<div class="flag progress" role="img" aria-label="Progress Pride Flag. The traditional gay pride flag with 6 bars: red, orange, yellow, green, blue, and indigo. On the left side, it has triangles of color: white, pink, light blue, brown, and black."></div>

.flag {
  width: 80vmin;
  aspect-ratio: 70 / 45;
}

.flag.progress {
  background:
    conic-gradient(at 14% 50%, #0000 221.25deg, white 222deg 318deg, #0000 318.25deg),
    conic-gradient(at 23% 50%, #0000 221.25deg, #ffa6b9 222deg 318deg, #0000 318.25deg),
    conic-gradient(at 32% 50%, #0000 221.25deg, #00d2ff 222deg 318deg, #0000 318.25deg),
    conic-gradient(at 41% 50%, #0000 221.25deg, #753000 222deg 318deg, #0000 318.25deg),
    conic-gradient(at 50% 50%, #0000 221.25deg, black 222deg 318deg, #0000 318.25deg),
    linear-gradient(red 0 16.66%, orange 0 33.33%, yellow 0 50%, green 0 66.66%, blue 0 83.33%, indigo 0);
}