CSS: Invalid display: grid ??

[BedfordWriter]

I'm trying to build my own grid based on a web tutorial. The starting point, directly from the tutorial, is shown below but Flare invariably throws an error:
CSS: C:\DocTest\Content\WebHome.htm: CSS: Invalid display: grid
Any idea why "grid" is an invalid display option in Flare? (The page is configured for local styles only so nothing from Flare should be interfering - MadCap:onlyLocalStylesheets="True")

Code: Select all

.hero {
  padding: 4rem 2rem;

  /* Grid styles */
  display: grid;
  align-items: center;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

[Psider]

While I don't use grid, I think it'll be fine in the output and you can ignore the error in Flare.

You might like to look at this thread where someone has posted a possible temporary workaround for the same error for flex. (And suggestions for bugging (sorry ) Madcap about it.)

viewtopic.php?t=27423