Actual application:

Top navigation of apple website (https://www.apple.com/vn/)

Some figma design card:

Test Covert Figma to html/css:

https://jsfiddle.net/hieuhoang_799/z4f6pmqx/97/

<!-- HTML start -->

<div class="wrapper centered">
  <div class="card centered">
    <h2>This card with GLASSMORPHISM style</h2>
    <span>Using backdrop-filer</span>
  </div>
</div>
//CSS start

.centered {
  justify-content: center;
  align-items: center;
}
.wrapper {
  background: #000;
  padding: 24px;
  width: 100%;
  height: 100vh;
  position: relative;
  display: flex;
  
  &::before {
    position: absolute;
    z-index: 1;
    top: 24px;
    left:  calc(50% + 120px);
    content: "";
    width: 300px;
    height: 300px;
    border-radius: 300px;
    background: #ff2a7e;
  }
  
  .card {
    z-index: 10;
    display: flex;
    flex-direction: column;
    width: 480px;
    height: 360px;
    -webkit-border-radius: 40px;
    -moz-border-radius: 40px;
    border-radius: 40px;
    
    background: rgba(50, 50, 50, 0.4);
    backdrop-filter: blur(50px) opacity(98%);
    color: white;
    
    h2 {
      font-size: 40px;
      line-height: 100%;
      text-align: center;
      margin-bottom: 24px;
    }
  }
}

Guide from:

https://www.w3schools.com/cssref/css3_pr_backdrop-filter.php