Neither of the following gradients are loaded in Safari 13.0.5:
background-image: radial-gradient(var(--sdc-color-primary-dark), var(--sdc-color-primary-light), transparent);
background: radial-gradient(var(--sdc-color-primary-dark), var(--sdc-color-primary-light), transparent);
background-color: radial-gradient(var(--sdc-color-primary-dark), var(--sdc-color-primary-light), transparent);
It's the fact that I am using variables, but I looked on the internet and I found that variables should be supported from an earlier version. Any ideeas?