@import "twbs-variables";
@import "twbs/bootstrap/mixins";

.turbolinks-progress-bar {
  height: 5px;
  background-color: $brand-primary;
}

@import "twbs-variables";
@import "twbs/bootstrap/mixins";

.turbolinks-progress-bar {
  height: 2px;
  background-color: $brand-primary;
}

Reduce Turbolinks progress bar height
Reduce Turbolinks progress bar height