/*关键语句*/
clip-path: polygon(0 0, 0% 100%, 100% 100%, 100% 20%, 90% 0%);

例子

/*例子1*/
.title {
    font-size: 2rem;
    line-height: 3rem;
    height: 3rem;
    padding: 0 1rem 0 .4rem;
    background: #fff;
    clip-path: polygon(0 0, 0% 100%, 100% 100%, 100% 20%, 90% 0%);
    -webkit-clip-path: polygon(0 0, 0% 100%, 100% 100%, 100% 20%, 90% 0%);

}
/*例子2*/
.name {
    width: 100%;
    height: 5.6rem;
    color: #bfc8db;
    display: flex;
    justify-content: center;
    align-items: center;
    clip-path: polygon(5% 0, 0% 12%, 0% 100%, 100% 100%, 100% 0%);
    -webkit-clip-path: polygon(5% 0, 0% 12%, 0% 100%, 100% 100%, 100% 0%);
}

效果图:

image.png
image.png

可以发现,坐标点是按照逆时针顺序,首尾相连的.没有始终点之分.

--by Affandi ⊙▽⊙