
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Given an acute triangle $\triangle ABC$ with internal angles $A$, $B$, and $C$, and two vectors $\overrightarrow{p} = (2-2\sin A, \cos A+\sin A)$, $\overrightarrow{q} = (\sin A-\cos A, 1+\sin A)$. If vectors $\overrightarrow{p}$ and $\overrightarrow{q}$ are collinear,  
(1) find the magnitude of $\angle A$;  
(2) when the function $y=2\sin^2 B+\cos\left(\frac{C-3B}{2}\right)$ reaches its maximum value, find the magnitude of $\angle B$.

Present the answer in LaTex format: \boxed{Your answer}
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