css中的曲线形状纸张

.paper {
  position: relative;
  width: 200px;
  height: 300px;
  background-color: #fff;
  transform: rotate(-10deg);
  border-radius: 10px;
  overflow: hidden;
}

.paper::before {
  content: "";
  position: absolute;
  top: -20px;
  left: -20px;
  width: 40px;
  height: 40px;
  background-color: #fff;
  border-radius: 50%;
  transform: rotate(45deg);
}

.paper::after {
  content: "";
  position: absolute;
  bottom: -20px;
  right: -20px;
  width: 40px;
  height: 40px;
  background-color: #fff;
  border-radius: 50%;
  transform: rotate(45deg);
}