fix: desaturate base map (white land, light gray sea)

Makes choropleth colors pop against neutral background.
Hides landcover/landuse/park fills.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

layouts/shortcodes/world-map.html

@@ -65,6 +65,20 @@ function ifkInitMap() {
   window._ifkMap.addControl(new maplibregl.NavigationControl({ showCompass: false }), 'top-right');
 
   window._ifkMap.on('load', function() {
+    // Desaturate base map: white land, light gray sea
+    var style = window._ifkMap.getStyle();
+    style.layers.forEach(function(l) {
+      if (l.id === 'background') {
+        window._ifkMap.setPaintProperty(l.id, 'background-color', '#e8e8e8');
+      }
+      if (l.type === 'fill' && (l.id.indexOf('water') >= 0 || l.id.indexOf('ocean') >= 0)) {
+        window._ifkMap.setPaintProperty(l.id, 'fill-color', '#f0f0f0');
+      }
+      if (l.type === 'fill' && (l.id.indexOf('landcover') >= 0 || l.id.indexOf('landuse') >= 0 || l.id.indexOf('park') >= 0)) {
+        window._ifkMap.setPaintProperty(l.id, 'fill-opacity', 0);
+      }
+    });
+
     fetch('{{ "data/countries-110m.json" | relURL }}')
       .then(function(r) { return r.json(); })
       .then(function(topo) {