不跳级地嵌套层级
按顺序从 h2 进入 h3，让大纲保持合理
不跳级地嵌套层级 是 CoddyKit 上的免费 Web Accessibility Academy 课时。 这是第 2 节课，共 4 节。 你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。 这是 Web Accessibility Academy 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 Web Accessibility Academy 课程共包含 4 节课。
本课时的部分内容尚未翻译，以英文显示。
Headings Form an Outline
Heading levels build an outline like a nested list. The level numbers tell users which sections sit inside which, just like an essay outline. 🌳
Go Down One at a Time
After an h2, a subsection uses h3, not h4. Increasing levels one step at a time keeps the structure honest and easy to follow.
<h2>Shipping</h2>
<h3>Delivery Times</h3>Skipping Down Breaks It
Jumping from h2 straight to h4 implies a missing h3. The outline now has a hole, and users wonder what they skipped.
Climbing Back Up Is Fine
You can leap back up any amount. After an h4, returning to h2 simply means a new top-level section started. That is allowed.
<h2>Payment</h2>
<h3>Cards</h3>
<h4>Visa</h4>
<h2>Returns</h2>Levels Mean Hierarchy
Each step down means contained within. An h3 is part of the h2 above it, not a sibling. The number is a relationship, not a size.
Do Not Choose by Looks
Never pick h4 just because you want smaller text. Choose the level the structure needs, then style the size with CSS.
Siblings Share a Level
Sections at the same depth share a heading level. Three equal subsections under one topic should all be h3, side by side.
<h2>Menu</h2>
<h3>Starters</h3>
<h3>Mains</h3>
<h3>Desserts</h3>Start Below the h1
Your first section heading is h2, sitting just under the single h1. The outline grows downward from that one root.
Deep Nesting Is Rare
Most pages stop around h3 or h4. If you reach h6 often, your content may need splitting into simpler, shallower sections.
Empty Levels Confuse
Do not add an h3 with no content under it just to reach a level. Every heading should introduce real material below it.
Test by Reading Numbers
Read your headings aloud as just their numbers. A smooth 1, 2, 3, 2, 3 flows; a sudden 2 to 4 reveals a skipped level.
Quick Check
You have an h2. What is the correct level for a subsection inside it?
Recap
You learned to step heading levels down one at a time, never skip a level going down, and choose levels for hierarchy, not size. ✅
常见问题解答
「不跳级地嵌套层级」课时是免费的吗？
是的 — 「不跳级地嵌套层级」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 Web Accessibility Academy 课程的其余内容，请升级到 CoddyKit PRO。 Web Accessibility Academy 课程共包含 4 节课。
「不跳级地嵌套层级」这节课中我会学到什么？
按顺序从 h2 进入 h3，让大纲保持合理 你通过在浏览器中直接运行的动手代码来练习 Web Accessibility Academy，全天候 AI 导师会在你学习这节课的过程中回答你的问题。
学习 Web Accessibility Academy 需要有经验吗？
无需任何先前经验。CoddyKit 上的 Web Accessibility Academy 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。 这是第 2 节课，共 4 节。
「不跳级地嵌套层级」课时需要多长时间？
大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。
我能在这节 Web Accessibility Academy 课中编写并运行代码吗？
能。每节 Web Accessibility Academy 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。