diff --git a/layouts/shortcodes/world-map.html b/layouts/shortcodes/world-map.html
index ef3dbf3..cfabdcc 100644
--- a/layouts/shortcodes/world-map.html
+++ b/layouts/shortcodes/world-map.html
@@ -6,7 +6,8 @@
 .ifk-map-wrap { max-width: 100%; margin: 2rem 0; }
 .ifk-map-wrap h3 { text-align: center; margin-bottom: 0.5rem; font-size: 1.25rem; }
 .ifk-map-subtitle { text-align: center; color: #666; font-size: 0.85rem; margin-bottom: 1rem; }
-#ifk-world-map { width: 100%; height: 420px; border-radius: 8px; background: #c8d3df; }
+#ifk-world-map { width: 100%; height: 420px; border-radius: 8px; background: #fff; -webkit-backface-visibility: hidden; backface-visibility: hidden; }
+#ifk-world-map .leaflet-map-pane, #ifk-world-map .leaflet-overlay-pane { -webkit-backface-visibility: hidden; backface-visibility: hidden; }
 .ifk-map-legend {
   display: flex; flex-wrap: wrap; gap: 1rem; justify-content: center;
   margin-top: 1rem; font-size: 0.8rem;
@@ -110,6 +111,11 @@
     if (!L.Browser.ie && !L.Browser.opera && !L.Browser.edge) layer.bringToFront();
   }
 
+  // Ocean as SVG rectangle — same compositing layer as countries, prevents GPU seams
+  L.rectangle([[-90, -180], [90, 180]], {
+    fillColor: '#c8d3df', fillOpacity: 1, stroke: false, interactive: false
+  }).addTo(map);
+
   fetch('{{ "data/countries-50m.json" | relURL }}')
     .then(function(r) { return r.json(); })
     .then(function(topo) {