Fix hover color on landing page cards

It needs to be set to the same color as the button in the card,
otherwise the hover color looks out of place.

docs/_static/custom.css

@@ -18,6 +18,7 @@ table.swh-logos-table ul {
 }
 
 .landing-part {
+  --sd-color-card-border-hover: var(--sd-color-primary);
   padding-bottom: 50vh;
 background-image: url("data:image/svg+xml,%3Csvg width='78.27' height='77.395' version='1.1' viewBox='0 0 78.27 77.395' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='blur'%3E%3CfeGaussianBlur in='SourceGraphic' stdDeviation='1' /%3E%3C/filter%3E%3Cg transform='matrix(1.25 0 0 -1.25 -15.707 134.24)' fill-opacity='.10' filter='url(%23blur)'%3E%3Cpath d='m30.574 68.987 1.337-1.343 4.826 1.607-1.61-4.823 1.34-1.34 2.95 8.844z'/%3E%3Cpath d='m27.188 67.914 5.746-10.675 1.252 1.252-5.747 10.674z'/%3E%3Cpath d='m24.636 57.152 1.608 4.823-1.34 1.34-2.949-8.846 8.842 2.949-1.338 1.343z'/%3E%3Cpath d='m44.012 65.874 2.274-5.144h1.894l-4.167 8.935-4.17-8.038 1.895-0.154z'/%3E%3Cpath d='m38.214 58.771 12-3.485v1.77l-12 3.484z'/%3E%3Cpath d='m44.012 49.269-2.273 4.461h-1.895l4.169-8.252 4.167 8.379-1.896-0.018z'/%3E%3Cpath d='m57.288 69.377-8.843 2.95 2.945-8.844 1.342 1.338-1.607 4.825 4.823-1.609z'/%3E%3Cpath d='m61.884 67.095-10.674-5.748 1.251-1.25 10.675 5.746z'/%3E%3Cpath d='m61.616 62.367 1.609-4.822-4.822 1.607-1.34-1.34 8.843-2.948-2.948 8.842z'/%3E%3Cpath d='m58.214 81.089-8.219-4.168 8.396-4.17 0.033 1.896-4.653 2.274 4.443 2.273z'/%3E%3Cpath d='m61.606 70.73 3.486 12h-1.771l-3.484-12z'/%3E%3Cpath d='m67.214 72.752 7.967 4.169-8.522 4.168-0.095-1.896 4.873-2.272-4.223-2.274z'/%3E%3Cpath d='m56.894 84.299-1.339 1.342-4.824-1.608 1.608 4.823-1.34 1.341-2.948-8.844z'/%3E%3Cpath d='m60.28 85.371-5.746 10.675-1.253-1.253 5.748-10.673z'/%3E%3Cpath d='m62.832 96.134-1.608-4.823 1.341-1.339 2.947 8.843-8.842-2.949 1.339-1.341z'/%3E%3Cpath d='m45.73 91.364-2.274-4.365-2.274 4.731h-1.894l4.168-8.521 4.17 8.245z'/%3E%3Cpath d='m50.214 94.515-12 3.485v-1.77l12-3.485z'/%3E%3Cpath d='m43.456 103.6 2.274-4.873h1.895l-4.169 8.664-4.169-8.175 1.896-0.083z'/%3E%3Cpath d='m36.076 89.803-1.341-1.34 1.608-4.823-4.823 1.608-1.34-1.34 8.844-2.949z'/%3E%3Cpath d='m25.582 86.192 10.674 5.746-1.251 1.251-10.675-5.746z'/%3E%3Cpath d='m25.85 90.918-1.608 4.823 4.824-1.608 1.339 1.341-8.844 2.948 2.949-8.844z'/%3E%3Cpath d='m29.214 72.196 8.338 4.169-8.338 4.169v-1.896l4.547-2.273-4.547-2.274z'/%3E%3Cpath d='m24.146 70.73 3.485 11h-1.769l-3.485-11z'/%3E%3Cpath d='m12.565 76.365 8.3384 4.169v-1.896l-4.5472-2.273 4.5472-2.274v-1.895z'/%3E%3C/g%3E%3C/svg%3E");  background-repeat: no-repeat;
   background-position: center bottom 17.5vh;