html,
body {
  margin: 0;
  padding: 0;
}

:root {
  --progressbar-bg: lightgrey;
  --start: red;
  --middle: blue;
  --finish: green;
}

.container {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  padding: 0 50px;
}

.progress-bar,
.progress-status {
  height: 30px;
  background: var(--progressbar-bg);
  border-radius: 50px;
  width: 100%;
}

.progress-bar {
  position: relative;
}

.progress-status {
  position: absolute;
  top: 0;
  animation: progress 5s infinite;
  animation-timing-function: linear;
  animation-fill-mode: forwards;
}

@keyframes progress {
  0% {
    width: 0%;
    background-color: var(--start);
  }
  50% {
    width: 50%;
    background-color: var(--middle);
  }
  100% {
    width: 100%;
    background-color: var(--finish);
  }
}