Modify thickness Arrow of media carousel

Hi how can i change the thickness of the arrow of the media carousel?
The elementor pro support told me to do it via css, but i don t know any code.

https://www.elisirdargan.com/wp-content/uploads/2024/06/Senza-eqetitolo.png

https://www.elisirdargan.com/wp-content/uploads/2024/06/Immagine-2024-06-12-203253.png

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