Help target just 1 attribute

Hi, i’m tryng to display a single attribute, i’ve seen this code in the documentation :
/* target just 1 attribute */
.custom-attributes li.YOUR-ATTRIBUTE-SLUG { }

i’ve try :

.custom-attributes li.CONTENANCE { }
.custom-attributes li.contenance { }
.custom-attributes li.PA_CONTENANCE{ }
.custom-attributes li.pa_contenance{ }
.custom-attributes li.PA_CONTENANCE-SLUG { }
.custom-attributes li.pa-contenance-SLUG { }
.custom-attributes li.PA-CONTENANCE-SLUG { }
.custom-attributes li.pa-contenance { }
.custom-attributes li.pa-CONTENANCE { }

Here is the attribute in the back office : https://i.imgur.com/A0WbuvC.png

No idea what i’m doing wrong, but other css like italic works but i cant get the “target just 1 attribute”

If anyone have a clue of what i’m doing wrong…

Thx