diff --git a/assets/hub-globe.js b/assets/hub-globe.js
index 59023a2..a8e9ae9 100644
--- a/assets/hub-globe.js
+++ b/assets/hub-globe.js
@@ -11,7 +11,7 @@
  * globe3d=8: hub SVG ellipse trace (breaks under rotation — deprecated).
  * globe3d=9: v4 sphere grid only (thin E–W + N–S) — proper rotation baseline.
  * globe3d=10: v4 visible-arc → screen ellipse (hub ry), disk-clipped.
- * globe3d=11: v10 grid + visible-hemisphere continent wrap (ortho hub + mercator flat).
+ * globe3d=11: v10 grid + mercator-flat land wrap (lon center 12°, inverse Mercator Y).
  */
 export const GLOBE_VIEW = { imgW: 1920, imgH: 1080, cx: 720, cy: 560, r: 322, rim: 330 };
 
@@ -20,6 +20,8 @@ const DRAG_ROTATION_PER_PX = 0.004;
 const OCEAN_FALLBACK = { r: 22, g: 38, b: 60 };
 const FRONT_Z = 0.04;
 const LIMB_Z = 0.002;
+/** hub-logo-continents ortho / flat map center (extract_red_polygons.py). */
+const MERCATOR_LON_CENTER = (12 * Math.PI) / 180;
 const RASTER_SCALE = 2;
 const AXIS_STEPS = 160;
 const SPHERE_AXIS_STEPS = 180;
@@ -877,19 +879,44 @@ function texLonLat(tex) {
   };
 }
 
+function wrapLon(lon) {
+  let l = lon;
+  while (l > Math.PI) {
+    l -= Math.PI * 2;
+  }
+  while (l < -Math.PI) {
+    l += Math.PI * 2;
+  }
+  return l;
+}
+
+/** Inverse Mercator row — matches extract_red_polygons.py mercator_y_to_lat. */
+function latToMercatorRow(lat, h) {
+  const clamped = Math.max(-1.52, Math.min(1.52, lat));
+  const t = 0.5 + Math.asinh(Math.tan(clamped)) / (2 * Math.PI);
+  return Math.max(0, Math.min(h - 1, (1 - t) * (h - 1)));
+}
+
 function sampleMercFlat(mercFlat, lon, lat) {
-  const u = ((lon + Math.PI) / (2 * Math.PI)) * (mercFlat.w - 1);
-  const v = (0.5 - lat / Math.PI) * (mercFlat.h - 1);
+  const u = ((wrapLon(lon) + Math.PI) / (2 * Math.PI)) * (mercFlat.w - 1);
+  const v = latToMercatorRow(lat, mercFlat.h);
   return sampleImageDataBilinear(mercFlat.data, mercFlat.w, mercFlat.h, u, v);
 }
 
+/** Sphere tex → mercator-flat plate (lon offset + inverse Mercator Y). */
+function sampleMercFlatFromTex(mercFlat, tex) {
+  const ll = texLonLat(tex);
+  const lon = wrapLon(ll.lon + MERCATOR_LON_CENTER);
+  return sampleMercFlat(mercFlat, lon, ll.lat);
+}
+
 function isLandPixel(r, g, b, a) {
   return a > 10 && r > 100 && g < 140 && b < 140;
 }
 
 /** hub-logo-continents-mercator-{globe,flat}.svg grey-blue fills (not red JPG extract). */
 function isHubContinentPixel(r, g, b, a) {
-  if (a < 12) {
+  if (a < 8) {
     return false;
   }
   if (r > 168 && g > 198 && b > 218) {
@@ -905,6 +932,10 @@ function isHubContinentPixel(r, g, b, a) {
   return b >= 100 && g >= 95 && r >= 68;
 }
 
+function hubContinentRgba(sample) {
+  return [sample[0], sample[1], sample[2], 255];
+}
+
 /** Light hub grid strokes baked into hub-logo-fragment-globe.svg (vector grid drawn separately). */
 function isGridPixel(r, g, b, a) {
   if (a < 12) {
@@ -969,19 +1000,14 @@ function sampleLandRgbaMercator(mercFlat, tex) {
   return null;
 }
 
-/** globe3d=11 — same visible hemisphere as v10 grid (z > LIMB_Z); ortho hub then mercator wrap. */
-function sampleLandVisibleHemisphere(continents, mercFlat, tex) {
+/** globe3d=11 — visible hemisphere (z > LIMB_Z); mercator-flat wrap (single source, no ortho ghost). */
+function sampleLandVisibleHemisphere(mercFlat, tex) {
   if (tex.z <= LIMB_Z) {
     return null;
   }
-  const ortho = sampleHub(continents, tex);
-  if (isHubContinentPixel(ortho[0], ortho[1], ortho[2], ortho[3])) {
-    return [ortho[0], ortho[1], ortho[2], Math.min(255, ortho[3])];
-  }
-  const ll = texLonLat(tex);
-  const flat = sampleMercFlat(mercFlat, ll.lon, ll.lat);
+  const flat = sampleMercFlatFromTex(mercFlat, tex);
   if (isHubContinentPixel(flat[0], flat[1], flat[2], flat[3])) {
-    return [flat[0], flat[1], flat[2], Math.min(255, flat[3])];
+    return hubContinentRgba(flat);
   }
   return null;
 }
@@ -1196,7 +1222,7 @@ export async function mountHubGlobe(stage, opts) {
         cy,
         r,
         fillDiskRegion(ctx, cx, cy, r, rotation, function (tex) {
-          const l = sampleLandVisibleHemisphere(continents, mercFlat, tex);
+          const l = sampleLandVisibleHemisphere(mercFlat, tex);
           return l || [0, 0, 0, 0];
         })
       );
diff --git a/index.php b/index.php
index 48befd2..37e30cc 100644
--- a/index.php
+++ b/index.php
@@ -187,7 +187,7 @@ function hub_h(string $s): string {
       var supportsLayout = !!(window.CSS && CSS.supports && CSS.supports('object-fit', 'cover'));
       var logoEnabled = !!(stage && supportsSvg && supportsLayout);
 
-      var logoBuild = '20260704globe14';
+      var logoBuild = '20260704globe15';
 
       function hubAsset(rel) {
         var link = document.querySelector('link[href*="hub.css"]');