Interactive visualizer for floating-point formats: FP4 E2M1, FP8 E4M3,
FP8 E5M2, FP16, and BF16.
Shows how a real input x rounds to each format, with a zoomed 1D map of rounding bins.
Each colored segment is the interval of reals that round to a single representable value.
Rounding mode: round-to-nearest, ties-to-even.