.timeline {
  --date_column_width: 80px;
  --timeline_column_width: 60px;
  --timeline_line_width: 6px;
  --timeline_line_color: #444;
  --timeline_bullet_diameter: 25px;
  --timeline_bullet_border_width: var(--timeline_line_width);
  --timeline_bullet_color: #FFF;
  --content_collapse_duration: 0.3s;
  --content_background_color: #FFF;
  --content_border_color: #444;
  --content_duration_color: #000; }

.timeline {
  position: relative;
  margin: 0 auto; }
  .timeline::after {
    content: "";
    position: absolute;
    width: var(--timeline_line_width);
    background-color: var(--timeline_line_color);
    top: 0;
    bottom: 0;
    left: calc(var(--date_column_width) + 0.5*var(--timeline_column_width) - 0.5*var(--timeline_line_width)); }
  .timeline .container {
    margin-bottom: 0px;
    position: relative;
    width: calc(100% - var(--date_column_width) - var(--timeline_column_width));
    margin-left: calc(var(--date_column_width) + var(--timeline_column_width)); }
    .timeline .container::after {
      content: "";
      position: absolute;
      width: var(--timeline_bullet_diameter);
      height: var(--timeline_bullet_diameter);
      left: calc(-0.5 * var(--timeline_column_width) - 0.5 * var(--timeline_bullet_diameter) - var(--timeline_bullet_border_width));
      background-color: var(--timeline_bullet_color);
      border: var(--timeline_bullet_border_width) solid var(--timeline_line_color);
      top: 0px;
      border-radius: 50%;
      z-index: 1; }
    .timeline .container .date {
      position: absolute;
      width: var(--date_column_width);
      top: 22px;
      z-index: 1;
      left: calc(-1 * (var(--date_column_width) + var(--timeline_column_width)));
      font-size: large;
      line-height: 1.0em;
      text-align: end;
      margin: 0px; }
  .timeline .content {
    border: 2px solid var(--content_border_color);
    background-color: var(--content_background_color);
    position: relative;
    border-radius: 6px;
    transition: box-shadow 0.3s; }
    .timeline .content:hover {
      box-shadow: 0 0 3px 3px #0004; }
    .timeline .content .title {
      padding: 5px 30px;
      font-weight: bold;
      display: inline-block; }
    .timeline .content .duration {
      margin: 0;
      color: var(--content_duration_color);
      opacity: 0.6;
      position: absolute;
      top: 50%;
      transform: translateX(-50%) rotate(-90deg);
      transform-origin: 50% 100%;
      width: auto;
      transition: opacity calc(0.5 * var(--content_collapse_duration));
      transition-delay: calc(0.5 * var(--content_collapse_duration)); }
    .timeline .content.collapsed .duration {
      opacity: 0.0;
      transition-delay: 0.0s; }
    .timeline .content .body {
      margin: 0px;
      padding: 5px 30px;
      transition-property: max-height, padding;
      transition-duration: var(--content_collapse_duration);
      transition-timing-function: ease-in-out;
      overflow: hidden; }
    .timeline .content.collapsed .body {
      padding-top: 0px;
      padding-bottom: 0px;
      max-height: 0px; }