time-line {
  display: block;
  position: relative;
  width: 100%;
  border: solid 1px rgb(200, 200, 200);
}
div.time-period:first-of-type {
  margin-top: 30px;
}

div.time-period {
  display: block;
  margin-bottom: 0.5em;
  background-color: rgb(100, 100, 100);
  color: white;
  text-align: center;
  margin-right: 5px;
  word-wrap: normal;
  padding: 5px 5px;
  font-size: 0.7rem;
  border-radius: 0 1rem 1rem 0;
  box-sizing: border-box;
  transition: background-color 0.2s ease;
  cursor: pointer;
}

div.time-period:hover {
  background-color: rgb(70, 70, 70);
}

div.time-period:last-of-type {
  margin-bottom: 0;
}

div.year-marker {
  transition: all 0.2s ease;
  cursor: pointer;
}

div.year-marker:hover {
  background-color: rgba(0, 0, 0, 0.3) !important;
  width: 3px !important;
  font-weight: bold;
  color: #000 !important;
}