Is national rail 16-25 card same as Trainline?

yes if you ordered one from trainline, its the same as doing it from national rail - if that makes sense!

oh okay haha
I bought one on trainline and when i see my card it has an orange background, with my pic, 16-25 literally same as national rail

i was confused because people said its cheaper to get tickets with national rail when its the same with trainline

Trainline charge a booking fee when you buy tickets. You can buy the same tickets from the train operating companies without the booking fee, either online or at a station.

Thank you
I can go into the station and buy a ticket using my Trainline railcard right?

You shouldn't need to produce your railcard when you buy the ticket. But you absolutely must be able to show the railcard while you're travelling.

From https://www.thetrainline.com/trains/great-britain/railcards/16-25-railcard:

If I buy a 16-25 Railcard with Trainline, can I use it with tickets bought elsewhere?

Yes. Although your Railcard will live in your Trainline App, it can still be used with tickets bought elsewhere.