.circle {
    border: solid red;
    border-radius: 50%;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}
.light {
    height: 20px;
    width: 20px;
    transform: translate(-50%, -50%);
    border-radius: 50%;
    background: red;
    box-shadow: 0 0 5px red, 0 0 2px FireBrick, 0 0 1px DarkRed;
    position: absolute;
    top: 50%;
    left: 50%;
}