[Bug] Sticky rendering in Firefox

[kelunik]

Browser: Firefox (version)

Steps to reproduce

• Focus date input
• Scroll while keeping focus

Reproduction Link or Source Code

• https://mengxiong10.github.io/vue2-datepicker/index.html

Expected behavior

• Date dialog stays right below / above input field

Actual behavior

• Date dialog is displayed sticky and stays at a fixed position

[kelunik]

The cause for this seems to be that the scrolling element isn't body or html, but an inner div next to the popup. Not sure why it works in Chrome.

[mengxiong10]

v3.4.0 fixed it.

[kelunik]

Fix confirmed, thanks!