Hi, this isn't an expected behavior, but I can't recreate it on my end and I've never heard of anyone else experiencing it! Pressing 'C' on the keyboard does bring up the codex as a keyboard shortcut--could your specific keyboard/mouse settings have a command or shortcut tied to long-pressing the left mouse button?
Thank you for your help.I'm a complete computer idiot, so I don't think I've ever set up anything like that. I tried switching to a different mouse or using the touchpad, but neither worked T_T
Since I couldn't fix the issue, I've decided to just ignore it. ;)
Also, I really love your rich world-building and beautiful writing（they're amazing!）
Thank you so much for your kind words, I'm honored to hear you're enjoying the game!! Sorry about that behavior, I'll try to make a mental note to investigate it when I'm back from vacation in the future. If you feel like submitting an official bug report through the form linked in the game description, that will ensure I remember, but otherwise no worries!! Thank you again for supporting the game!