Despite the early setbacks, the team's positive mindset kept them ______________ throughout the project.

• In the pink (idiom): 
English Meaning: in extremely good health and spirits.
Bangla Meaning: পূর্ণ স্বাস্থ্যবান / খুব ভালো অবস্থা। 

Example Sentence: After the excellent result, I am in the pink now.
Bangla Meaning: অসাধারণ একটা ফলাফল পেয়ে আমি এখন খুব ভালো আছি।

এছাড়াও:  
In the dark - In a state of ignorance.

তাই, Complete Sentence - Despite the early setbacks, the team's positive mindset kept them in the pink throughout the project.