style(related): two-up on desktop, one-up on phones

Six photo cards in 2 columns (3 rows) at desktop widths; phones collapse to a
single full-width column and still show only the first four. Drops the 900px
two-column step (now the base) and the cramped-card type overrides that only
existed for the 2-up phone grid.

src/styles/global.css

@@ -426,7 +426,7 @@ pre code {
 .related { margin-top: 3rem; padding-top: 1.5rem; border-top: 1px solid var(--border); }
 .related-grid {
   display: grid;
-  grid-template-columns: repeat(3, 1fr);
+  grid-template-columns: repeat(2, 1fr);
   gap: 1rem;
   margin-top: 1rem;
 }
@@ -521,12 +521,6 @@ pre code {
   margin: 1rem 0 2.5rem;
 }
 
-@media (max-width: 900px) {
-  /* Three photo cards per row stops working below ~900px — the OG art is
-     1200x630 with baked-in type, so it needs width to stay readable. */
-  .related-grid { grid-template-columns: repeat(2, 1fr); }
-}
-
 @media (max-width: 680px) {
   .featured-bento-grid {
     grid-template-columns: 1fr;
@@ -915,15 +909,9 @@ a.category-card:hover { border-color: var(--brand); }
   .nav { padding: 0.8rem 1.25rem; gap: 0.85rem; }
   h1 { font-size: 1.7rem; }
   h2 { font-size: 1.25rem; }
-  /* Related grid: four photo cards on phones (the last two are hidden), and
-     keep the type small enough that a 160px-wide card still reads. */
-  .related-grid { grid-template-columns: repeat(2, 1fr); gap: 0.75rem; }
+  /* Related grid: one full-width card per row on phones, first four only. */
+  .related-grid { grid-template-columns: 1fr; gap: 0.85rem; }
   .related-extra { display: none; }
-  .related-card h3 { font-size: 0.82rem; }
-  .related-card time { font-size: 0.7rem; }
-  .related-read { display: none; }   /* date alone fits a 160px card */
-  .related-body { padding: 0.6rem 0.65rem; }
-  .related-badge { font-size: 0.6rem; margin-bottom: 0.35rem; }
   .featured-bento-grid { grid-template-columns: 1fr; }
   .proof-grid { grid-template-columns: repeat(2, 1fr); }
   .stack-grid, .contact-split { grid-template-columns: 1fr; }