What could be causing the z-index issues with a sticky header in Safari and iOS Safari, while it works correctly in Chrome, and how can it be resolved using Webflow?

A sticky header z-index issue in Safari or iOS Safari that doesn’t occur in Chrome likely results from differences in how Safari renders position: sticky with stacking contexts. Here's how to troubleshoot and resolve this in Webflow.

1. Understand Safari-Specific Z-Index Behavior

• Safari handles stacking contexts differently than Chrome, especially when sticky elements are wrapped inside containers with overflow, transform, or will-change.
• A parent element with overflow: hidden or transform set can create a new stacking context that traps the sticky element, causing it to appear below siblings or other elements unexpectedly.

2. Inspect the Header's Parent Elements

• In Webflow’s Navigator panel, check the hierarchy of your sticky header.
• Examine if any parent elements have overflow: hidden, overflow: scroll, will-change, transform, filter, or perspective styles applied.
• These should be removed or altered because they create new stacking contexts, which influence how z-index works.

3. Check Header and Other Elements’ Z-Index Values

• Select your sticky header and check its Z-index in the Style panel. Assign it a high value like Z-index: 9999 to ensure it stacks above other elements.
• Verify that background and sibling sections don’t have overlapping z-index values or stacking context issues.
• If you're using position: sticky, Safari may still misbehave unless the direct sticky element has a stacking context. To help:
• Add position: relative explicitly to the sticky element.
• Avoid using sticky inside elements using overflow: hidden when possible.

4. Adjust The Sticky Position in Webflow

• In the Style panel, confirm the header is set to position: sticky with top: 0 set.
• Confirm the header is not nested too deeply; sticky works best on elements close to the body or main layout wrappers.

5. Use Custom Code or Fallback Options (If Needed)

• If you're still facing issues, consider using a fixed position for the header instead of sticky. Safari typically handles position: fixed more consistently.
• Alternatively, try triggering a layering fix using opacity or transform animation on scroll using Webflow Interactions. This can force a repaint that sometimes solves Safari rendering issues.

Summary

Safari may mishandle z-index of sticky elements if affected by stacking contexts created by parent styles like overflow: hidden or transform. Remove these properties from parents, assign an explicit high z-index to the sticky header, and set it as position: relative with top: 0. Switching to position: fixed can also be a reliable fallback.