Remove thumb for canvas-slider-response plugin till response is made and select the "Continue" button by pressing 'ENTER' button ?

[prashantig25]

Hello All,
In my behavioural study, participants are presented with a canvas drawn stimuli and they have to respond with the slider. Currently, I have set the slider to start at 0. However, it would be preferable to not have the thumb visible to the participants. That is, the thumb becomes visible when participants respond by dragging the slider. I made adjustments to the jspsych.css to change the visibility of the thumb as suggested in an earlier discussion https://github.com/jspsych/jsPsych/discussions/1660#discussion-3286016 i.e. Query number 1660.
However, that does not work when I upload the edited jspsych.css file on Cognition. I usually host my study on Cognition, and the slider thumk still appears. Is there a way to change it so that the slider thumb only appears when the participant responds by clicking or dragging the slider?

Another query is regarding the 'Continue' button. Currently, once participants drag the slider, they have to click on the 'Continue' button with the mouse. Is there anyway to also have the option of pressing the 'Enter' key to proceed to the next trial?

Thank you for the help!
Sincerely,
Prashanti