Improving pop-up styling

**Is your feature request related to a usage problem (not a bug)? Please describe.**
The popup styling used for various alerts and functions across the app is strange and looks tacky. The popups span the entire screen in a thin section and the buttons are spread far apart.

**Describe the solution you'd like to see implemented**
To make it less of a thin line and a more neat and compact popup.

**Describe alternatives you've considered**
None.

**Screenshots**
Before changes:

Example after changes:

**Additional context**
I made the max-width of the popup 500px.
I made the flex box for the buttons 400px.
I also made the h3 -> h2.
In addition I added 40px padding to the main popup element.

I would make a PR but the way I made this test was solely for demonstration (not dynamic).