HTML Academy · Lesson

Nested Lists and List Styling

Nest lists within lists and control their appearance.

Nested Lists and List Styling is a free HTML Academy lesson on CoddyKit — lesson 4 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the HTML Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.

Nesting Lists

Lists can be nested inside <li> elements:

<ul>
  <li>Frontend
    <ul>
      <li>HTML</li>
      <li>CSS</li>
      <li>JavaScript</li>
    </ul>
  </li>
  <li>Backend
    <ul>
      <li>Node.js</li>
      <li>Python</li>
    </ul>
  </li>
</ul>

Correct Nesting

The nested list must be inside a <li> element, not a direct child of <ul> or <ol>:

<!-- WRONG: nested ul as direct child of outer ul -->
<ul>
  <ul>   <!-- INVALID -->
    <li>Item</li>
  </ul>
</ul>

<!-- CORRECT: nested ul inside li -->
<ul>
  <li>
    Parent item
    <ul>
      <li>Child item</li>
    </ul>
  </li>
</ul>

Multi-Level Bullet Styles

Browsers apply different default bullets at each nesting level:

<ul>
  <li>Level 1 — disc (filled circle)</li>  <!--  • -->
  <ul>
    <li>Level 2 — circle (open circle)</li>  <!--  ○ -->
    <ul>
      <li>Level 3 — square</li>             <!--  ▪ -->
    </ul>
  </ul>
</ul>

Resetting with CSS

Override nested list styles with CSS:

ul, ol {
  list-style: none;
  padding: 0;
  margin: 0;
}

/* Style each level explicitly */
.nav > li > ul {
  padding-left: 1rem;
  list-style: disc;
}

Numbered Nested Lists

Nested ordered lists with different types:

<ol type="1">
  <li>Introduction
    <ol type="a">
      <li>Background</li>
      <li>Motivation</li>
    </ol>
  </li>
  <li>Methods
    <ol type="a">
      <li>Data collection</li>
    </ol>
  </li>
</ol>

CSS Counters for Custom Numbering

Custom hierarchical numbering with CSS counters:

ol {
  list-style: none;
  counter-reset: level1;
}
ol > li { counter-increment: level1; }
ol > li::before { content: counter(level1) '. '; }

ol ol {
  counter-reset: level2;
}
ol ol > li { counter-increment: level2; }
ol ol > li::before {
  content: counter(level1) '.' counter(level2) ' ';
}

Accordion Navigation Pattern

A nested list can become an expandable sidebar navigation:

<ul class="tree-nav">
  <li>
    <details>
      <summary>Frontend</summary>
      <ul>
        <li><a href="/html">HTML</a></li>
        <li><a href="/css">CSS</a></li>
      </ul>
    </details>
  </li>
  <li><a href="/backend">Backend</a></li>
</ul>

Spacing Nested Lists

Control visual indentation with CSS:

ul {
  padding-left: 1.5rem;  /* Controls indent at each level */
  margin: 0.5rem 0;
}

/* Tighter nested spacing */
ul ul {
  margin: 0.25rem 0;
  padding-left: 1.25rem;
}

list-style Shorthand Review

All list style properties combined:

/* Shorthand: type position image */
ul {
  list-style: square inside;
}

/* Longhand equivalents: */
ul {
  list-style-type: square;
  list-style-position: inside;   /* inside or outside */
  list-style-image: none;
}

Custom Icons as List Markers

Use SVG or emoji as list markers:

ul.checklist {
  list-style: none;
  padding: 0;
}

ul.checklist li::before {
  content: '✓ ';
  color: #22c55e;
  font-weight: bold;
}

/* Or with a background SVG */
ul.icon-list li {
  padding-left: 2rem;
  background: url('/icons/arrow.svg') no-repeat 0 0.2em;
  background-size: 1rem 1rem;
  list-style: none;
}

Accessibility of Nested Lists

Nested lists and screen readers:

Screen readers announce nesting level and item count
Deep nesting (4+ levels) is confusing — keep to 2-3 levels maximum
If using list-style: none on the outer list, add role="list"

Quick Check

Where must a nested list be placed inside an outer list?

Recap: Nested Lists

Nested list essentials:

Nest lists inside <li> — never directly in <ul>
Browsers default to: disc → circle → square per level
CSS counters enable custom hierarchical numbering
Keep nesting to 2-3 levels for usability
Use <details>+<summary> for expandable nested navigation

Frequently asked questions

Is the “Nested Lists and List Styling” lesson free?

Yes — the full text of “Nested Lists and List Styling” is free to read here on the web, and the HTML Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the HTML Academy course, upgrade to CoddyKit PRO.

What will I learn in “Nested Lists and List Styling”?

Nest lists within lists and control their appearance. You practise HTML Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.

Do I need any experience to start HTML Academy?

No prior experience is required. HTML Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 4 of 4, so you can start here or from the beginning and move at your own pace.

How long does the “Nested Lists and List Styling” lesson take?

Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.

Can I write and run code in this HTML Academy lesson?

Yes. Every HTML Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.

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