gitlab-org--gitlab-foss/app/assets/stylesheets/generic/timeline.scss

.timeline {
  list-style: none;
  padding: 20px 0 20px;
  position: relative;

  &:before {
    top: 0;
    bottom: 0;
    position: absolute;
    content: " ";
    width: 3px;
    background-color: #eeeeee;
    margin-left: 29px;
  }

  .timeline-entry {
    position: relative;
    margin-top: 5px;
    margin-left: 30px;
    margin-bottom: 10px;
    clear: both;


    &:target {
      .timeline-entry-inner .timeline-content {
        -webkit-animation:target-note 2s linear;
        background: $hover;
      }
    }

    .timeline-entry-inner {
      position: relative;
      margin-left: -20px;

      &:before, &:after {
        content: " ";
        display: table;
      }

      .timeline-icon {
        margin-top: 2px;
        background: #fff;
        color: #737881;
        float: left;
        @include border-radius($avatar_radius);
        @include box-shadow(0 0 0 3px #EEE);
        overflow: hidden;

        .avatar {
          margin: 0;
          padding: 0;
        }
      }

      .timeline-content {
        position: relative;
        background: $background-color;
        padding: 10px 15px;
        margin-left: 60px;

        img {
          max-width: 100%;
        }

        &:after {
          content: '';
          display: block;
          position: absolute;
          width: 0;
          height: 0;
          border-style: solid;
          border-width: 9px 9px 9px 0;
          border-color: transparent $background-color transparent transparent;
          left: 0;
          top: 10px;
          margin-left: -9px;
        }
      }
    }
  }

  .system-note .timeline-entry-inner {
    .timeline-icon {
      background: none;
      margin-left: 12px;
      margin-top: 0;
      @include box-shadow(none);

      span {
        margin: 0 2px;
        font-size: 16px;
        color: #eeeeee;
      }
    }

    .timeline-content {
      background: none;
      margin-left: 45px;
      padding: 0px 15px;

      &:after { border: 0; }

      .note-header {
        span { font-size: 12px; }

        .avatar {
          margin-right: 5px;
        }
      }

      .note-text {
        font-size: 12px;
        margin-left: 20px;
      }
    }
  }
}

@media (max-width: $screen-xs-max) {
  .timeline {
    &:before {
      background: none;
    }
    .timeline-entry .timeline-entry-inner {
      .timeline-icon {
        display: none;
      }

      .timeline-content {
        margin-left: 0;
      }
    }
  }
}