Dear @JustinasR
I have checked your website. It seems that you added style snippets to bring the language selector to the desired position on the desktop screen. However, on mobile and tablet devices, you should make the following adjustments to make it look better:
1. Regarding structure: You should not place a div tag inside a ul tag.
2. Regarding styles for mobile: Please remove the display: block; line in .shopify-localization-form on mobile so that its size does not exceed the popup.
Let me know if you need further assistance.
Regards,
Eric