Simulated spectral features compared to HST observations taken from Edwards et al. (2021), assuming H₂ -dominated atmospheres. The scenarios are color-coded: solid blue line for the low CH₄ scenario (1a), as shown in Fig. 5, and solid purple line for scenario 1a, but with an assumed constant H₂O mixing ratio of 1%; solid green line for the medium CH₄ scenario (1b); solid and dashed orange lines for the high CH₄ scenario (1c) with thin and thick hazes, respectively. All spectral data were binned to R = 300 and subtracted from the mean transit depth between 1.1 and 1.7 μm.