如何创建带有中空V形的CSS进度条？

<div class="progress-bar">
  <div class="progress"></div>
</div>

.progress-bar {
  width: 200px;
  height: 20px;
  background-color: #f2f2f2;
  position: relative;
}

.progress {
  width: 0%;
  height: 100%;
  background-color: #4caf50;
  position: absolute;
  top: 0;
  left: 0;
  animation: progress-animation 5s linear infinite;
}

@keyframes progress-animation {
  0% {
    width: 0%;
  }
  100% {
    width: 100%;
  }
}

.progress:before {
  content: "";
  position: absolute;
  top: -10px;
  left: calc(50% - 10px);
  border-left: 10px solid transparent;
  border-right: 10px solid transparent;
  border-bottom: 10px solid #4caf50;
}

.progress:after {
  content: "";
  position: absolute;
  bottom: -10px;
  left: calc(50% - 10px);
  border-left: 10px solid transparent;
  border-right: 10px solid transparent;
  border-top: 10px solid #4caf50;
}