Image block hover opaque

With top icons, you can use this to Custom CSS box

/* Homepage */
.fe-66b1055a505e23dcc59b04c0 .image-block:hover img {
    opacity: 0.2;
}

With next icons, use this CSS code

section[data-section-id="66b10773c533dbfc9fb1d38a"] .summary-item:hover img {
    opacity: 0.2;
}