Change the widths in Barceloneta

Plone Support Customizing Plone
4

In the barceloneta rules, it uses a 12 grid system:

  <xsl:if test="//aside[@id='portal-column-one'] and //aside[@id='portal-column-two']">col-xs-12 col-sm-6</xsl:if>
  <xsl:if test="//aside[@id='portal-column-two'] and not(//aside[@id='portal-column-one'])">col-xs-12 col-sm-9</xsl:if>
  <xsl:if test="//aside[@id='portal-column-one'] and not(//aside[@id='portal-column-two'])">col-xs-12 col-sm-9</xsl:if>
  <xsl:if test="not(//aside[@id='portal-column-one']) and not(//aside[@id='portal-column-two'])">col-xs-12 col-sm-12</xsl:if>

So: you can change the 6 and 9 (just remember, it must 'add up to 12'

This means you will also change the

div class="col-xs-6 col-sm-3 sidebar-offcanvas"

Another options is the removed those classes all together, and for example use CSS flex or 'float'.