The inner circle of radio buttons are incorrectly scaled/positioned in Bootstrap themes. The radio buttons in bootstrap theme are by default dependent on "rem" unit. For applications, that specify different base for "rem" unit, than 16px, it is possible to naturally override dimensions of the radio button without any specific overrides.

In example application, the following points are important:

1. :root specifies font-size=24px. So 1rem=24px.

2. Radio buttons uses size="small". The width and height then defaults to 0.75rem=18px.

Important note, is that the wrong positioning of inner circle is most visible when scaling down the browser view. There is offset by 1px to the sides. The image in the attachments is screenshot from the application and demonstrates the offset in pixels from the sides. The first number above the radio button is the offset of the inner circle in pixels from the left, the second number after "/" is the offset of inner circle from the right.

This issue appears only if the dimensions are being increased/decreased in respect to the default "medium" size. If the radio button is scaled using "scale" CSS function, then the scaling is correctly preserved. Also I didn't notice any problem for the "medium" sized radio button in any browser view. The root font-size might not be important for bug to be reproducible, but inconsistencies are then more visible.