fix: graph layout, node visibility and FA2 settings

- Switch to CSS Grid layout for reliable content area height
- Use inferSettings() for ForceAtlas2 auto-tuning based on graph structure
- Enable linLogMode and adjustSizes for better node clustering
- Fit camera after layout settles with animatedReset
- Increase node sizes for better visibility (MIN 8, MAX 40)
- Center controls at bottom, fix overlay positions

src/pages/ReferralNetwork/ReferralNetwork.tsx

@@ -31,10 +31,10 @@ export function ReferralNetwork() {
   return (
     <div
       id="referral-network-container"
-      className="fixed inset-x-0 bottom-0 top-16 z-40 flex flex-col bg-[#0a0a0f] sm:top-14"
+      className="fixed inset-x-0 bottom-0 top-16 z-40 grid grid-rows-[auto_1fr] bg-[#0a0a0f] sm:top-14"
     >
       {/* Top bar */}
-      <div className="relative z-20 shrink-0 border-b border-dark-700/50 bg-dark-900/90 backdrop-blur-md">
+      <div className="z-20 border-b border-dark-700/50 bg-dark-900/90 backdrop-blur-md">
         <div className="flex items-center gap-2 px-3 py-2 sm:gap-3 sm:px-4 sm:py-3">
           <AdminBackButton />
           <h1 className="shrink-0 text-sm font-bold text-dark-100 sm:text-base">
@@ -45,11 +45,11 @@ export function ReferralNetwork() {
         </div>
       </div>
 
-      {/* Main content area */}
+      {/* Main content area — grid row takes all remaining space */}
-      <div className="relative min-h-0 flex-1">
+      <div className="relative overflow-hidden">
         {/* Loading state */}
         {isLoading && (
-          <div className="absolute inset-0 flex items-center justify-center">
+          <div className="absolute inset-0 z-10 flex items-center justify-center">
             <div className="text-center">
               <div className="mx-auto mb-3 h-8 w-8 animate-spin rounded-full border-2 border-dark-600 border-t-accent-400" />
               <p className="text-sm text-dark-400">{t('admin.referralNetwork.loading')}</p>
@@ -59,35 +59,35 @@ export function ReferralNetwork() {
 
         {/* Error state */}
         {isError && (
-          <div className="absolute inset-0 flex items-center justify-center">
+          <div className="absolute inset-0 z-10 flex items-center justify-center">
             <p className="text-sm text-error-400">{t('admin.referralNetwork.error')}</p>
           </div>
         )}
 
         {/* Empty state */}
         {networkData && networkData.users.length === 0 && networkData.campaigns.length === 0 && (
-          <div className="absolute inset-0 flex items-center justify-center">
+          <div className="absolute inset-0 z-10 flex items-center justify-center">
             <p className="text-sm text-dark-500">{t('admin.referralNetwork.empty')}</p>
           </div>
         )}
 
-        {/* Graph */}
+        {/* Graph — fills entire content area */}
         {networkData && (networkData.users.length > 0 || networkData.campaigns.length > 0) && (
           <>
-            <NetworkGraph data={networkData} className="absolute inset-0" />
+            <NetworkGraph data={networkData} className="absolute inset-0 h-full w-full" />
 
             {/* Bottom-left: stats overlay */}
-            <div className="absolute bottom-4 left-4 z-10">
+            <div className="absolute bottom-3 left-3 z-10 sm:bottom-4 sm:left-4">
               <NetworkStats data={networkData} />
             </div>
 
             {/* Bottom-right: legend (hidden on mobile to avoid overlap) */}
-            <div className="absolute bottom-4 right-4 z-10 hidden sm:block">
+            <div className="absolute bottom-3 right-3 z-10 hidden sm:bottom-4 sm:right-4 sm:block">
               <NetworkLegend />
             </div>
 
-            {/* Bottom-right on mobile, bottom-center on desktop: controls */}
+            {/* Bottom-center: controls */}
-            <div className="absolute bottom-4 right-4 z-10 sm:left-1/2 sm:right-auto sm:-translate-x-1/2">
+            <div className="absolute bottom-3 left-1/2 z-10 -translate-x-1/2 sm:bottom-4">
               <NetworkControls />
             </div>
           </>

src/pages/ReferralNetwork/components/NetworkGraph.tsx

@@ -2,6 +2,7 @@ import { useEffect, useRef, useCallback } from 'react';
 import Graph from 'graphology';
 import Sigma from 'sigma';
 import FA2LayoutSupervisor from 'graphology-layout-forceatlas2/worker';
+import { inferSettings } from 'graphology-layout-forceatlas2';
 import { useReferralNetworkStore } from '@/store/referralNetwork';
 import type { NetworkGraphData, NetworkFilters } from '@/types/referralNetwork';
 import { getUserNodeColor, getUserNodeSize, getCampaignColor } from '../utils';
@@ -246,24 +247,31 @@ export function NetworkGraph({ data, className }: NetworkGraphProps) {
 
       // Start ForceAtlas2 in a web worker (non-blocking)
       if (graph.order > 0) {
+        const inferred = inferSettings(graph);
         const supervisor = new FA2LayoutSupervisor(graph, {
           settings: {
-            gravity: 0.5,
+            ...inferred,
-            scalingRatio: 10,
+            linLogMode: true,
-            barnesHutOptimize: true,
+            adjustSizes: true,
-            slowDown: 2,
+            barnesHutOptimize: graph.order > 100,
+            slowDown: 5,
           },
         });
         fa2Ref.current = supervisor;
         supervisor.start();
 
-        // Kill after a fixed duration to free the web worker thread
+        // Kill after a fixed duration, then fit camera to all nodes
         fa2TimerRef.current = setTimeout(() => {
           if (fa2Ref.current === supervisor) {
             supervisor.kill();
             fa2Ref.current = null;
           }
           fa2TimerRef.current = null;
+
+          // Fit camera to show all nodes after layout settles
+          if (sigmaRef.current) {
+            sigmaRef.current.getCamera().animatedReset({ duration: 400 });
+          }
         }, FA2_DURATION_MS);
       }
 

src/pages/ReferralNetwork/utils.ts

@@ -46,8 +46,8 @@ export function getUserNodeColor(
  * Size is proportional to direct_referrals, clamped between min and max.
  */
 export function getUserNodeSize(directReferrals: number): number {
-  const MIN_SIZE = 4;
+  const MIN_SIZE = 8;
-  const MAX_SIZE = 30;
+  const MAX_SIZE = 40;
   if (directReferrals === 0) return MIN_SIZE;
-  return Math.min(MAX_SIZE, MIN_SIZE + Math.sqrt(directReferrals) * 4);
+  return Math.min(MAX_SIZE, MIN_SIZE + Math.sqrt(directReferrals) * 5);
 }