app/common/styles/directives/app-navigation.scss

$nav__toplvlWidth: 240px;
$nav__top-level-color: $color--blue-100;
$nav__top-level-text-secondary: $color--grey-20;
$nav__second-level-text-primary: $color--teal-50;
$nav__second-level-text-secondary: $primary-light;
$nav__hover-over-outline: $color--grey-40;

//Navigation icons
.nav__wrapper {
  height: 100%;
  position: absolute;
  top: 0;
  z-index: 100;
}

// Top level navigation
#nav__top-level {
  background: $nav__top-level-color;
  position: fixed;
  left: 0;
  top: 0;
  bottom: 0;
  list-style-type: none;
  padding: 22px 0 0 0;
  margin: 130px 0 0 0;
  width: $nav__toplvlWidth;
  overflow-y: auto;
  >li {
    margin: 0;
    height: 3em;
    &.opened{
      height: inherit;
      .nav-link{
        color: $primary-light;
      }
    }
  }
  > li > a,
  > li > button {
    height: 3.3em;
  }
  button,
  a,
  span {
    &:hover {
      &.opened{
        color: $primary-light;
      }
    }
  }
  .nav-icon {
      height: 26px;
      float: left;
      margin: 2px 0 0 1px;
      width: 26px;
      fill: $primary-light;
      svg {
        height: inherit;
        width:  26px;
        max-width: inherit;
        fill: $primary-light;
      }
  }
  .nav-link {
      float: left;
      font-size: 15px;
      padding: 9px 0 0 7px;
      margin-left: 5px;
      &:focus{
        outline: 0;
      }
    }
}

.nav__wrapper button {
  background: transparent;
  border: 0;
  color: $primary-light;
  width: 95%;
  padding: 5px 5px 9px 10px;
  margin: 0 0 0 6px;
  display: block;
  text-align: center;
  white-space: normal;
  border-radius: 0;
  text-decoration: none;
  border: 1px solid transparent;
  font-weight: normal;
  font-size: 13px;
  &:hover,
  &:focus {
    background: fade-out(#ffffff, 0.9);
    color: $nav__top-level-text-secondary;
    border-radius: 0;
    border: 1px solid $nav__hover-over-outline;
    outline: 0;
  }
  .icon {
    margin-left: .3em;
    margin-top: .6em;
  }
  img {
    width: 2em;
    height: 2em;
  }
}

.nav__second-level  {
  list-style-type: none;
  opacity: 0;
  left: $nav__toplvlWidth;
  padding: 0;
  margin: 0;
  transform: scaleY(0);
  transform-origin: 0 0;
  transition: all $duration--moderate-01 $standard-easing--expressive;
  overflow: hidden;
  line-height: 0;
  a {
    color: $primary-light;
    width: 95%;
    padding: 6px 5px 8px 50px;
    margin: 0 0 0 6px;
    white-space: normal;
    text-decoration: none;
    border: 1px solid transparent;
    font-weight: normal;
    font-size: .8rem;
    &:hover,
    &:focus {
      background: fade-out(#ffffff, 0.9);
      color: $nav__second-level-text-secondary;
      border-radius: 0;
      border-color: $nav__hover-over-outline;
      outline: 0;
    }
  }
  &.opened {
    line-height: 1.1;
    overflow: visible;
    opacity: 1;
    transform: scaleY(1);
    transition: all $duration--moderate-01 $standard-easing--expressive;
    li a{
      display:block;
    }
  }

  li:hover
  {
    margin-left: 17px;
    margin: 0;
    padding: 0;
    a{
      padding-left: 50px;
    }
  }

  li {
    &:focus,
    &:hover {
      a {
        color: $nav__second-level-text-secondary;
      }
    }
    &.active {
      a span {
        color: $nav__second-level-text-primary;
      }
    }
  }
}