Vertical skeleton loader not working from bottom to top animation

I'm using both vertical and horizontal skeleton loader in a react component, please refer to this codepen - https://codepen.io/phutschi/pen/jejzbK for reference, I want to like this for vertical loader from bottom to top. Loader.js

import './loader.scss'
function Loader() {
  return (
    <div className="animated-background">
                      <div className="background-masker content-first-line"></div>
                      <div className="background-masker content-second-line"></div>
                      <div className="background-masker content-third-line"></div>
                      <div className="background-masker vertical-line"></div>
                    </div>
  )
}

export default Loader

loader.scss

 @keyframes placeHolderLoader {
    0% {
      background-position: -468px 0;
    }
    100% {
      background-position: 468px 0;
    }
  }
  @keyframes verticalPlaceHolderLoader {
    0% {
      background-position: bottom  ;
    }
    100% {
      background-position: top;
    }
  }
  .animated-background {
   
    // height: 120px;
    // position: relative;
    .background-masker{
        height: 14px;
      border-radius: 7px;
      width: 80%;
        margin-bottom: 2px;
        animation-duration: 1.3s;
        animation-fill-mode: forwards;
        animation-iteration-count: infinite;
        animation-name: placeHolderLoader;
        animation-timing-function: linear;
        background: #f6f7f8;
        background: linear-gradient(to right, #eeeeee 8%, #dddddd 18%, #eeeeee 33%);
        background-size: 100%;
        &.vertical-line{
            width: 50px;
            height: 140px;
            animation-duration: 1.3s;
            background: linear-gradient(to bottom, #eeeeee 8%, #dddddd 18%, #eeeeee 33%);
            animation-name: verticalPlaceHolderLoader;
        }
      }
  }

u can see, that I'm using separate gradient and animation for vertical lines, but the animation is not working for vertical lines, the animation should work from bottom to top.