Email compatibility

The exported HTML is built for email clients, not browsers: it uses tables with inline styles, avoids flex/grid/position, and adds conditional ghost tables for Outlook (Word engine).

Techniques used

• Presentation tables (role="presentation") for all layout — columns, padding, alignment.
• MSO ghost tables (<!--[if mso]>...<![endif]-->) so Outlook desktop computes pixel widths where other clients use %/max-width.
• A single media query to stack columns on mobile (@media (max-width: 480px)) and for the per-device hide classes.
• VML (<v:roundrect>) on fixed-width buttons, to get rounded corners in Outlook desktop too — the only way to achieve that there.
• font-size:0;line-height:0 on dividers and separators, to avoid the whitespace gap that display:inline-block leaves in inline layout.

Known limitations

• Doesn't import existing HTML — JSON only (your own, or Unlayer's).
• Row backgrounds: partial support in Outlook desktop (no full-bleed VML yet).
• Merge tags are emitted as — your sending platform's engine replaces them; the library interpolates nothing.
• Columns can't be reordered within a row (rows and blocks can be reordered).
• theme only accepts 'light' | 'dark' (no 'auto').
• Column border/radius: supported in the model and the exported HTML, but no dedicated inspector control yet.
• The Image block's borderRadius uses CSS border-radius — looks right in the builder and in most clients, but Outlook desktop (Word engine) ignores it.
• The timer doesn't animate without an integrator-provided dynamic image service — without one, it shows a static box with the days remaining.

See also

• Backgrounds — background image/color per row and column.
• Importing from Unlayer — what gets warned about when converting a template.