Taking a look at the control banner and I think these CSS changes would resolve the issues noted:

1. On .mc-modal-screen, add "overflow-y: scroll;" and remove "height: 100vh;". That height declaration is overriding "height: 100%;" and I don't think we want that.
2. On .mc-modal, change the width declaration to "width: 90%;". This gets overridden by a media query at 800px, which is no problem.

For the button issue noted in variant 006, I would recommend solving it by changing the styles on .mc-button to the following:

font-size: 18px;
line-height: 1.2;
width: 100%;
height: 100%;
max-width: 240px;

This could be add globally to all variations with monthly convert.

Change 552341 had a related patch set uploaded (by Cstone; owner: Cstone):
[mediawiki/extensions/DonationInterface@master] Add width to monthly convert modal and donate monthly button.

https://gerrit.wikimedia.org/r/552341

Change 552341 merged by jenkins-bot:
[mediawiki/extensions/DonationInterface@master] Add width to monthly convert modal and donate monthly button.

https://gerrit.wikimedia.org/r/552341

Hey @spatton this is deployed now. Could you test on your iphone? It looks okay on my LG.

Thanks @Cstone, I can confirm that the modal is now scrollable and works better on my iphone5, thank you! I am seeing an issue with the Donate Monthly button copy wrapping to a new line and being partially hidden if I select Yes, I'll donate monthly, but for another amount. Screenshot:

It doesn't look like @EWilfong_WMF's suggestions for .mc-button were implemented:

font-size: 18px;
line-height: 1.2;
width: 100%;
height: 100%;
max-width: 240px;

Agreed, @spatton. And to be clear, you can add this CSS to the .mc-button class and then I *think* you can get rid of the .mc-edit-amount .mc-button CSS altogether.

This looks good to me otherwise!

Change 553211 had a related patch set uploaded (by Cstone; owner: Cstone):
[mediawiki/extensions/DonationInterface@master] Add with to .mc-edit-amount for smaller screen resolutions.

https://gerrit.wikimedia.org/r/553211

Change 553211 merged by jenkins-bot:
[mediawiki/extensions/DonationInterface@master] Add with to .mc-edit-amount for smaller screen resolutions.

https://gerrit.wikimedia.org/r/553211

@spatton @EWilfong_WMF

I just deployed an update to this. I didn't make all the changes as it started messing up the button on the non responsive version.

I was able to replicate what the iphone SE looks like on Safari on my mac and this last change fixed the button there.

@spatton have you been able to test this?