discourse/app/assets/stylesheets/common/base/header.scss

.d-header {
    min-width: 100%;
    position: absolute;
    top: 0;
    z-index: 1001;
    background-color: $header_background;
    box-shadow: 0 2px 4px -2px rgba($header_primary, .25);

    .docked & {
      position: fixed;

    }

    .contents {
      margin: 10px 0;
    }

    .title {
      display: table;
      float: left;
      height: 40px;
      > a {
        display: table-cell;
        vertical-align: middle;
      }
    }

    #site-logo {
      max-height: 40px;
    }

    .fa-home {
      font-size: 20px;
      line-height: 40px;
    }

    .panel {
      float: right;
      position: relative;
    }

    .current-username {
      float: left;
      a {
        color: $header_primary;
        font-size: 14px;
        max-width: 200px;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
      }
    }
    button.login-button {
      float: left;
      margin-top: 7px;
      padding: 6px 10px;
      .fa { margin-right: 3px; }
    }
    .icons {
      float: left;
      text-align: center;
      margin: 0 0 0 5px;
      list-style: none;
      > li {
        float: left;
      }
      .icon {
        display: block;
        padding: 3px;
        color: scale-color($header_primary, $lightness: 50%);
        text-decoration: none;
        cursor: pointer;
        border-top: 1px solid transparent;
        border-left: 1px solid transparent;
        border-right: 1px solid transparent;


        &:hover {
          color: $primary;
          background-color:  scale-color-diff();
          border-top: 1px solid transparent;
          border-left: 1px solid transparent;
          border-right: 1px solid transparent;
        }
        &:active {
          color: $primary;
          background-color: scale-color-diff();
        }
      }
      .active .icon {
        position: relative;
        color: #7b7b7b;
        background-color: $secondary;
        cursor: default;
        border-top: 1px solid scale-color-diff();
        border-left: 1px solid scale-color-diff();
        border-right: 1px solid scale-color-diff();
        &:after {
          display: block;
          position: absolute;
          top: 100%;
          left: 0;
          z-index: 1101;
          width: 100%;
          height: 0;
          content: "";
          border-top: 1px solid $secondary;
        }
        &:hover {
        border-bottom: none;
        }
      }
      [class^="fa fa-"] {
        width: 32px;
        height: 32px;
        font-size: 20px;
        line-height: 32px;
        display: inline-block;
      }
      .notifications {
        position: relative;
      }
      .badge-notification {
        position: absolute;
        top: -9px;
        z-index: 1;
        margin-left: 0;
      }
      .unread-notifications {
        right: -4px;
        background-color: scale-color($tertiary, $lightness: 50%);
      }
      .unread-private-messages {
        left: -4px;
      }
    }
    .flagged-posts {
      background: $danger;
    }

}

.d-dropdown {
    display: none;
    position: absolute;
    background: $secondary;
    max-height: 417px;
    top: 100%;
    right: 0;
    z-index: 1100;
    overflow: auto;
    border: 1px solid scale-color-diff();
    padding: 5px;

    @include box-shadow(0 2px 2px rgba($primary, .4));

  ul {
    margin: 0;
    list-style: none;
  }

  li:not(.category):not(.heading) {
    font-size: 13px;
    line-height: 16px;

      .fa {
        margin-right: 3px;
      }

      a {
        display: block;
        padding: 5px;
      }

      &:hover a:not(.badge-notification) {
        background-color: scale-color($highlight, $lightness: 60%);
        }

      button {margin-left: 5px;}
  }

  .heading a:hover  {
    background-color: scale-color($highlight, $lightness: 60%);
  }

  .selected {
    background-color: scale-color($tertiary, $lightness: 90%);
  }


  // Notifications
  &#notifications-dropdown {
    .fa {
      color: scale-color($primary, $lightness: 50%);
    }
    li {
      background-color: scale-color($tertiary, $lightness: 90%);
      padding: 5px;
      &:hover a {background: transparent;}
    a {
      display: inline;
      padding: 1px;
      }
    }
    .read {
      background-color: $secondary;
    }
    .none {
      padding: 5px;
    }
    .loading {
      padding: 10px;
      display: block;
      color: scale-color($primary, $lightness: 50%);
      font-size: 24px;
      text-align: center;
    }
  }

  .category-links li:not(.heading) a {
    display: inline-block;
  }


  // Site map

  &#site-map-dropdown {
    .flagged-posts {
      display: inline-block;
      position: absolute;
      padding: 3px;
      margin-top: -22px;
      margin-left: 60px;
    }
    .heading {
      padding: 5px 5px 5px 0;
      a {padding: 0 5px;}
    }
  }

  // Search

  &#search-dropdown {
    .heading {
      padding: 5px 0 5px 5px;
    .filter {
      padding: 0 5px;
    }
     }
  }

  input[type='text'] {
    width: 93%;
    height: 22px;
    margin: 5px;
    padding: 5px;
  }

  .search-context {
    padding: 0 5px;
  }

  .searching {
    display: block;
    position: absolute;
    top: 17px;
    right: 15px;
    width: 22px;
    height: 22px;
    background: {
      image: image-url("spinner_96.gif");
      repeat: no-repeat;
      position: 0px 50%;
      size: 18px;
    };
  }
  .no-results {
    padding: 5px;
  }
  .filter {
    float: right;
    padding: 0;
    &:hover {background: transparent;}
  }

  // Categories

  .category {
    float: left;
    background-color: transparent;
    line-height: 20px;
    margin: 5px 5px 0 5px;
  }

  &#user-dropdown {
    width: 118px;
  }

  .btn {
    padding: 2px 8px;
    margin-bottom: 2px;
    .fa {
      margin-right: 5px;
    }
  }
}