3pushbutton

  <div class="b1"></div>
  <div class="c1"></div>
  <div class="c2"></div>
  <div class="c3"></div>

<style>
  body{
    background:#6592CF;
    margin:0;
    display:flex;
    justify-content:center;
    align-items:center;
    z-index:1;
  }

  .b1{
    width:300px;
    height:150px;
    background:#243D83;
    position:absolute;
    z-index:2;
  }

  .c1{
    background:#6592CF;
    height:250px;
    width:250px;
    border-radius:50%;
    position:absolute;
    z-index:3;
  }

  .c2{
    background:#243D83;
    height:150px;
    width:150px;
    position:absolute;
    border-radius:50%;
    z-index:4;
  }

  .c3{
    position:absolute;
    z-index:5;
    background:#EEB850;
    height:50px;
    width:50px;
    border-radius:50%;
  }
</style>