Strong rule: style --- 3D Pixar ---. 3D Pixar style. Close-up of the green chalkboard. The professor's hand points to the large, clear formula written in white chalk: 'a x² + b x + c = 0'. Below it, written in yellow chalk: 'a ≠ 0'. No English words. Bright classroom lighting.
Character appearance reference (MUST match exactly):
- Профессор Архимед: A friendly, energetic math professor in 3D Pixar style. He has messy white hair, round glasses, a neat beard, wearing a tweed jacket with elbow patches and a bright bow tie. Expressive face, warm smile, animated gestures.
