mention new variable in our docs

mdo · XhmikosR · commit cd4dc92dd8ac · 2019-08-27T11:10:56.000+03:00
diff --git a/site/content/docs/4.3/content/reboot.md b/site/content/docs/4.3/content/reboot.md
@@ -23,7 +23,7 @@ Here are our guidelines and reasons for choosing what to override in Reboot:
 The `<html>` and `<body>` elements are updated to provide better page-wide defaults. More specifically:
 
 - The `box-sizing` is globally set on every element—including `*::before` and `*::after`, to `border-box`. This ensures that the declared width of element is never exceeded due to padding or border.
-  - No base `font-size` is declared on the `<html>`, but `16px` is assumed (the browser default). `font-size: 1rem` is applied on the `<body>` for easy responsive type-scaling via media queries while respecting user preferences and ensuring a more accessible approach.
+  - No base `font-size` is declared on the `<html>`, but `16px` is assumed (the browser default). `font-size: 1rem` is applied on the `<body>` for easy responsive type-scaling via media queries while respecting user preferences and ensuring a more accessible approach. This browser default can be overridden by modifying the `$font-size-root` variable.
 - The `<body>` also sets a global `font-family`, `font-weight`, `line-height`, and `color`. This is inherited later by some form elements to prevent font inconsistencies.
 - For safety, the `<body>` has a declared `background-color`, defaulting to `#fff`.
 
