{%- assign gaid = site.google_analytics.id -%}
{%- if jekyll.environment == 'production' and gaid -%}
  <!-- Global site tag (gtag.js) - Google Analytics -->
  <script async src="https://www.googletagmanager.com/gtag/js?id={{ gaid }}"></script>
  <script>
    window.dataLayer = window.dataLayer || [];
    function gtag(){dataLayer.push(arguments);}
    gtag("js", new Date());

    gtag("config", "{{ gaid }}");
  </script>
{%- endif -%}