وَالصِّرَاطُ حَقٌّ
The Sirat is real.
The Sirat is described as a bridge extended over Hell, to be crossed on the way to Paradise. Traditional descriptions include «أَدَقُّ مِنَ الشَّعْرِ وَأَحَدُّ مِنَ السَّيْفِ»—finer than a hair and sharper than a sword—conveying the gravity of the crossing.
The central affirmation and the particular details of the bridge are different levels of knowledge. We accept what is transmitted without pretending that worldly engineering fixes every feature of an unseen reality.