discourse/app/assets/stylesheets/common/components/keyboard_shortcuts.css.scss

.topic-list-item td:first-child, .topic-post {
  border-left: 1px solid transparent;
}

.topic-list-item.selected td:first-child, .topic-post.selected {
  border-left: 1px solid $danger;
}

.topic-list-item.selected {
  background-color: inherit;
}

.keyboard-shortcuts-modal .modal-body {
  max-height: 500px;
}

#keyboard-shortcuts-help {
  ul {
    list-style: none;
    padding-left: 0;

    li {
      margin: 5px 0
    }

    b {
      color: #000;
      background: #eee;
      border-style: solid;
      border-color: #ccc #aaa #888 #bbb;
      padding: 2px 6px;
      border-radius: 4px;
      box-shadow: 0 2px 0 rgba(0,0,0,0.2),0 0 0 1px #fff inset;
      background-color: #fafafa;
      border-color: #ccc #ccc #fff;
      border-style: solid solid none;
      border-width: 1px 1px medium;
      color: #444;
      white-space: nowrap;
      display: inline-block;
    }
  }
}