sticky-header

July 8, 2026 · View on GitHub

When To Use

Use this pattern when you need to keep a header visible above a scrolling content region.

HTML

<header class="sticky_header">
    <nav aria-label="Repository"><a href="#">Code</a><a href="#">Issues</a><a href="#">Pull requests</a></nav>
</header>

CSS

.sticky_header {
    inset-block-start: 0;
    position: sticky;
    z-index: 1;
}

Core Properties

inset-block-start, position, z-index define the spatial behavior for this pattern.

Properties That Break The Layout If Removed

Removing inset-block-start, position, z-index changes the pattern from its documented layout responsibility back toward ordinary flow or an unsafe fixed arrangement.

Constraints And Change Points

fluid responsiveness is part of the contract; change sizing values only when the new minimum, maximum, or wrap point is documented with the pattern.
Keep the HTML class hooks and CSS selectors in one-to-one agreement.

Accessibility And Source Order Notes

Semantic role expectation: Preserve the HTML sample's landmark, list, navigation, form, figure, or article roles; layout classes must not replace semantic elements.
DOM order expectation: Keep semantic elements, DOM order, reading order, and focus order independent from the visual placement created by the layout classes.
Focus risk: Any interactive descendants follow DOM order; do not use this pattern to create a visual order that keyboard focus cannot follow.
Scroll expectation: No internal scroll container.
Cognitive risk: Low: the pattern should preserve ordinary reading flow when semantic order is already correct.

The CSS uses modern grid, flex, intrinsic sizing, logical properties, or positioning. If a target browser cannot support a property, fall back to ordinary block flow before adding decorative or script-driven layout behavior.

Composition Notes

Use sticky_header as the stable pattern root and compose additional layout behavior outside that root unless the child class is part of the documented relationship.

Anti-patterns

Do not add color, border, shadow, typography, or animation rules to reusable pattern CSS.
Do not use this pattern to repair unclear HTML structure; make the DOM roles legible first.

Parent: Viewport / Shell patterns in Pattern Categories. Next: Layout Recipes for screen-level composition, or return to the Layout Pattern Catalog when choosing another primitive.