nvironmental variables=] are four env variables
          that define a rectangle by the width and height from a starting point
          in the viewport. This area corresponds to the available area of the
          title bar, and allows to position dynamic Web content inside its
          bounds.
        </p>
      </section>
    </section>
    <section>
      <h2>
        Integration with CSSOM
      </h2>
      <p>
        This specification integrates with the [[cssom-view]] specification by
        pat