数学奇迹：沙漠中的古老符号遗迹

A 2x2 grid of 4 monumental mathematical symbols built as ancient desert ruins in sandstone [Top Left: The Integral (∫) as a collapsed arch-aqueduct, wind-eroded blocks, carved microtext equations, tiny caravans for scale] [Top Right: The Sigma (Σ) as a stepped fortress-ziggurat with sharp terraces, long shadows, sand drifts collecting in corners] [Bottom Left: The Pi (π) as two colossal pylons and a lintel bridge over a narrow oasis canal, chipped stone, scattered rubble geometry] [Bottom Right: A Penrose Triangle as impossible ruins half-buried in dunes, optical illusion architecture, impossible-geometry perspective, sunlight slicing across paradox edges] Aerial oblique view, golden desert haze, crisp hard sunlight, dramatic shadows, photoreal ruins texture, subtle river ribbon, swiss 2x2 grid layout.