Overriding components.css

I have successfully created a subtheme and customized some colors and other things in styles.css in the subtheme. However, I can't seem to override css that is coming from d8w3css/css/custom/components.css.

Specifically, the "Submitted by..." content aligning on the right is not looking good to me on small screens with the poster's image turned off.
I want it to align left, so I am trying to turn off the float:left on the node title (among other things).

.node > .node__title {
  float: left;
}

Line 338 in components.css, if that matters.

Putting this in styles.css does not work. The code does not appear to be used at all when the page renders.

.node > .node__title {
  float: none;
}

I have tried a variety of selectors, but without success.

Also tried: copying components.css into the subtheme /css/custom/ folder. The file seems to be ignored.

Any tips on how to do this correctly would be appreciated. (This is my first venture into Drupal 8 themes, though I've been customizing D7/D6 themes for years.)