message: art: bug couleur ie11"
diff: background-image: linear-gradient(
  50deg,
  rgba(39, 69, 195, 0.87) 5%,
  - var(--colour) 50%,
  + rgb(41, 117, 209) 50%,
  rgba(41, 117, 209, 0.9) 55%
  );
  background-image: linear-gradient(
  