Get my head around Unity Rotations

Hey, im comming from a VFX background and have just started playing around with unity.
But i just can’t get my head around the whole rotation thing.

If i in unity take a plane, set the rotation to 270 , 0 , 0 the object rotates as it should facing the Z axis.
However if i want to now tilt the object say, 90 degrees. I can’t do it.
Putting 270 , 90 , 0 will rotate the object around the Y axis, and putting 270 , 0 , 90 will do the exact same thing.
While in any 3D application putting 270 , 90 , 0 would eighter tilt it in its own or the world Z axis.

So in java i have set up the following:

Transform.Rotate(Vector3.down * Input.acceleration.y);

This slowly rotates the object around the Z axis as i want, but i want to set a absolute rotation and not slowly make it rotate around its own axis (ie Rotate 90 degrees, and stop)

So i tried the following

transform.rotation = Quaternion.Euler(Vector3.down * Input.acceleration.y)

That just introduced the problem described earlier.

What am i doing wrong?

Not quite sure I’m getting your concern. The rotation is in world coordinates and they are applied simultaneously - so 270 rotates the object around the X axis (of the object without rotation) and 90 rotates it around the Y axis (of the object without rotation) at the same moment.

If you want to combine a sequence of rotations then put the plane inside an empty game object and set the rotations in the order you prefer.