ion-fab-list not perfectly aligned with ion-fab-button

[websystems-dev]

Fist of all: great job!

I spotted a design bug. When a FAB list list is expanded, alignment with the main open/close ion-fab-button seems wrong.
See my screenshot (directly from the demo page at https://ionic-theme-ios26.netlify.app/main/index/floating-action-button )

I added green and blue borders just to visualize the gap.

There are two cases:

1. When the size of the main ion-fab-button is "small": adding a margin-inline-start: 4px; to the ion-fab-list will align them perfectly
2. With a big main button (as in the screenshot): adding a margin-inline-start:2px to ion-fab-list aligns "more or less" these elements. I say "more or less" because there will be always a 1px gap: the big button width is 61px and the list is 56px (so no pixel-perfect alignment is possible).

Same for horizontal FABS (top margin missing).

[rdlabo]

Thank you for the detailed report, measurements, and visual explanation.

We confirmed the cause. The theme changes the main FAB dimensions to 61 by 61 pixels and the small FAB to 48 by 48 pixels, while Ionic’s ion-fab-list layout still uses its own 56-pixel minimum size as the positioning reference. As a result, the list and the main button do not share the same center:

• The default button is offset by approximately 2.5 pixels.
• The small button is offset by 4 pixels because of its dimensions and margins.

Rather than adding separate fixed margins for each button size, we should align the list geometrically:

• Lists opening to the top or bottom should be centered on the FAB’s horizontal center.
• Lists opening to the start or end should be centered on the FAB’s vertical center.

This approach also covers large buttons, fractional pixel differences, and RTL layouts without accumulating size-specific adjustments.

We’ll add open-state visual-regression cases for all four list directions with default, small, and large FAB buttons in light and dark modes. The current snapshots only capture the lists while closed, so they cannot detect this regression.

We’ll keep this Issue open until the alignment and visual coverage are corrected. Thank you for identifying the underlying dimensions so precisely.