discourse/app/assets/stylesheets/desktop/poster_expansion.scss

// styles that apply to the "share" popup when sharing a link to a post or topic

@import "common/foundation/variables";
@import "common/foundation/mixins";

#poster-expansion {
  position: absolute;
  left: 20px;
  z-index: 990;
  @include border-radius-all(3px);
  @include box-shadow(1px 1px 5px $darkish_gray);
  background-color: $white;
  padding: 7px 7px 6px 7px;
  width: 400px;

  h1 {
    font-size: 30px;
    line-height: 33px;
    margin-bottom: 8px;
  }

  h2 {
    font-size: 20px;
    line-height: 22px;
    font-weight: normal;
  }

  h3 {
    font-size: 13px;
    font-weight: normal;
    margin-top: 5px;
  }

  .bottom {
    clear: both;
    padding-top: 10px;
  }

  img.avatar {
    float: left;
    padding-right: 10px;
  }

  p {
    margin: 0 0 5px 0;
  }

  .btn {
    margin: 0 0 7px 0;
  }
}