntax Highlighting CSS/PHP mixed

I have a file style.php that contains css primarily and php in some areas. Syntax highlighting is completely broken in this scenario.

<?php
    header("Content-type: text/css");
?>
:root{
    --some-css-variable: <?php echo get_theme_mod("some_variable")?>
}

body{
    background: pink;
    .
    .
    .

}

I've tried a bunch of extensions and ancient forum post suggestions, but I cannot get vscode to recognise the php for what it is and the CSS for what it is.
I'm perfectly fine having to manually choose a language mode of (for instance) php+css, comment annotate that the outside is css, or whatever else - since it's not obvious that the non-php part is css. But I've found zero solutions, to what seems like a fairly common scenario.

Does anyone know how to fix this?

Add style tags around your style definitions and remove them on output. You can do it like following:

<?php if (false) { ?>
    <style>
<?php } ?>
    body {
        background: pink;
    }
<?php if (false) { ?>
    </style>
<?php } ?>

It's not that nice but it works on my own VSCode.