How can i write a new css file for Discuz!ML?

vot

yes, i edit its name! i did this process for collection, cuz of style of it, is not correct in Ar view, you can check here!
i asked my doing is right?

Yes.

(i point in pic that css file that i get)
style_1_forum_collection.css

So you have to find a source css file containing the next key inside: "forum::collection".
As you can see, it is the "/template/default/common/module.css"!

So you must edit the module_rtl.css file, the section with "forum::collection".

vot

Compare the module.css and module_rtl.css,
insert all new lines from module.css to module_rtl.css,
and then MIRROR new added lines in RTL file.

vot

i will upload new file

NO!!!
Upload just a PATCH!

(You said you are ready to learn new technologies ;-) )

vot

Ask help from Khalid if required...