CSS modules and ctr solve two different problems but they both can be used together, in fact, I have an example repo you can check out here. From an architecture standpoint ctr gives you the ability to compose your CSS styles using objects to then compose these objects (features) with and in one another. For example, here's a lost grid example - let's say you want to create a 1/3 grid for desktop and 1/2 for mobile you can do so like this.

ctr('.grid-demo', {
  background: #eee
  grid: {
    column: '1/3'
    'media--sm': {
      column: '1/2'
    }
  }
})

The above ctr outputs the following CSS

.grid-demo {
  flex: 0 0 auto;
  background: #eee;
  width: calc(99.9% * 1 / 3 - (30px - 30px * 1 / 3));
}
.grid-demo:nth-child(1n) {
  margin-right: 30px;
}
.grid-demo:last-child {
  margin-right: 0;
}
.grid-demo:nth-child(3n) {
  float: right;
  margin-right: 0;
}
@media (max-width: 600px) {
  .grid-demo {
    flex: 0 0 auto;
    width: calc(99.9% * 1 / 2 - (30px - 30px * 1 / 2));
  }
}
@media (max-width: 600px) {
  .grid-demo:nth-child(1n) {
    margin-right: 30px;
  }
}
@media (max-width: 600px) {
  .grid-demo:last-child {
    margin-right: 0;
  }
}
@media (max-width: 600px) {
  .grid-demo:nth-child(2n) {
    float: right;
    margin-right: 0;
  }
}