This is the 449th most frequent Chinese word.
良好
Good; favorable; well.
Here, '良好' describes the 'mindset' as healthy and positive, emphasizing the desirability of this attribute.
保持良好的心态非常重要。
Maintaining a positive mindset is very important.
In this sentence, '良好' is used as an adjective to describe positive and commendable study habits, providing a sense of excellence or well quality.
她有着良好的学习习惯。
She has good study habits.
In this instance, '良好' modifies '环境' (environment) to denote that the environment is favorable and conducive for productivity.