discourse/app/assets/stylesheets/mobile/header.scss

// --------------------------------------------------
// Discourse header
// --------------------------------------------------

.d-header {
  height: 3.66em;

  // some protection for text-only site titles
  .title {
    max-width: 75%;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    -webkit-animation: fadein 0.5s;
    animation: fadein 0.5s;
    a {
      display: block;
      width: 100%;
    }
  }

  #site-logo {
    max-height: 2.4em;
    max-width: 100%;
  }
  #site-text-logo {
    margin: 0;
    font-size: $font-up-1;
  }
  .extra-info-wrapper {
    .extra-info {
      // header title should not be centered if there's no tags / categories
      &:not(.two-rows) {
        min-height: 2.25em;
      }
      h1 {
        font-size: $font-0;
      }
      .private-message-glyph-wrapper {
        float: left;
      }
    }
  }
  button.sign-up-button {
    display: none;
  }
  // styles for mobile scroll logo / topic
  .panel {
    -webkit-animation: fadein 0.5s;
    animation: fadein 0.5s;
  }
  &.scroll-down .panel {
    display: none;
  }
}

.d-header-icons {
  .d-icon {
    line-height: $line-height-medium;
  }
  .active .icon {
    &:after {
      margin-top: -1px;
    }
  }
}

#main-outlet {
  padding-top: 4.2857em;
}

.search-link .badge-category {
  display: none;
}