[Solved] Position absolute is not relative to its its parent CSS

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*{
  box-sizing: border-box;
}
.empty-container {
  height: 100px;
  border: 1px solid gray;
}

.container {
  height: calc(100% - 100px);
  border: 1px solid red;
  display: flex;
  position: relative;
}
.component-loader{
  border: 1px solid gray;
  position: absolute;
  height: 90px;
  width: 90px;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  margin: auto;
}
.loader-spinner:before {
  content: "";
  margin: 0;
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  border-width: 8px;
  border-style: solid;
  border-color: green #ccc #ccc;
  border-radius: 100%;
  animation: rotation .7s infinite linear;
}
@-webkit-keyframes rotation {
  0% {
    -webkit-transform: rotate(0deg);
  }
  100% {
    -webkit-transform: rotate(360deg);
  }
}
@keyframes rotation {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}
<div style="height: 600px">
  <div class="empty-container"></div>
  <div class="container">
    <div class="component-loader">
      <div class="loader-spinner"></div>
    </div>
  </div>
</div>

2

solved Position absolute is not relative to its its parent CSS