CSS0027： div 倒角效果

1，

<div id="test"></div>


        #test {
        display: inline-block;
        width: 100px;
        height: 100px;
        background: linear-gradient(135deg, transparent 10px, #58a 0) top left,
                linear-gradient(-135deg, transparent 10px, #58a 0) top right,
                linear-gradient(-45deg, transparent 10px, #58a 0) bottom right,
                linear-gradient(45deg, transparent 10px, #58a 0) bottom left;
        background-size: 50% 50%;
        background-repeat: no-repeat;
        }