Looking for a beautiful keepsake book to fill with 18 years of memories for my daughter

Hi! I’m looking for a notebook/journal for a long-term family project and I’m having a surprisingly hard time finding exactly what I want.

I’m making a memory book for my daughter that I’ll keep adding to for the next 18 years. Family members and friends will be leaving letters, little notes, memories, photos, drawings, birthday messages, funny stories, etc. in it over the years.

I want something that feels more like a beautiful heirloom book than a regular notebook.

My ideal requirements:

• 300+ pages — more is absolutely fine, 400–600 would be even better
• Completely blank/unlined pages
• Hardcover
• Good-quality, fairly thick paper — ideally 100–120 gsm or higher
• Large enough to comfortably write, draw and stick photos/things into. B5-ish or larger would be great, but I’m NOT limited by size.
• Preferably a sewn or otherwise durable binding
• Something that will still look and feel nice after being handled for 18+ years
• I’m open to leather, linen, cloth, minimalist hardcover, etc. — just not something that looks overly medieval/fantasy
• I’m located in Croatia/EU, so EU shipping would be a huge plus
• Budget is flexible for the right book

I’ve already looked at Etsy, Amazon.de and various stationery shops, but most of the 300+ page options are either lined, have very thin paper, or are too small.

If you own something that fits this description, or know a brand/bookbinder that makes them, I’d LOVE your recommendations!

Bonus points if it’s something you would genuinely trust to survive being used as a family keepsake for decades. ❤️