fixed html header issue and forced 16:9 thumbnail aspect

src/css/style.css

@@ -472,3 +472,22 @@ footer a:hover {
 
   pointer-events: none;
 }
+
+/* Create a container that preserves a 16:9 aspect ratio via padding-top. */
+/* Force 16:9 ratio using padding-top technique */
+.ratio-16-9 {
+  position: relative;
+  width: 100%;
+  padding-top: 56.25%; /* 16:9 => 9/16 = 0.5625 => 56.25% */
+  background-color: #1e293b; /* fallback background if image doesn't load */
+}
+
+.ratio-16-9 > img {
+  position: absolute;
+  top: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
+  object-fit: cover;
+}
+