backlog-gantt-chart-styles.user.js

// ==UserScript==
// @name         Backlog Gantt Chart Styles
// @namespace    http://senta.me/
// @version      0.1.3
// @description  Add styled on Backlog.jp to show the ticket IDs
// @author       @__senta
// @match        https://*.backlog.jp/gantt/*
// @match        https://*.backlog.jp/ViewProjectGantt.action*
// @grant        none
// ==/UserScript==

;(function() {
  "use strict"

  const style = document.createElement("style")
  style.innerText = `
    .summary-link::after {
      content: attr(href);
      display: block;
      font-size: .6em;
    }
  `

  document.getElementsByTagName("head")[0].appendChild(style)
})()