JSFiddle - React, Tailwind, and code Playground

HTML

<div class="line_container">
<div class="glass-line line-1">&#x1F4A9</div>
<div class="line_bottom"></div>
</div>

CSS

.line-container {
  display: flex;
  position: fixed;
}
.line_bottom {
  width: 100%;
  height: 11px;
  background-color: rgb(255, 0, 0);
}

.glass-line {
  width: fit-content;
  position: relative;
  font-size: 60px;
  animation: tyda_suda 5s infinite alternate;
  background-color: rgb(55, 0, 0, 0.5);
}

@keyframes tyda_suda {
  from {
    left: 0;
  }
  to {
    left: 90%;
  }
}