First trip to Europe (25 days) - Any recommendation?

Hello, I'm planning a trip to Europe with my girlfriend in February-March 2026.

We will be flying from Mexico to Madrid on February 12th, arriving at 6:50 PM. The return flight is from Madrid to Mexico on March 8th, departing at 4:30 PM. I should mention that we will be traveling light.

The itinerary we have organized so far looks like this:
* Madrid (12–15 feb / 4 days)
* 16 feb: Madrid → Roma (flight ~ 2h30)
* Rome (16–19 feb / 4 days)
* 20 feb: Roma → Florencia (train ~ 1h30)
* Florence (20–21 feb / 2 days)
* 22 feb: Florence → Milan (train ~ 2h)
* Milan (22 feb / 1 day)
* 23 feb – Excursion to the Alps - returning to Zurich to take a Nightjet to Amsterdam ~12h *** (1 day)
* Amsterdam (24–27 feb / 4 days)
* 28 feb: Amsterdam → Brussels (train ~ 2h)
* Brussels (28 feb – 1 mar / 2 days)
* 2 mar: Brussels → Paris (train ~ 1h30)
* París (2–5 mar / 4 days)
* 6 mar: Paris → Barcelona (train ~ 6h30)
* Barcelona (6–8 mar / 3 days)
* 8 mar – Last day - Barcelona → Madrid (train ~ 2h30) - Flight Madrid → Mexico.

What do you think about the itinerary?
Would be glad to hear some advices, thank you.