@mixin aspect-ratio($width, $height) {
  position: relative;
  &:before {
    display: block;
    content: "";
    width: 100%;
    padding-top: ($height / $width) * 100%;
  }
  > .inner {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
  }
}

@mixin color-svg($svg, $color) {
    -webkit-mask: url($svg) no-repeat center;
    -webkit-mask-size: 100%;
    background-color: $color;
}
@mixin header-icon-white($svg) {
  @include color-svg($svg, rgba(255,255,255, 0.8));
  &:focus, &:hover {
    @include color-svg($svg, white);
  }
}
@mixin header-icon-black($svg) {
  @include color-svg($svg, rgba(0,0,0, 0.5));
  &:focus, &:hover {
    @include color-svg($svg, black);
  }
}
@mixin avatar-colors {
  &.red         { background-color: $material_red         ; }
  &.pink        { background-color: $material_pink        ; }
  &.purple      { background-color: $material_purple      ; }
  &.deep_purple { background-color: $material_deep_purple ; }
  &.indigo      { background-color: $material_indigo      ; }
  &.blue        { background-color: $material_blue        ; }
  &.light_blue  { background-color: $material_light_blue  ; }
  &.cyan        { background-color: $material_cyan        ; }
  &.teal        { background-color: $material_teal        ; }
  &.green       { background-color: $material_green       ; }
  &.light_green { background-color: $material_light_green ; }
  &.orange      { background-color: $material_orange      ; }
  &.deep_orange { background-color: $material_deep_orange ; }
  &.amber       { background-color: $material_amber       ; }
  &.blue_grey   { background-color: $material_blue_grey   ; }
  &.grey        { background-color: #999999               ; }
  &.default     { background-color: $blue                 ; }
}
@mixin dark-avatar-colors {
  &.red         { background-color: $dark_material_red         ; }
  &.pink        { background-color: $dark_material_pink        ; }
  &.purple      { background-color: $dark_material_purple      ; }
  &.deep_purple { background-color: $dark_material_deep_purple ; }
  &.indigo      { background-color: $dark_material_indigo      ; }
  &.blue        { background-color: $dark_material_blue        ; }
  &.light_blue  { background-color: $dark_material_light_blue  ; }
  &.cyan        { background-color: $dark_material_cyan        ; }
  &.teal        { background-color: $dark_material_teal        ; }
  &.green       { background-color: $dark_material_green       ; }
  &.light_green { background-color: $dark_material_light_green ; }
  &.orange      { background-color: $dark_material_orange      ; }
  &.deep_orange { background-color: $dark_material_deep_orange ; }
  &.amber       { background-color: $dark_material_amber       ; }
  &.blue_grey   { background-color: $dark_material_blue_grey   ; }
  &.grey        { background-color: #666666               ; }
  &.default     { background-color: $blue                 ; }
}

// TODO: Deduplicate these! Can SASS functions generate property names?
@mixin message-replies-colors {
  &.red         { border-left-color: $material_red         ; }
  &.pink        { border-left-color: $material_pink        ; }
  &.purple      { border-left-color: $material_purple      ; }
  &.deep_purple { border-left-color: $material_deep_purple ; }
  &.indigo      { border-left-color: $material_indigo      ; }
  &.blue        { border-left-color: $material_blue        ; }
  &.light_blue  { border-left-color: $material_light_blue  ; }
  &.cyan        { border-left-color: $material_cyan        ; }
  &.teal        { border-left-color: $material_teal        ; }
  &.green       { border-left-color: $material_green       ; }
  &.light_green { border-left-color: $material_light_green ; }
  &.orange      { border-left-color: $material_orange      ; }
  &.deep_orange { border-left-color: $material_deep_orange ; }
  &.amber       { border-left-color: $material_amber       ; }
  &.blue_grey   { border-left-color: $material_blue_grey   ; }
  &.grey        { border-left-color: #999999               ; }
  &.default     { border-left-color: $blue                 ; }
}
@mixin dark-message-replies-colors {
  &.red         { border-left-color: $dark_material_red         ; }
  &.pink        { border-left-color: $dark_material_pink        ; }
  &.purple      { border-left-color: $dark_material_purple      ; }
  &.deep_purple { border-left-color: $dark_material_deep_purple ; }
  &.indigo      { border-left-color: $dark_material_indigo      ; }
  &.blue        { border-left-color: $dark_material_blue        ; }
  &.light_blue  { border-left-color: $dark_material_light_blue  ; }
  &.cyan        { border-left-color: $dark_material_cyan        ; }
  &.teal        { border-left-color: $dark_material_teal        ; }
  &.green       { border-left-color: $dark_material_green       ; }
  &.light_green { border-left-color: $dark_material_light_green ; }
  &.orange      { border-left-color: $dark_material_orange      ; }
  &.deep_orange { border-left-color: $dark_material_deep_orange ; }
  &.amber       { border-left-color: $dark_material_amber       ; }
  &.blue_grey   { border-left-color: $dark_material_blue_grey   ; }
  &.grey        { border-left-color: #666666                    ; }
  &.default     { border-left-color: $blue                      ; }
}

@mixin invert-text-color {
  color: white;

  &::selection {
    background: white;
    color: $grey_d;
  }
}