Docs: consistent usage of CSS sections (#38219)

Co-authored-by: Mark Otto <markd.otto@gmail.com>

site/content/docs/5.3/helpers/focus-ring.md

@@ -45,13 +45,13 @@ By default, there is no `--bs-focus-ring-x`, `--bs-focus-ring-y`, or `--bs-focus
 </a>
 {{< /example >}}
 
-### Sass
+### Sass variables
 
 Customize the focus ring Sass variables to modify all usage of the focus ring styles across your Bootstrap-powered project.
 
 {{< scss-docs name="focus-ring-variables" file="scss/_variables.scss" >}}
 
-### Utilities
+### Sass utilities API
 
 In addition to `.focus-ring`, we have several `.focus-ring-*` utilities to modify the helper class defaults. Modify the color with any of our [theme colors]({{< docsref "/customize/color#theme-colors" >}}). Note that the light and dark variants may not be visible on all background colors given current color mode support.
 

site/content/docs/5.3/helpers/icon-link.md

@@ -70,13 +70,13 @@ Customize the color by overriding the `--bs-link-*` CSS variable:
 </a>
 {{< /example >}}
 
-### Sass
+### Sass variables
 
 Customize the icon link Sass variables to modify all icon link styles across your Bootstrap-powered project.
 
 {{< scss-docs name="icon-link-variables" file="scss/_variables.scss" >}}
 
-### Utilities
+### Sass utilities API
 
 Modify icon links with any of [our link utilities]({{< docsref "/utilities/link/" >}}) for modifying underline color and offset.
 

site/content/docs/5.3/helpers/ratio.md

@@ -74,7 +74,7 @@ This CSS variable makes it easy to modify the aspect ratio across breakpoints. T
 {{< /example >}}
 
 
-## Sass map
+## Sass maps
 
 Within `_variables.scss`, you can change the aspect ratios you want to use. Here's our default `$ratio-aspect-ratios` map. Modify the map as you like and recompile your Sass to put them to use.