CSHARP

center an image horizontally and vertically

.center{
    margin: 0;
    position: absolute;
    top: 50%;
    left: 50%;
    -ms-transform: translate(-50%, -50%);
    transform: translate(-50%, -50%);
}

css horizontal and vertical center image in div

.center-img {
	margin: 0;
    position: absolute;
    top: 50%;
    left: 50%;
    -ms-transform: translate(-50%, -50%);
    transform: translate(-50%, -50%);
}

// if that does not work you can try
.center-img {
	margin-left: auto;
	margin-bottom: auto;
	margin-top: auto;
	margin-right: auto;
}