Na první pohled je účet správný.

Because this is a fixed expression with na + accusative: na první pohled.

Here, první is the accusative singular form of první and pohled is a masculine inanimate noun whose accusative singular looks the same as the nominative.

This phrase works like an idiom and means at first glance / at first sight. In Czech, many expressions with na use the accusative when they express a kind of direction, target, or set phrase.

So:

• na první pohled = at first glance
• not na prvním pohledu in this sentence

The form na prvním pohledu would sound unnatural here.

It is accusative singular.

Why?

Because it goes with na in the expression na první pohled. The noun pohled is masculine inanimate singular, and the adjective první must match it.

So the phrase breaks down like this:

• na = on / at / for, depending on context
• první = first, here in accusative singular
• pohled = glance, look

Together: na první pohled.

Because účet is the subject of the sentence.

The structure is:

• Na první pohled = adverbial phrase
• je = is
• účet = the bill/account, subject
• správný = correct, adjective describing the subject

In Czech, the subject of a sentence is normally in the nominative case, so účet stays in nominative singular.

Because správný is an adjective, while správně is an adverb.

Here, the sentence says that the account/bill is correct, so Czech uses an adjective agreeing with účet:

• účet je správný = the account is correct

But správně would mean correctly, which describes a verb, not a noun:

• To je správně. = That is correct.
• Udělali to správně. = They did it correctly.

So in your sentence, správný is the right form because it describes účet.

Because it agrees with účet, which is:

• masculine
• singular
• nominative
• inanimate

The basic nominative singular masculine adjective ending here is -ý:

• správný účet = a correct bill/account
• účet je správný = the bill/account is correct

This is normal adjective agreement in Czech.

Yes. Czech word order is more flexible than English word order.

The neutral order here is:

• Na první pohled je účet správný.

But you could also hear:

• Účet je na první pohled správný.
• Správný je účet na první pohled. — possible, but marked and less natural in ordinary speech

Why the given order?

Starting with Na první pohled gives the sentence a natural topic frame: At first glance, ...

So the original sentence sounds very normal and idiomatic.

Yes, definitely.

It is a very common Czech expression, and it is best learned as a chunk:

• na první pohled = at first glance
• láska na první pohled = love at first sight

Even though you can analyze the grammar, it is useful to remember the whole phrase as a set expression.

It can mean either, depending on context.

Common meanings of účet include:

• bill / check in a restaurant
• account in banking
• invoice / statement in some contexts

In your sentence, účet správný most naturally suggests something like the bill/account is correct. Without more context, both bill and account are possible.

So the grammar does not change, but the exact English translation depends on the situation.

In the present tense, Czech normally keeps je in this kind of sentence:

• Účet je správný.

Unlike Russian, Czech usually does not omit the present-tense form of to be in standard sentences like this.

So:

• účet správný on its own would sound incomplete in normal standard Czech
• účet je správný is correct

A natural neutral stress would usually fall near the end:

Na první pohled je účet správný.

Often správný gets the main sentence stress, because it carries the key new information.

If you wanted to emphasize a different part, the stress could change. For example:

• emphasizing the first impression: Na první pohled je účet správný.
• emphasizing the thing being discussed: Na první pohled je účet správný.

But in ordinary neutral speech, the final adjective often carries the strongest stress.

In this sentence, pohled means a glance / look.

So na první pohled is literally something like on the first glance.

Compare:

• pohled = glance, look, view
• vzhled = appearance, looks
• pohled na město = a view of the city

In na první pohled, the word keeps its basic sense of glance/look, but the whole phrase functions idiomatically as at first glance.

Sometimes, but it is not exactly the same and it is less standard in this exact expression.

The most common set phrase is:

• na první pohled = at first glance

There is also:

• na první dojem = on first impression

But na první pohled is much more common and idiomatic in sentences like this one.

So for a learner, the safest choice is to remember:

• Na první pohled je účet správný.

The pattern is:

adverbial phrase + verb + subject + predicate adjective

More specifically:

• Na první pohled = adverbial phrase
• je = linking verb
• účet = subject
• správný = predicate adjective

So this is the same type of structure as:

• Dnes je počasí hezké.
• Podle všeho je plán dobrý.

It is a very common Czech sentence type: something is something/described in some way.