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  • Thomas Handy thinks this is interesting:

I hope you’re not tired of all this good news because as it happens, the max-width: 100% rule can also apply to most fixed-width elements, like video and other rich media. In fact, we can beef up our selector to cover other media-ready elements, like so:

img,
embed,
object,
video {
  max-width: 100%;
}

From

Cover of Responsive Web Design

Note

using "max-width" for multiple elements