Accessing and changing property of 'moveable-control-box'

[irinalabuac]

Hello, I am new to VueJs and I am trying to access and change the property of blue bounding box. I set it to zero opacity at the moment like that: .moveable-control-box { opacity: 0; }
but I would like enable user to turn opacity on and off.

I tried calling class 'moveable-control-box', and 'moveable' as well but I get
Error in v-on handler: "TypeError: Cannot read property 'style' of undefined",

Is there any way to access this class and change it? Thank you!