Skew

HTML

<div class="skew"></div>

CSS

.skew {
    width: 100px;
    height: 100px;
    background: teal;
    transform: skew(20deg, -30deg);
}

This example will skew the div by 20 degrees on the X axis and by - 30 degrees on the Y axis.

The center of the transform is in the center of the div, 50% from left and 50% from top.

See the result here.