diff --git a/make_post_sell/static/css/common.css b/make_post_sell/static/css/common.css
index 2e73947..da4474d 100644
--- a/make_post_sell/static/css/common.css
+++ b/make_post_sell/static/css/common.css
@@ -1355,6 +1355,15 @@ div.serp-item:hover {
 }
 
 img.serp-thumbnail {
+    /* width: auto + max-width: 100% per CLAUDE.md CSS Media Sizing:
+       lets the image shrink to fit its grid cell without forcing the
+       cell to expand to the image's natural width (which on
+       printableprompts is 1080px+ and was collapsing the auto-fit
+       grid to a single full-viewport column). */
+    width: auto;
+    max-width: 100%;
+    height: auto;
+    display: block;
     border-radius: var(--radius-sm, 4px);
 }