.archive-tree-block details,
.archive-tree-block .archive-tree-year,
.archive-tree-block details > summary.archive-tree-year {
  margin-top: 0;
  margin-bottom: 0;
  padding-top: 0;
  padding-bottom: 0;
}
.archive-tree-year {
  font-weight: normal;
}
.archive-tree-month-list {
    margin: 0;
    padding-left: 2em;
}
.archive-tree-month {
  margin-left: 0;
  padding-left: 0;
  border-left: 2px solid #ccc;
  display: block;
}