How to set the output size of slides to 1:1(square)?

[samko5sam]

Hello 😃

I'm wondering how to set slides size to 1:1.

I try to set size: 1:1 in markdown file, but slides size is still 16:9. 🤔

And I try to set <style> width:720px , output layout is 720x720px, but image file is 1280x720px, some part of image is blank fill with white

⬇️ markdown file

---
marp: true
theme: base
backgroundImage: url('https://marp.app/assets/hero-background.jpg')
paginate: true
size: 16:9
header: header
footer: footer
---

<style>
section{
  width: 720px;
}
</style>

# Slide title
> subtitle

⬇️ markdown file marp-cli output image

Is there any way to set? 😄 Thank you very much

[yhatt]

By a technical limitation, overriding width and height declarations for section elements through <style> is not working, as you have tried.

You can use custom slide size by using custom theme CSS.

/* @theme square */

@import 'default';

section {
  width: 720px;
  height: 720px;
}

---
theme: square
---

# Slide title

See a documentation of your using tool about how to apply a custom theme CSS: https://github.com/marp-team/marp-cli#use-custom-theme (Marp CLI) and https://github.com/marp-team/marp-vscode#use-custom-theme-css-%EF%B8%8F (Marp for VS Code)

[imflash217]

can we apply the height and width directive per page?
Can we have slides with different page sizes in the same deck?
Thanks

[imflash217]

I tried to do this with

<style scoped>
section {
	height: 1600 px;
	width: 1600 px;
}
</style>

Thought the available content size of the that slide changed, but while pdf-export & printing, it still breaks the slide in the original size (thus removing a lot of content during pdf-export & printing.

[yhatt]

It is determined one size per theme in Marpit.

— https://marpit.marp.app/theme-css?id=slide-size#:~:text=It%20is%20determined%20one%20size%20per%20theme%20in%20Marpit.

Marp cannot change the slide size in the middle of slides by custom class or CSS selector, because the slide size definition is required to be deterministic.