Pop up Klaviyo: broken design on all devices + Email field not editable

Hey ​@jacinta,

This is a pretty common Klaviyo form frustration, especially with 2-column layouts. You’re not doing anything wrong, it’s just how the builder handles responsiveness.

1. Layout breaking on mobile / desktop
A 2-column popup will never behave like a fixed design. Klaviyo automatically reflows it based on screen width, so what you see in the editor is more of a “flexible suggestion” than a locked layout.

What I usually recommend (and what tends to solve this cleanly) is actually simple: build two separate forms.
One optimized for desktop, one for mobile.

• Desktop: you can keep the 2-column layout and visual hierarchy
• Mobile: go single-column, image stacked or even removed if needed

Then set display rules per device. It’s a lot more stable than trying to force one form to behave perfectly everywhere.

2. Email field not editable

This is normal. The email input field is a system element inside Klaviyo forms, not a fully custom block. That means you can’t style it like a normal text box.

You can still control it, just not directly in the way you’re trying. Instead:

• Go to the form’s Styles tab (not the block itself)
• There you control global input styling (border, radius, padding, font, etc.)

3. About CSS
I’d only bring CSS in if you’re trying to do something Klaviyo literally doesn’t support (rare for popups). For what you’re describing, I don't think it’s necessary.

I hope this helps!