fix adornment fill variable never being used

[steppy452]

PR Checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[x] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Other... Please describe:

What is the current behavior?

--input-adornment-fill variable was defined in the theme file, but never used

Issue Number: N/A

What is the new behavior?

added the use of --input-adornment-fill in the input css file.

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information