A: width: calc((100% - SOME_INTEGER_NUMBERpx) / 2)
B: width: calc((100%) / 2)
Original style rule of the element is A. When inspecting element with DEV tools (Opera) A style is not marked as invalid but it does not work either.
When changing calc expression to look like B (via DEV tools) element looks as expected.
Update 1:
As you can see the bowser likes the expression: it is parsed and is not being overriden
Update 2:
Must be an issue of Opera 60.0.3255.151 since other browsers apply CSS rule as expected. Will try another version of Opera and will report shortly. Thx @Ry
Update 3:
Same issue when browsing with Opera 58.0.3135.132. Sadly a hack (calc(100% / 2 - 55px / 2)
) suggested by someone whose comment/answer is no longer visible does not work either. Issue must be web-app connected