Overriding global theme in Ionic v4

I’m trying to override some of the styles to change the entire theme in my v4 app. Basically it boils down to wanting to do this:

$card-ios-border-radius: 0;
$card-ios-box-shadow: none;

However, the changes aren’t making their way into the theme. The documentation says to just edit the src/theme/variables.scss file but even in the other demos I’m looking at (ionic-super) the default is to import the CSS and not the SCSS files. This would lead me to believe that no amount of changing will make a difference.

So, is changing SCSS variables supported? If so, what’s the recommended way to handle this?
If it isn’t supported, then what’s the recommended way to override the base theme like this?

Well, I ended up doing this:

.md, .ios {
    ion-card {
        border-radius: 0;
        box-shadow: none;

And this appears to work. Is this the “recommended” path?