Finding two' s complement of a fractional binary number

Question

I want to find out 2's complement of binary number

(00101101.1100)

To find the 2's complement of a binary number, invert all bits (change 0s to 1s and 1s to 0s) and then add 1 to the result.

For the given binary number (00101101.1100)

1. Invert all bits: (11010010.0011)
2. Add 1: (11010010.0100)

On the book, they have given 2's complement of the binary number as (11010010.0100).

But should not (11010010.0011) + (1) give us (11010011.0011).

For example, in decimal number system when we add,

(10.008) + (2) = (12.008) and not (10.010)