gab-social/app/javascript/styles/gabsocial/basics.scss

@function hex-color($color) {
  @if type-of($color)=='color' {
    $color: str-slice(ie-hex-str($color), 4);
  }

  @return '%23'+unquote($color)
}

html {
  @include font-roboto();
  @include font-weight(normal);
  font-size: 62.5%;
  text-size-adjust: 100%;
  -ms-text-size-adjust: 100%;
  -webkit-text-size-adjust: 100%;
}

body {
  font-size: 16px;
  line-height: 19px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizelegibility;
  font-feature-settings: "kern";
  -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
  -webkit-tap-highlight-color: transparent;
  color: white;
  background: $gab-background-base;

  &.theme-gabsocial-light {
    color: $gab-default-text-light;
    background: $gab-background-base-light;
  }

  &.system-font {
    // system-ui => standard property (Chrome/Android WebView 56+, Opera 43+, Safari 11+)
    // -apple-system => Safari <11 specific
    // BlinkMacSystemFont => Chrome <56 on macOS specific
    // Segoe UI => Windows 7/8/10
    // Oxygen => KDE
    // Ubuntu => Unity/Ubuntu
    // Cantarell => GNOME
    // Fira Sans => Firefox OS
    // Droid Sans => Older Androids (<4.0)
    // Helvetica Neue => Older macOS <10.11
    // $font-sans-serif => web-font (Roboto) fallback and newer Androids (>=4.0)
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Oxygen", "Ubuntu", "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue", $font-sans-serif, sans-serif;
  }

  &.app-body {
    position: absolute;
    width: 100%;
    padding: 0;
    overflow: hidden;
    overflow-y: scroll;

    &.with-modals--active {
      overflow-y: hidden;
    }
  }

  &.lighter {
    background: $ui-base-color;
  }

  &.with-modals {
    overflow-x: hidden;
    overflow-y: scroll;

    &--active {
      overflow-y: hidden;
      margin-right: 13px;
    }
  }

  &.player {
    text-align: center;
  }

  &.embed {
    background: lighten($ui-base-color, 4%);
    margin: 0;
    padding-bottom: 0;

    .container {
      position: absolute;
      overflow: hidden;

      @include size(100%);
    }
  }

  &.admin {
    background: darken($ui-base-color, 4%);
    position: fixed;
    padding: 0;

    @include size(100%);
  }

  &.error {
    position: absolute;
    text-align: center;
    color: $darker-text-color;
    background: $ui-base-color;
    padding: 0;

    @include flex(center, center);
    @include size(100%);

    .dialog {
      vertical-align: middle;
      margin: 20px;

      &__illustration {
        img {
          display: block;
          max-width: 470px;
          margin-top: -120px;

          @include size(100%, auto);
        }
      }

      h1 {
        @include text-sizing(20px, 400, 28px);
      }
    }
  }
}

button {
  font-family: inherit;
  cursor: pointer;

  &:focus {
    outline: none;
  }
}

.app-holder {
  &,
  &>div {
    outline: 0 !important;

    @include flex(center, start);
    @include size(100%);
  }
}