notifications-admin/app/assets/stylesheets/govuk_template/_accessibility.scss

/* For image replacement */
.ir {
  display: block;
  text-indent: -999em;
  overflow: hidden;
  background-repeat: no-repeat;
  text-align: left;
  direction: ltr;

  br {
    display: none;
  }
}

/* Hide for both screenreaders and browsers */
.hidden {
  display: none;
  visibility: hidden;
}

/* Hide only visually, but have it available for screenreaders */
.visually-hidden,
.visuallyhidden {
  position: absolute;
  left: -9999em;

  /*
   * Extends the .visuallyhidden class to allow the element to be
   * focusable when navigated to via the keyboard
   */
  &.focusable:active,
  &.focusable:focus {
    clip: auto;
    height: auto;
    margin: 0;
    overflow: visible;
    position: static;
    width: auto;
  }
}

/* Hide visually and from screenreaders, but maintain layout */
.invisible {
  visibility: hidden;
}

/* Give a strong clear visual idea as to what is currently in focus */
a {
  -webkit-tap-highlight-color: rgba(0, 0, 0, 0.3);
}

a:focus {
  background-color: $focus-colour;
  outline: 3px solid $focus-colour;
}

/* Make skiplinks visible when they are tabbed to */

.skiplink {
  position: absolute;
  left: -9999em;
}

.skiplink:focus {
  position: static;
}

#skiplink-container {
  text-align: center;
  background: $black;

  div {
    text-align: left;
    margin: 0 auto;
    max-width: 1020px;
  }

  .skiplink {
    @include inline-block;
    margin: 0.75em 0 0 30px;
  }
}

input:focus,
textarea:focus,
select:focus,
button:focus,
#global-header input:focus {
  outline: 3px solid $focus-colour;
}

#global-header {
  h1 a:focus {
    background-color: transparent;
    outline: none;
  }

  a:focus {
	  color: $black;
  }
}