diff --git a/public/js/app.js b/public/js/app.js
index 53374e7..1980b38 100644
--- a/public/js/app.js
+++ b/public/js/app.js
@@ -795,21 +795,32 @@
                 const isAsia = (n) => n.includes('china') || n.includes('hong kong') || n.includes('singapore') || n.includes('korea') || n.includes('seoul') || n.includes('japan') || n.includes('tokyo') || n.includes('shanghai') || n.includes('beijing');
                 const isEurope = (n) => n.includes('germany') || n.includes('uk') || n.includes('france') || n.includes('london') || n.includes('frankfurt') || n.includes('paris') || n.includes('united kingdom');
 
+                // Specific ports for Trans-Pacific routing separation
+                const n = (route.source + ' ' + route.dest).toLowerCase();
+                const involvesSeattle = n.includes('seattle');
+                const involvesLA = n.includes('los angeles') || n.includes('san francisco') || n.includes('la');
+
                 // Determine base curveness to always bend North (Upward) for major East-West routes
                 // In this map: dx < 0 (Westward) -> negative curveness bends North
                 //              dx > 0 (Eastward) -> positive curveness bends North
                 let baseCurve = 0.2;
                 if (dx < 0) baseCurve = -0.2;
 
-                // Special case: Trans-Pacific (US <-> Japan/Asia) - usually deeper curve
+                // Special case: Trans-Pacific (US <-> Japan/Asia)
                 if ((isUS(src) && isAsia(dst)) || (isAsia(src) && isUS(dst))) {
-                    baseCurve = (dx < 0 ? -0.35 : 0.35);
+                    if (involvesSeattle) {
+                        baseCurve = (dx < 0 ? -0.45 : 0.45); // High North arc
+                    } else if (involvesLA) {
+                        baseCurve = (dx < 0 ? 0.35 : -0.35);  // South arc (positive for Westward = South)
+                    } else {
+                        baseCurve = (dx < 0 ? -0.3 : 0.3);    // Default slight North arc
+                    }
                 } 
-                // Trans-Atlantic (US <-> Europe) - use coordinates to detect
+                // Trans-Atlantic (US <-> Europe)
                 else if ((isUS(src) && isEurope(dst)) || (isEurope(src) && isUS(dst))) {
                     baseCurve = (dx < 0 ? -0.25 : 0.25);
                 }
-                // Intra-Asia or shorter routes - flatter curve
+                // Intra-Asia or shorter routes
                 else if (Math.abs(dx) < 50) {
                     baseCurve = (dx < 0 ? -0.15 : 0.15);
                 }