just-the-docs/_includes/head_nav.html

{%- comment -%}
  Include as: {%- include head_nav.html -%}
  Depends on: site.color_scheme.
  Results in: HTML for a page-specific style element.
  Includes:
    css/activation.scss.liquid.
  Overwrites:
    activation, test_scss, scss, css, index, count.
  Should not be cached, because css/activation.scss.liquid depends on page.
{%- endcomment -%}

{% capture activation %}
  {% include css/activation.scss.liquid %}
{%- endcapture -%}

{% capture test_scss %}
  @import "./support/support";
  @import "./color_schemes/light";
  {{ activation }}
{%- endcapture -%}

{%- capture scss -%}
  @import "./support/support";
  @import "./custom/setup";
  {% if site.color_scheme and site.color_scheme != "nil" -%}
    {%- assign color_scheme = site.color_scheme -%}
  {%- else -%}
    {%- assign color_scheme = "light" -%}
  {%- endif %}
  @import "./color_schemes/light";
  {% unless color_scheme == "light" or color_scheme == "auto" %}
  @import "./color_schemes/{{ color_scheme }}";
  {% endunless %}
  {{ activation }}
{%- endcapture -%}

{%- comment -%}
  Convert to CSS, then remove the color_scheme import rules to avoid duplication.
  The value of count is page-dependent, but independent of custom color schemes.
{%- endcomment -%}
{%- assign count = test_scss  | scssify | split: ".site-nav" | size -%}
{%- unless count == 1 %}
{%- assign index = 1 | minus: count -%}
{%- assign css = scss | scssify | split: ".site-nav" | slice: index, count | join: ".site-nav" -%}
<style type="text/css">
{{ css | prepend: ".site-nav" }}
</style>
{%- endunless %}