Trade mark fixed on column with background image? (fully responsive)

Hey there ! Augustine Mak 👋
I'd really appreciate your thoughts on this!

I've been trying to get this working properly for 3 days now and I’m still not satisfied.
Here's the setup: I have a 3-column layout. Each column has a background image with 70% opacity.

Now, I want to add a logo at the bottom right corner of the third column. Here's what I’ve tried so far:

1. Added an image directly to the column and positioned it using the position settings.
2. Tried applying it as a background image to the column with z-index adjustments.
3. Created an extra row, inserted the logo there, and tried moving it with margins and padding.

But none of these solutions feel clean or responsive enough.
So here I am, asking for your expert advice — how would you approach this?

Thanks so much! 🙏