How did winning the Persian Wars affect Athens?

Answer 1

In the latter stages of the wars, it led an anti-Persian league (Delian League).

When peace was made it continued collecting the annual war funds from the league, by force where necessary, using them for a navy to collect the funds, and used the money to beautify Athens (Parthenon etc) and keep half its population on the public payroll.

Its strong fleed also allowed it to interfere in the affairs of cities outside the empire it had made out of the Delian League. This adventurism brought it into conflict with the other Greek states headed by Sparta - the Peloponnesian League - and resulted in the devastating Peloponnesian War, which ended in Athens being stripped of its empire and becoming a second rate power in the Greek world.
Athens converted the Delian League, which it had led against Persia in the latter stages of the war, into an empire of its own, and lived high on the proceeds mulcted from those city-states.

Answer 2

It left Athens with nearly 200 Greek city-states who were contributing money to the anti-Persian league which it led. Athens continued to extort the money to spend on itself, turning the league into an empire of its own. This money was spent on maintaining a superior fleet, on beautifying Athens and putting half of Athens on the public payroll. The fleet was used to collect the annual money paymentys, by force if necessary, and to dominate the Greek world.

The overconfidence from secure walls and a superior fleet led Athens to over-reach itself and become too-easily involved in the Peloponnesian ar with the Peloponnesian League led by Sparta, which it eventually lost, and it was stripped of its empire.

Athens did not win the Persian War. It was part of a coalition of 200 Greek city-states which it led in the latter stages of the 50-year war.

The ongoing war ended in 449 BCE when a peace was negotiated. Athens then converted the Delian League, which had been formed to oppose the Persian Empire, into an empire of its own, enforcing continuing collection of the war funds even though the war was over. It used this money to maintain its navy which enforced collection of the annual levy, and spent the rest on itself, glorifying the city and putting half its own people on the public payroll.

This strength encouraged the Athenians to stand over not only its empire which it had converted the League into, but also intervene in the affairs of other cities outside the League. This brought war with the Peloponnesian League led by Sparta. Athens lost the war, was stripped of its empire, and became a second rate power.

They opportunistically converted the Delian League which they had led against the Persians into an empire of their own, continuing to levy the war funds but spending them in themselves, glorifying the city and putting half their citizens on the public payroll.