Creative Ways to Style the HTML `<details>` Tag

The HTML <details> element is a powerful semantic tag that creates an interactive disclosure widget. Users can click to show or hide additional content, making it perfect for FAQs, expandable content sections, footnotes, and more. Combined with the <summary> element, it provides native browser functionality for collapsible content without requiring JavaScript.

Understanding the <details> Element

The <details> element consists of two main parts:

• <summary>: The clickable header that's always visible
• Content: The collapsible content that shows/hides when clicked

Basic syntax:

<details>
  <summary>Click to expand</summary>
  <p>This content can be toggled!</p>
</details>

The <details> element supports several useful attributes:

• open: Makes the details expanded by default
• name: When using the same name for several elements, the user can open only one dialog box at the time

5 Creative Styling Examples

Let's explore five different approaches to styling the <details> element, each demonstrating unique design patterns and techniques.

1. Simple FAQ Accordion with <details> Tag

This first demo creates a clean FAQ-style accordion with custom arrow indicators and visual feedback.

Tips:

• Use summary::-webkit-details-marker { display: none; } to hide default browser markers
• The details[open] selector targets the expanded state
• CSS transforms create smooth arrow animations
• Flexbox in the summary ensures proper spacing between text and arrow

2. <details> tag with Outside Marker

This demo showcases the native browser marker positioned outside the summary content, along with the exclusive accordion functionality using the name attribute.

Tips:

• list-style-position: outside moves the marker outside the content box
• The name="requirements" attribute enables exclusive accordion behavior - clicking one summary will automatically close any other open details with the same name
• summary::marker allows styling of the native disclosure triangle

3. Custom Emoji Markers for <details> Summary (Open/Closed States)

This demo uses emoji as custom markers that change based on the open/closed state, perfect for thematic content.

Tips:

• Use summary::marker { content: "emoji"; } to replace the default marker
• The details[open] selector changes the marker when expanded
• This technique works with any Unicode character or emoji
• Keep the content thematically relevant to your design

4. 4 CSS Styling Variations for HTML <details> element

This comprehensive demo showcases four distinct styling approaches, each with different visual indicators and design patterns.

Style Variations:

1. Triangle Arrow: Classic dropdown arrow using CSS borders
2. Up/Down Arrow: Rotated up arrow that becomes a down when open
3. Cross Style: Plus sign that removes the vertical line when expanded
4. Inline Tooltip Style: Compact design for inline expandable content

Tips:

• Use CSS borders to create geometric shapes for indicators
• Absolute positioning allows precise control over custom markers
• The display: none technique can hide elements in the open state

5. HTML <details> Tag for Simple Footnotes

This innovative demo transforms the <details> element into an interactive footnote system, perfect for academic or reference content.

Tips:

• display: inline-block allows the details to flow with text
• vertical-align: super creates the superscript effect
• Fixed positioning with transforms centers the footnote content
• name="footnote" creates exclusive behavior for multiple footnotes

Best Practices and Advanced Tips

Accessibility Considerations

• Ensure sufficient color contrast
• Test with keyboard navigation
• Consider screen reader compatibility

Performance Tips

• Use CSS transitions for smooth animations
• Avoid complex JavaScript when CSS can achieve the same effect
• Optimize for mobile touch interactions

Browser Compatibility

• The <details> element is well-supported in modern browsers
• Always test across different browsers for consistent behavior
• Consider progressive enhancement for older browsers

Advanced Techniques

• Use CSS custom properties for theme consistency
• Implement ARIA attributes for enhanced accessibility

Conclusion

The HTML <details> element offers a powerful, semantic way to create interactive content without JavaScript. From simple FAQ accordions to innovative footnote systems, these examples demonstrate the versatility of this often-overlooked HTML element. By combining thoughtful CSS styling with the native functionality of <details>, you can create engaging, accessible user interfaces that enhance the user experience while maintaining clean, semantic markup.