scss: bring light/dark accordion icon color handling to parity

The light themed accordion icon is controlled by a set of two variables:
- `$accordion-icon-color`
- `$accordion-icon-active-color`

The dark themed accordion icon did not have this level of control
available and instead would always use `$primary-text-emphasis-dark`.

Replicate the behaviour to permit individual control over the colours to
match the behaviour for the light themed form.

diff --git a/scss/_variables-dark.scss b/scss/_variables-dark.scss
index 10ae120de9cd9454159f7028a55061de46594571..ddc8ba31da3b608c2baf0f3b1c035af1cdbf0125 100644 (file)
--- a/scss/_variables-dark.scss
+++ b/scss/_variables-dark.scss
@@ -77,6 +77,9 @@ $form-invalid-border-color-dark:    $red-300 !default;
 // Accordion
 //
 
-$accordion-button-icon-dark:         url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='#{$primary-text-emphasis-dark}'><path fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708.708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/></svg>") !default;
-$accordion-button-active-icon-dark:  url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='#{$primary-text-emphasis-dark}'><path fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708.708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/></svg>") !default;
+$accordion-icon-color-dark:         $primary-text-emphasis-dark !default;
+$accordion-icon-active-color-dark:  $primary-text-emphasis-dark !default;
+
+$accordion-button-icon-dark:         url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='#{$accordion-icon-color-dark}'><path fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708.708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/></svg>") !default;
+$accordion-button-active-icon-dark:  url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='#{$accordion-icon-active-color-dark}'><path fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708.708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/></svg>") !default;
 // scss-docs-end sass-dark-mode-vars