I hope you are well today and thank you for your question.
You can try achieving this using Yellow Pencil editor in the responsive mode as described in the below page.
There isn’t any responsive setting to increase its size.
You can use Yellow pencil responsive tool to increase its size on mobile as described below.
If you can’t do this using Yellow pencil editor then to achieve this, you have to develop custom code in the child theme of Jevelin theme.
Developing custom code for custom functionality is beyond the scope of support that we provide here. Please see https://themeforest.net/item/jevelin-multipurpose-premium-responsive-wordpress-theme/14728833/support
If you are not a developer then you can consider hiring a developer to develop it for you. You can hire a developer from any freelance site. Shufflehound recommends the developer https://www.upwork.com/freelancers/~011652ffec8865c6d5
To help us keep support thread separates could you please create a new thread for each of your other questions instead of asking them in your single thread as it makes the thread messy and hard to read.
If you want to you can also add a reference to this thread in your newly created thread.
We would be more than happy to help you with your new thread.