haha.这个fighter's问题我知道答案。几年前我感到迷惑过，后来就淡定了。

这个问题我知道答案。几年前我感到迷惑过，后来就淡定了。

In American English , A "t" in the middle of a word like LATTER, PARTY, and LITTLE can be pronounced as a soft " d ", the d sound like the d in LADDER, HARDY, and MIDDLE.

this sound usually occurs between vowels(especially before an unstressed vowel ), between r and a vowel, or before a syllabic /l/. THe word "FIGHTING" belongs to the 1st case with yellow highlight.

I'm happy that not all Americans pronounce this way, so the rule is not consistent.
I'm lazy and dumb. In all cases, I usually pronounce t as t sound, no change. but sometimes I do change some t to d sound without being aware of the changes:)