style: optimize github card for mobile, adjust spacing between consecutive images

src/styles/heti.css

@@ -92,6 +92,12 @@
 .heti :where(figure) {
   --at-apply: 'mx-auto mt-3 mb-6';
 }
+.heti :where(figure:has(+ figure)) {
+  --at-apply: 'mb-4';
+}
+.heti :where(figure:has(+ p > img:first-child)) {
+  --at-apply: 'mb-4';
+}
 .heti :where(figcaption) {
   --at-apply: 'text-center text-sm mt-3 text-secondary/80';
 }