Learn how to feather the edges of blocks using CSS

Question

How do I modify my CSS to have a feathered blur effect on the edges of the box? I would like the background of the box to have a frosted glass effect, and instead of sharp edges around it, have a feathered effect that gradually blends into the background, but I don't know how to modify the current CSS. Hope to get your help, thank you.

.wrap {
  position: relative;
  width: 100%;
  height: 100vh;
  background-image: url('https://images.unsplash.com/photo-1593642634443-44adaa06623a?ixlib=rb-1.2.1&ixid=MnwxMjA3fDF8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1625 &q=80 ');
  background-size: cover;
  .box {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    width: 200px;
    height: 200px;
    background-color: red;
    border-radius: 50%;
    background-color: rgba(225, 225, 225, 10%);
    backdrop-filter: blur(2px);
  }
}

<div class="wrap">
  <div class="box"></div>
</div>

Answer 1

All I understand is to add any code snippet below:

box-shadow: inset 2px 2px 15px #fff; // or box-shadow: inset 2px 2px 15px rgba(255,255,255,.5)