css opacity persist after animation code example

Example 1: how to make animation stay on 100%

animation-fill-mode:forwards;

Example 2: css opacity animation

<style>
.myelement{
  animation: fade-out;
}

@keyframes fade-out{
  0%{
    opacity: 1.0
  }
  100{
    opacity: 0.0
  }
}
</style>