Create a clear classroom cutaway illustration showing how a stratovolcano erupts. Center one volcano in a horizontal 4:3 composition and devote the lower half to the underground cross-section. Show a connected magma chamber, main conduit, branching side vent, layered rock strata, summit crater, ash column, falling tephra and a lava flow descending the slope. Make every geological relationship readable through shape and color alone, using muted earth layers, deep red and orange magma, gray ash and a pale cool-blue background. Polished educational editorial illustration with accurate simplified geology, crisp cutaway surfaces and a subtle paper texture, friendly for middle-school science. No people, labels, letters, numbers, legend, long arrows, logo or watermark; no fantasy creature, no photoreal disaster and no disconnected pipes.