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I recently bought a domain and pointed it at my GitHub Pages site. It sounds like a one-click thing, but it comes down to two little DNS records: an A record and a CNAME record. Once I understood what each one does, the whole process stopped feeling like magic. Here’s the explanation I wish I’d had. A 30-Second DNS Refresher When someone types example.com into a browser, computers don’t actually understand names — they only talk to IP addresses (like 185.199.108.153). DNS (Domain Name System) is the giant phone book that translates a human-friendly name into a machine-friendly address. ...

这是一篇按日期累积的开发日志。每次改动博客，我都把"做了什么"和"学到的前端原理"记在这里，方便以后翻查。最新的改动放在最上面。 维护约定：下次改动时，在 改动模板 上面新增一个 ## 日期 — 标题 小节即可。 2026-06-09 — 接入自定义域名 + 翻译按钮升级 这次做了什么 自定义域名上线：把 GoDaddy 买的 xungirl.com 接到 GitHub Pages，配置了 DNS（4 条 A 记录指向 GitHub IP + 1 条 www 的 CNAME），清掉了 GoDaddy 默认的停放记录，最后开启了自动 HTTPS（Let’s Encrypt 证书）。 新增文章：一篇讲 A 记录 vs CNAME 记录的英文文章。 翻译按钮：保护代码与公式：点翻译时，代码块、行内代码、数学公式保持原样不被翻译。 翻译按钮：升级为双向：自动判断当前文章是中文还是英文，翻成"另一种"——英文文章翻中文、中文文章翻英文。 涉及文件：layouts/partials/extend_head.html（翻译逻辑）、content/posts/（文章）。 前端原理 这次最值得记的是几个前端基础概念，比具体代码更重要。 1. 构建期 vs 运行期（最核心的一条线） 构建期（Hugo） 运行期（浏览器 JS） 谁在做 push 后 GitHub Actions 构建一次，生成静态 HTML 访客打开页面时，浏览器实时执行 适合 文章内容、菜单、固定文案（可走 Hugo 的 {{ i18n }} 翻译） 会动的东西：计时器、实时翻译、交互 特点 生成完就定死，之后不变 每次访问都重新跑，可以随时变 为什么重要：博客底部那个"已运行 X 天 X 时"的计时器，必须用运行期 JS（因为每秒都在变，Hugo 构建一次没法让它跳动）；而它显示的英文字是写死在 JS 里的，脱离了 Hugo 的翻译体系，所以切语言不会变——这不是 bug，是它本来就在另一套系统里。 ...

This post documents the full history of changes to this blog. Partly for my own reference, partly because I think the process of setting up a dev blog is underrated as a learning exercise. Initial Setup — Feb 2026 Started with Hugo + the PaperMod theme. The decision was straightforward: Hugo is compiled Go, so builds are near-instant even with lots of posts PaperMod has clean typography, dark mode, math support, and search out of the box GitHub Pages + GitHub Actions = free hosting with automatic deploys on every push The deploy pipeline in .github/workflows/deploy.yml is about 20 lines: ...

“Agent” is one of the most overloaded words in AI right now. Everything from a simple function-calling wrapper to AutoGPT gets called an agent. This post cuts through the hype and explains the actual mechanics: how agents think, act, and plan, with the math to back it up. What Is an Agent? A bare LLM is a function: given a prompt, output a completion. An agent wraps that function in a loop: ...

The 2017 paper Attention Is All You Need changed NLP forever. Before it, sequence models meant RNNs or LSTMs — sequential, slow, and bad at long-range dependencies. The Transformer threw all of that out and replaced it with pure attention. This post walks through the key components with the actual math. The Problem with RNNs An RNN processes tokens one at a time. To compute the hidden state at step $t$, you need the state at $t-1$: ...

Welcome Hi, I’m Jiaju — a CS student at Northeastern University. This blog is where I share what I learn about programming, algorithms, and software engineering. Why I Started This Blog Writing helps me think more clearly. By explaining concepts in my own words, I understand them better. Plus, it’s a great way to track my learning journey. A Quick Math Demo The time complexity of merge sort can be expressed as: ...