Not able to align concentric inner circle inside my outer div - html

Question

I am trying to create a sort of circle and trying to embed a inner circle but the inner circle is not positioning as required in the image.
.outer-circle {
width: 200px;
height: 200px;
background-color: coral;
border-radius: 50% 50% 0 0;
transform: rotate(90deg);
}
.inner-circle {
width: 100px;
height: 100px;
margin-left: 10px;
margin-top: 10px;
background-color: blue;
border-radius: 50%;
}
<div class="outer-circle">
<div class="inner-circle"></div>
</div>
How can I position my inner circle as required without writing any Javascript.

Answer 1

Following works:
.outer-circle {
width: 200px;
height: 200px;
background-color: coral;
border-radius: 50% 50% 0 0;
transform: rotate(90deg);
padding-top: 15px;
}
.inner-circle {
width: 160px;
height: 160px;
margin-left: 20px;
margin-top: 10px;
background-color: blue;
border-radius: 50%;
}
<div class="outer-circle">
<div class="inner-circle"></div>
</div>

Answer 2

One of the solutions would be to use absolute positioning:
.outer-circle {
width: 200px;
height: 200px;
background-color: coral;
border-radius: 50% 50% 0 0;
transform: rotate(90deg);
position: relative;
}
.inner-circle {
width: 100px;
height: 100px;
background-color: blue;
border-radius: 50%;
position: absolute;
top: 50%;
right: 50%;
transform: translate(50%, -50%);
}
<div class="outer-circle">
<div class="inner-circle"></div>
</div>

Answer 3

.outer-circle {
width: 100px;
height: 100px;
background-color: coral;
border-radius: 50% 50% 0 0;
transform: rotate(90deg);
padding: 10px;
}
.inner-circle {
width: 100px;
height: 100px;
background-color: blue;
border-radius: 50%;
}
<div class="outer-circle">
<div class="inner-circle"></div>
</div>
I've removed the margin and added a padding to the .outer-circle. That's gotta be the easiest way for now. Basically you make height the same on both circles, adding the padding to the outer-circle creates the gap between the two, the bigger the larger it will get.

Answer 4

Additional info:
margin(https://developer.mozilla.org/en-US/docs/Web/CSS/margin)
position(https://developer.mozilla.org/en-US/docs/Web/CSS/position)
.outer-circle {
width: 200px;
height: 200px;
background-color: coral;
border-radius: 50% 50% 0 0;
transform: rotate(90deg);
}
.inner-circle {
position:absolute;
width: 100px;
height: 100px;
margin: 50px;
background-color: blue;
border-radius: 50%;
}
<div class="outer-circle">
<div class="inner-circle"></div>
</div>

Answer 5

Use transform:translate
.outer-circle {
width: 200px;
height: 200px;
background-color: coral;
border-radius: 50% 50% 0 0;
transform: rotate(90deg);
}
.inner-circle {
width: 100px;
height: 100px;
margin-left: 50px;
margin-top: 50px;
background-color: blue;
border-radius: 50%;
transform: translate(0px,50px);
}
<div class="outer-circle">
<div class="inner-circle"></div>
</div>