I received an email from HR stating that my final interview was "successful." However, there was no offer letter, salary details, or start date mentioned—just the word "successful." I'm feeling a mix of excitement and caution. Should I allow myself to be happy about this? Part of me wants to inform my current manager that I might be leaving, but I've been burned in the past and know that "successful" doesn't guarantee anything until I have something in writing. I'm unsure about what my next steps should be.