Is it permissible for a woman to work in a mixed-gender environment while adhering to Islamic manners, lowering her gaze, and limiting interactions to professional boundaries?

Not all mixing (of genders) at work is forbidden; rather, some of it is permissible, and some is prohibited. A woman's work is permissible if the work itself is lawful, and the woman adheres to the শরعي (Shari'i) guidelines, such as wearing the hijab, maintaining modesty, avoiding privacy with a non-mahram man (khalwa), refraining from gazes, and not speaking in a soft or alluring manner. Therefore, if your work in the company is permissible and you adhere to the শরعي (Shari'i) guidelines in dealing with men, then there is no blame upon you for it.