These are the errors:
1. : filter in code:
.main-navigation ul li:after {
content: ”;
position: absolute;
height: 0;
width: 100%;
bottom: 0;
left: 0;
pointer-events: none;
filter: hue-rotation(90deg);
-webkit-filter: hue-rotation(90deg);
-webkit-transition: height 0.35s ease;
transition: height 0.35s ease;
}
2.: grid template
3.: grid rows
@media (min-width: 900px) {
.wpsp-grid .wp-show-posts {
grid-template-columns: repeat(8, 1fr);
grid-template-rows: 1fr auto;
}