gitlabhq/app/assets/stylesheets/commits.css.scss

/** Commit diff view **/
.diff_file {
  border:1px solid #CCC;
  margin-bottom:1em;

  .diff_file_header {
    padding:5px 5px;
    border-bottom:1px solid #CCC;
    background: #eee;
  }
  .diff_file_content {
    overflow:auto;
    overflow-y:hidden;
    background:#fff;
    color:#333;
    font-size: 12px;
    font-family: 'Courier New', 'andale mono','lucida console',monospace;
  }
  .diff_file_content_image {
    background:#eee;
    text-align:center;
    img {
      padding:100px;
      max-width:300px;
    }
  }
}

.diff_file_content{
  .old_line, .new_line {
    background:#ECECEC;
    color:#777;
    width:35px;
    float:left;
    padding: 0px 5px;
    border-right: 1px solid #ccc;
    text-align:right;
  }
}

pre.commit_message {
  white-space: pre-wrap;
  font-family: "Helvetica", sans-serif;
  color: #555;
  font-weight:bold;
  font-size:15px;
}