A progressive disclosure accordion built with pure HTML and CSS that reveals content panels incrementally based on user interaction. It supports controlled information layering to reduce cognitive load and improve readability.
Usage
Use this component when interfaces require step based content revelation, such as onboarding guides, documentation breakdowns, multi step explanations, or FAQ sections that benefit from gradual information exposure.
Implementation
The accordion behavior is implemented using CSS state selectors and transition based height control, allowing sections to expand smoothly without JavaScript. Structured grouping ensures clear hierarchy and responsive stacking across devices.
HTML
<div class="accordion-progressive">
<button class="accordion-trigger">
Details
</button>
<div class="accordion-panel">
<div>
<p>
This content reveals smoothly on hover.
</p>
</div>
</div>
</div>CSS
.accordion-progressive {
width: 220px;
background: #ececec;
border-radius: 16px;
padding: 6px;
box-shadow:
0 8px 20px rgba(0, 0, 0, 0.08),
inset 0 1px 0 rgba(255, 255, 255, 0.6);
font-family: system-ui, -apple-system, sans-serif;
}
.accordion-trigger {
width: 100%;
padding: 0.7rem;
border-radius: 12px;
border: none;
background: linear-gradient(180deg, #ffffff, #f3f3f3);
color: #1f2937;
font-size: 13px;
font-weight: 500;
cursor: pointer;
transition:
background 200ms ease,
transform 120ms ease,
box-shadow 120ms ease;
}
.accordion-trigger:hover {
background: #ffffff;
transform: translateY(-1px);
box-shadow: 0 4px 10px rgba(0, 0, 0, 0.08);
}
.accordion-panel {
display: grid;
grid-template-rows: 0fr;
opacity: 0;
transition:
grid-template-rows 260ms ease,
opacity 180ms ease;
}
.accordion-panel > div {
overflow: hidden;
padding: 0 0.8rem;
color: #374151;
font-size: 12px;
line-height: 1.5;
}
.accordion-progressive:hover .accordion-panel {
grid-template-rows: 1fr;
opacity: 1;
}
.accordion-progressive:hover .accordion-panel > div {
padding: 0.6rem 0.8rem 0.8rem;
}Notes
- Built with pure HTML and CSS
- No JavaScript required
- Supports progressive content disclosure
- Enhances information clarity and focus
- Fully responsive across breakpoints
- Suitable for onboarding and documentation
- Easy to customize animation timing and spacing
Preview styles shown. Production customization recommended.
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