fix(theme): fix scss warning and future error

[matheo]

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• [x] I read and followed the CONTRIBUTING.md guide.

Short description of what this resolves:

I've been getting this on GitHub Actions logs:

so this fix the issue just following the recommendation.

[sonarqubecloud[bot]]

Quality Gate failed

Failed conditions
5.6% Duplication on New Code (required ≤ 3%)

See analysis details on SonarCloud