Nonparametric reconstruction of the late-time cosmic expansion history from CC data. Top: reconstruction of H(z) from CC data using the ANN method, compared with the fiducial ΛCDM model (black solid line). The shaded green and blue regions represent the 68% and 95% confidence intervals of the ANN reconstruction, respectively. Bottom: the corresponding comoving distance D_M(z) obtained from the best-fit H(z), with the 68% confidence region shown in green. Orange points denote the reconstructed BAO distances ﹩{D}_{M}^{(\mathrm{rec})}(z)﹩.