How to get rid of the curb?

Question

css

I have the next element rendered with css.
The problem is that browsers draw such a thin, but very unsympathetic border. Does anyone know how to get rid of this curb?
Reset, set a white border, etc. - Does not help.

Answer 1

This is not your border, but the background color that goes beyond the borders of the gradient.
I would do so and accordingly would reduce the figure a little
height: 200px;
width: 300px;
background: gray;
margin: 50px 0 0 20px;
-moz-transform: matrix(1, -0.3, -0.2, 1, 0, 0);
-webkit-transform: matrix(1, -0.3, -0.2, 1, 0, 0);
-o-transform: matrix(1, -0.3, -0.2, 1, 0, 0);
-ms-transform: matrix(1, -0.3, -0.2, 1, 0, 0);
transform: matrix(1, -0.3, -0.2, 1, 0, 0);
box-shadow:0px 0px 10px 4px gray ;
}

Answer 2

Try setting the shadow like this: 0 0 10px #AAAAAA, 0 0 10px #AAAAAA