Topology of magnetic fields can be preferentially tangential for CC clusters. Top panel: Visualization of magnetic fields in a single TNG-Cluster halo at z = 0 (Halo 17440255) showing the central 40% of r_500c. The background color shows the magnetic anisotropy β_A in the xy-plane. Negative values (yellow) correspond to tangential magnetic fields and positive values (blue) correspond to radially oriented magnetic fields. The magnetic field directions, which appear as relief-like structures in the image, are overplotted in gray. The white circle marks the radius at which the magnetic anisotropy profile (bottom panel) has its minimum. Bottom panel: Radial profiles of magnetic field anisotropy parameter β_A at z = 0 for all halos in TNG-Cluster. Thin lines show individual halos, colored by CC state. The thick lines show the median profiles for SCCs (blue), WCCs (purple), and NCCs (orange). The shaded bands indicate the 95% confidence intervals of the medians. WCCs and NCCs show a flat profile at β_A ∼ 0, while SCCs exhibit a dip at ∼0.1r_500c with β_A < 0. This shows that WCCs and NCCs have primarily isotropic magnetic fields, while SCCs have preferably tangentially oriented magnetic fields in the vicinity of this radius (as indicated by the black arrow).