<div class="rect">
<div class="lb c">
<div class="db c">
<div class="ylw c"></div>
</div>
</div>
</div>
<style>
body {
background: #6592CF;
margin: 0;
display: flex;
justify-content: center;
align-items: center;
}
div {
display: flex;
justify-content: center;
align-items: center;
}
.rect {
width: 300px;
height: 150px;
background: #243D83;
}
.c {
border-radius: 50%
}
.lb {
background: #6592CF;
height: 250px;
width: 250px;
}
.db {
background: #243D83;
height: 150px;
width: 150px;
}
.ylw {
background: #EEB850;
height: 50px;
width: 50px;
}
</style>