app.component.scss

.main {
  height: 100vh;
  width: 100vw;
  display: flex;
  flex-direction: column;
  flex-wrap: nowrap;
  justify-content: center;
  align-items: center;
  background-color: black;
}

.status {
  color: greenyellow;
  font-size: 25px;
}

.scroll-container {
  background-color: black;
  color: greenyellow;
  border-radius: 5px;
  border: 2px solid greenyellow;
  width: 40vw;
  height: 40vh;
  padding: 10px 20px;
  overflow-y: scroll;
  -ms-overflow-style: none; /* IE and Edge */
  scrollbar-width: none; /* Firefox */
  &::-webkit-scrollbar { /* Chrome, Safari and Opera */
    display: none;
  }

  .scroll-up-note {
    position: fixed;
    width: inherit;
    text-align: center;
    z-index: 3;
    display: none;
    color: black;
    span {
      background-color: white;
      font-size: 15px;
      padding: 5px 10px;
      border-radius: 4px;
      box-shadow: 0 1px 4px 1px lightgray;
      opacity: .8;
      &:hover {
        cursor: pointer;
        opacity: 1;
      }
    }
  }
  .scroll-down-note {
    position: sticky;
    bottom: 0;
    width: inherit;
    text-align: center;
    z-index: 3;
    display: none;
    color: black;
    span {
      background-color: white;
      font-size: 15px;
      padding: 5px 10px;
      border-radius: 4px;
      box-shadow: 0 1px 4px 1px lightgray;
      opacity: .8;
      &:hover {
        cursor: pointer;
        opacity: 1;
      }
    }
  }

  &[topScroll]:not([topScroll='0']) {
    // content is not scrolled to the top
    .scroll-up-note {
      display: block;
    }
    .shadow {
      width: 100%;
      box-shadow: 0px 20px 50px 30px black;
      height: 0.1px;
      z-index: 5;
      position: sticky;
      top: -30px;
    }
  }
  &[bottomScroll]:not([bottomScroll='0']) {
    // content is not scrolled to the bottom
    .scroll-down-note {
      display: block;
    }
    .bottom-shadow {
      width: 100%;
      box-shadow: 0 -20px 50px 20px black;
      height: 0.1px;
      z-index: 5;
      position: sticky;
      bottom: -10px;
    }
  }
}