I need to create a little green part for the filling of the circle, as in this image
I've created the external circle with a pseudoelement:
a::after {
content: "";
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
border-radius: 50%;
border: 5px solid rgb(27, 26, 30);
z-index: 1;
}