How to make background image fit correctly inside a board without losing responsiveness

Question

I have code in which there is class box, i have given backgroundimage to class box box1.

my problem is that the im

Answer 1

I think you are tackling this the wrong way. I would instead extract the board element from the main background and use it as an element alone:

html {
  background: #afffdc;
}

#container {
  position: fixed;
  bottom: 0;
  left: 100px;
  background: url(https://i.stack.imgur.com/CM15R.jpg) top/contain no-repeat;
  height: 50vh;
  width: 29vh;
  max-width: 20vw;
  max-height: 35vw;
}

.box {
  padding-top: 173%;
  background: url(https://picsum.photos/200/300) 50% 5%/86% 27% no-repeat;
}

Update

Here is a transparent version

html {
  background: linear-gradient(to right,pink, lightblue);
}

#container {
  position: fixed;
  bottom: 0;
  left: 100px;
  background: url(https://i.stack.imgur.com/ctB0T.png) top/contain no-repeat;
  height: 50vh;
  width: 29vh;
  max-width: 20vw;
  max-height: 35vw;
}

.box {
  padding-top: 173%;
  background: url(https://picsum.photos/200/300) 50% 5%/86% 27% no-repeat;
}