<div class="box">
  <div class="circle">
    <div class="dot"></div>
    <div class="inset">
      <div class="dot"></div>
    </div>
    <div class="ray-box"></div>
  </div>
</div>

<div class="control">
  <div class="item">
    <label for="geometry-box">geometry-box:</label>
    <select id="geometry-box">
      <option value="margin-box">margin-box</option>
      <option value="border-box">border-box</option>
      <option value="padding-box">padding-box</option>
      <option value="content-box">content-box</option>
  </select>
  </div>
</div>

* {
  box-sizing: border-box;
}
:root {
  --geometryBox: margin-box;
}
body {
  width: 100vw;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 10vh;
}

.box {
  width: 60vh;
  height: 60vh;
  border: 1px dashed #666;
  position: relative;
  margin: 1vh;
}

.circle {
  width: 60vh;
  height: 60vh;
  border: 1px dashed #f36;
  border-radius: 10vh;
}

.dot {
  width: 1vh;
  height: 1vh;
  background-color: #000;
  border-radius: 50%;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 2;
  display: flex;
  justify-content: center;
  align-items: center;
}

.inset {
  width: 10vh;
  height: 10vh;
  background-color: #89f;
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
  offset-path: var(--geometryBox);
  
  .dot {
    background-color: red;
  }
}

.control {
  padding-top: 4vh;
  display: flex;
  align-items: center;
  justify-content: center;
  
  .item {
    margin: 0 1vh;
    display: flex;
    justify-content: center;
    align-items: center;
  }
}

const insetEle = document.querySelector('.inset')
const geometryBox = document.getElementById('geometry-box')

geometryBox.addEventListener('change', (e) => {
  console.log(e.target.value)
  insetEle.style.setProperty('--geometryBox', e.target.value)
})