Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.3.7)
// Compass (v1.0.0.alpha.18)
// ----

@mixin smallscreen() {

	// landscape, width < 599, ensuring device is landscape and not portrait with keyboard open
	@media all and (orientation: landscape) and (max-width: 599px) and (min-device-aspect-ratio: 1/1),

		// landscape, height < 399, ensuring device is landscape, but not when extra widescreen because keyboard is open
		all and (orientation: landscape) and (max-height: 399px) and (min-device-aspect-ratio: 1/1) and (max-aspect-ratio: 3/1),

		// portrait, width < 499
		all and (orientation: portrait) and (max-width: 499px),

		// portrait, height < 599
		all and (orientation: portrait) and (max-height: 599px) {

		@content;
	}
}

@mixin portrait() {
	@media all and (orientation: portrait) {
		@content;
	}
}

.test {
  @include smallscreen {
    @include portrait {
      color: blue;
    }
  }
}

SassMeister-output.css

@media all and (orientation: landscape) and (max-width: 599px) and (min-device-aspect-ratio: 1 / 1) and (orientation: portrait), all and (orientation: landscape) and (max-height: 399px) and (min-device-aspect-ratio: 1 / 1) and (max-aspect-ratio: 3 / 1) and (orientation: portrait), all and (orientation: portrait) and (max-width: 499px) and (orientation: portrait), all and (orientation: portrait) and (max-height: 599px) and (orientation: portrait) {
  .test {
    color: blue;
  }
}