紋絲不動

纹丝不动
wénsībùdòng
to not move a single jot (idiom)

CEDICT

to not move a single bit

Wiktionary

絲毫不移動。

重編國語辭典

Entry Composition

1 紋絲 wénsī
  1. tiny bit
  2. a jot
  3. whisker
2 不動 bùdòng motionless