I've known Heroku for a long time, but never have a try to build with it. This time, I found a beautiful file indexer, h5ai, that requires PHP 5.5+, and Heroku is a perfect platform to build and host it.

近期，Adobe 和 Google 联合发布了思源宋体，给了我一个惊喜，终于有个可以放心使用的开源宋体了，而且字体设计得挺和我心意。

It's convenient to set up a comment system in Jekyll site with external social comment systems like Disqus or Duoshuo (多说). However, as you all know, Disqus was blocked in China and Duoshuo is going to shutdown. It's the time to rethink about the comment system (although I didn't get too many comments →_→), simple and controllable. And it becomes true with Firebase database.

By default, Jekyll 3 and above versions integrated with Rouge, a pure Ruby syntax highlighter which supports over 100 languages. Since Rouge themes are compatible with Pygments’s stylesheets, it’s nice for us to choose a favourable style.

笔记中遇到公式在所难免，使用 MathJax 可以方便地在网页中渲染这些公式，可一旦公式较多，页面加载起来就很慢，于是使用 KaTeX 加速公式渲染。