Odoo 12 CE is supposed to mobile responsive if it is has some issues raise the issue in Github and see whether it will get fixed or what they about it.

As a solution for this, As you have told he can use some responsive theme available in the store

^ Actually, no Cybrosys, there has never been an official statement it would be fully mobile responsive. It is only a best efforts. Their enterprise version is fully mobile and they made the official statement for enterprise though. Honestly the community version is still not very workable on mobile.

Even on Odoo's website, https://www.odoo.com/page/editions they are still shown mobile is not supported for CE. They could be only referencing the mobile app but I am sure they would make a disclaimer if CE was supported on mobile from the browser.

Thank you all and @James Dominy, I will have a look at the theme you refer. I don't exactly need a mobile solution for Odoo CE at this stage. I also believe that "mobile" is further beyond being responsive and theme related as you all stated. I will check the theme and look for additional solutions for this and keep you informed. Thank you all once again. Best regards

@James, I have tested the module you refer and get my requirements satisfied.

For those who's facing similar problems, the best option is really to find a theme that helps them or at least one they can change to meet they're requirements.

Thank you once again