ionic-framework/ionic/components/aside/aside.scss

// Aside
// --------------------------------------------------

$aside-width: 304px !default;
$aside-small-width: $aside-width - 40px !default;

$aside-transition: 0.2s ease transform !default;
$aside-backdrop-transition: 0.2s ease background-color !default;
$aside-background: $background-color !default;
$aside-shadow: -1px 0px 8px rgba(0, 0, 0, 0.2) !default;


.aside {
  position: absolute;
  top: 0;
  bottom: 0;

  left: -$aside-width;
  width: $aside-width;

  display: flex;
  flex-direction: column;

  background: $aside-background;

  transform: translate3d(0, 0, 0);
  transition: $aside-transition;

  &.no-transition {
    ion-aside-backdrop {
      transition: none;
    }
  }
  
  ion-aside-backdrop {
    z-index: $z-index-aside-backdrop;
    transition: $aside-backdrop-transition;
    transform: translateX($aside-width);
    top: 0;
    right: 0;
    left: 0;
    bottom: 0;
    position: fixed;
    background-color: rgba(0,0,0,0);;
  }


  &[type=overlay] {
    z-index: $z-index-aside-overlay;
  }

  &:not(.open):not(.changing) {
    display: none;
  }

  &[type=reveal] {
    left: 0;
  }

  &.open, {
    &[type=reveal],
    &[type=push] {
      left: 0;
    }
    &[type=overlay] {
      transform: translate3d($aside-width,0,0);

      ion-aside-backdrop {
        background-color: rgba(0,0,0,0.6);
      }
    }
  }

  &[side=right] {
    width: $aside-width;
    left: 100%;
    top: 0;
    bottom: 0;

    transform: translate3d(0,0,0);
    &.open,
    &[type=reveal] {
      transform: translate3d(-$aside-width,0,0);
    }
  }

  &[side=top] {
    height: $aside-width;
    top: -$aside-width;
    left: 0;
    right: 0;

    transform: translate3d(0,0,0);
    &.open,
    &[type=reveal] {
      transform: translate3d(0,$aside-width,0);
    }
  }

  &[side=bottom] {
    height: $aside-width;
    top: 100%;
    left: 0;
    right: 0;

    transform: translate3d(0,0,0);
    &.open,
    &.type-reveal {
      transform: translate3d(0,-$aside-width,0);
    }
  }

}

.aside-content {
  transition: $aside-transition;
  transform: translate3d(0,0,0);

  box-shadow: $aside-shadow;
  &.aside-open-left {
    transform: translate3d($aside-width,0,0);
  }

  &.aside-open-right {
    transform: translate3d(-$aside-width,0,0);
  }
}


@media (max-width: 340px) {

  .aside {
    left: -$aside-small-width;
    width: $aside-small-width;
  }

  .aside-content {
    &.aside-open-left {
      transform: translate3d($aside-small-width, 0, 0);
    }

    &.aside-open-right {
      transform: translate3d(-$aside-small-width, 0, 0);
    }
  }

}