dynamic-usage.html

<style>
  .button-red {
    color: red;
  }
</style>

dynamic-usage.jade

import Style from './style.ess?dynamic'

/**
 * Dynamically compiled
 */

Style(color='red')

static-usage.css

.button-red {
  color: red;
}

static-usage.ess

import Style from './style.ess'

/**
 * Statically compiled
 */

Style(color='red')

style.ess

.button-(props.color)
  color: =props.color