Progress Bar

HTML

<div class="container">
  <div class="progress">
  </div>
</div>

CSS

@keyframes progress {
  from {
    width: 10%;
  }
  to {
    width: 100%;
  }
}

.progress {
  animation: progress 10s linear;
  height: 100%;
  background-color: blue;
}

.container {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 75%;
  height: 2rem;
  border: 1px solid black;
  box-shadow: 1px 1px gray;
}