.forum {
  ul.breadcrumb {
    .dropdown-menu {
      max-width: inherit;
    }
  }

  .post {
    // In case the previous post was too short.
    clear: both;

    .user {
      text-align: right;
      float: left;
    }

    .contents {
      // Same as .thumbnail from Bootstrap 2.2.
      padding: 20px;
      line-height: 1;
      border: 1px solid #ddd;
      -webkit-border-radius: 4px;
      -moz-border-radius: 4px;
      border-radius: 4px;
      -webkit-box-shadow: 0 1px 1px rgba(0, 0, 0, 0.075);
      -moz-box-shadow: 0 1px 1px rgba(0, 0, 0, 0.075);
      box-shadow: 0 1px 1px rgba(0, 0, 0, 0.075);

      // Block formatting context
      overflow: hidden;
    }
  }

  .thread {
    padding-left: 75px;
  }
}

.forum {
  ul.breadcrumb {
    .dropdown-menu {
      max-width: inherit;
    }
  }

  .post {
    // In case the previous post was too short.
    clear: both;

    // Spacing between posts.
    margin-bottom: 1em;

    .user {
      margin-right: 1em;
      text-align: right;
      float: left;
    }

    .contents {
      // Same as .thumbnail from Bootstrap 2.2.
      padding: 20px;
      line-height: 1;
      border: 1px solid #ddd;
      -webkit-border-radius: 4px;
      -moz-border-radius: 4px;
      border-radius: 4px;
      -webkit-box-shadow: 0 1px 1px rgba(0, 0, 0, 0.075);
      -moz-box-shadow: 0 1px 1px rgba(0, 0, 0, 0.075);
      box-shadow: 0 1px 1px rgba(0, 0, 0, 0.075);

      // Block formatting context
      overflow: hidden;
    }
  }

  .thread {
    padding-left: 75px;
  }
}

Fix the spacing between posts.
Fix the spacing between posts.
