Calculator in LMS.
While the button used to open the calculator provides a textual equivalent for content for screen reader users, there is no visual indication of what this control will do if a user enables high contrast mode.
CSS background images are removed by browser high contrast modes, leaving these users with no indication of what this content is.
Developers must provide an alternative means for this css background image.
An inline img element would be the most accessible option. However, and SVG element, with an appropriate textual alternative (as is already being provided) could be one means that will not be removed by high contrast mode.