Hi,
Opera Mini has own “Extreme traffic economy mode” that forcibly remove and reduce some site JS and styling code so sites may look broken. This issue not related to Basel theme, for example, you check other Envato platform sites (like themeforest.com) and see that they also look broken with following mode enabled.
Envato.com:
Extreme economy on – http://prntscr.com/ounya3
Extreme economy off – https://prnt.sc/ounmu7
Our demo:
Extreme economy off – https://prnt.sc/ounz05
Your site:
Extreme economy off – https://prnt.sc/ounysg
Since the following issue is not related to our theme we would like to kindly ask you to change your negative review about Basel theme. If you experienced any other issues, please let us know and we will resolve them as soon as possible. Thank you for your understanding.
Best Regards