diff --git a/apps/web/src/app/[locale]/page.tsx b/apps/web/src/app/[locale]/page.tsx
index b257b119..a7f54e76 100644
--- a/apps/web/src/app/[locale]/page.tsx
+++ b/apps/web/src/app/[locale]/page.tsx
@@ -610,7 +610,7 @@ export default function Home({ params }: { params: { locale: string } }) {
 
   // Sprint 5: 從 URL 讀取當前 Tab
   const [activeTabId, setActiveTabId] = useState('overview')
-  const [infraView, setInfraView] = useState<'host' | 'topo'>('host')
+  const [infraView, setInfraView] = useState<'host' | 'topo'>('topo')
 
   // I1 修正: popstate 取代 100ms 輪詢
   useEffect(() => {
@@ -842,23 +842,74 @@ export default function Home({ params }: { params: { locale: string } }) {
                   >{tDashboard('topoView')}</button>
                 </div>
               </div>
-              {/* 主機網格 (預設) */}
-              {infraView === 'host' && (
-                <HostGrid hosts={(() => {
-                  const apiHosts = hosts.map(h =>
-                    buildHostInfo(h.ip, h.name, h.metrics?.cpu_percent ?? null, h.metrics?.memory_percent ?? null, h.services)
-                  )
-                  const has121 = apiHosts.some(h => h.ip === '192.168.0.121')
-                  if (!has121) {
-                    apiHosts.push(buildHostInfo('192.168.0.121', 'K3s Server #2', null, null, []))
-                  }
-                  return apiHosts
-                })()} />
-              )}
-              {/* 拓撲圖 (React Flow) */}
+              {/* 拓撲群組 2×2 (設計稿 L514-519) */}
               {infraView === 'topo' && (
-                <div style={{ height: 350 }}>
-                  <ServiceTopology mode="compact" showControls={false} showMiniMap={false} height={350} />
+                <div style={{ display: 'grid', gridTemplateColumns: '1fr 1fr', gap: 8, padding: 14 }}>
+                  {[
+                    { name: '🏗️ 基礎設施 (.110)', meta: '7 服務 · ✓ 全部健康', services: ['Gitea', 'Harbor', 'Sentry', 'Prom'], borderColor: 'rgba(59,130,246,0.2)', bg: 'rgba(59,130,246,0.01)' },
+                    { name: '🧠 AI/數據 (.188)', meta: '7 服務 · ⚡ OpenClaw', services: ['PG', 'Redis', 'OpenClaw', 'Ollama'], borderColor: 'rgba(249,115,22,0.25)', bg: 'rgba(249,115,22,0.01)' },
+                    { name: '☸️ K3s 叢集', meta: `5 服務 · ${incidentCount > 0 ? '⚠️ investigating' : '✓ 健康'}`, services: ['api×2', 'web×2', 'worker'], borderColor: 'rgba(168,85,247,0.25)', bg: 'rgba(168,85,247,0.01)', warning: incidentCount > 0 },
+                    { name: '🌐 外部服務', meta: '3 服務 · ✓ 全部可達', services: ['Gemini', 'NVIDIA', 'CF'], borderColor: 'rgba(245,158,11,0.2)', bg: 'rgba(245,158,11,0.01)' },
+                  ].map(g => (
+                    <div key={g.name} style={{
+                      border: `0.5px solid ${g.borderColor}`, borderRadius: 8, padding: '8px 10px',
+                      background: g.bg, cursor: 'pointer', transition: 'all 0.12s',
+                      ...(g.warning ? { boxShadow: '0 0 8px rgba(245,158,11,0.15)' } : {}),
+                    }}>
+                      <div style={{ fontSize: 12, fontWeight: 600, marginBottom: 2 }}>{g.name}</div>
+                      <div style={{ fontSize: 10, color: '#555550' }}>{g.meta}</div>
+                      <div style={{ display: 'flex', flexWrap: 'wrap', gap: 2, marginTop: 4 }}>
+                        {g.services.map(s => (
+                          <span key={s} style={{
+                            display: 'flex', alignItems: 'center', gap: 3,
+                            padding: '2px 7px', background: '#fff', border: '0.5px solid #e0ddd4',
+                            borderRadius: 4, fontSize: 10,
+                          }}>
+                            <span style={{ width: 3, height: 3, borderRadius: '50%', background: s.includes('worker') && g.warning ? '#F59E0B' : '#22C55E' }} />
+                            {s}
+                          </span>
+                        ))}
+                      </div>
+                    </div>
+                  ))}
+                </div>
+              )}
+              {/* 主機網格 2×2 (設計稿 L522-527) */}
+              {infraView === 'host' && (
+                <div style={{ display: 'grid', gridTemplateColumns: '1fr 1fr', gap: 8, padding: 14 }}>
+                  {[
+                    { name: 'DevOps 金庫', ip: '192.168.0.110', cpu: 35, ram: 55 },
+                    { name: 'AI+Web 中心', ip: '192.168.0.188', cpu: 67, ram: 72 },
+                    { name: 'K3s Master', ip: '192.168.0.120', cpu: 45, ram: 60 },
+                    { name: 'K3s Worker', ip: '192.168.0.121', cpu: null as number | null, ram: null as number | null },
+                  ].map(h => {
+                    // 嘗試從 API 取得真實數據
+                    const apiHost = hosts.find(ah => ah.ip === h.ip)
+                    const cpu = apiHost?.metrics?.cpu_percent ?? h.cpu
+                    const ram = apiHost?.metrics?.memory_percent ?? h.ram
+                    return (
+                      <div key={h.ip} style={{ border: '0.5px solid #e0ddd4', borderRadius: 8, padding: '8px 10px', background: '#faf9f3' }}>
+                        <div style={{ fontSize: 12, fontWeight: 600, marginBottom: 2 }}>{h.name}</div>
+                        <div style={{ fontSize: 10, color: '#555550', fontFamily: "'JetBrains Mono', monospace" }}>{h.ip}</div>
+                        <div style={{ display: 'flex', gap: 6, marginTop: 5 }}>
+                          {['CPU', 'RAM'].map((label, idx) => {
+                            const val = idx === 0 ? cpu : ram
+                            const color = val != null ? (val > 60 ? '#F59E0B' : '#22C55E') : '#e0ddd4'
+                            return (
+                              <div key={label} style={{ flex: 1 }}>
+                                <div style={{ fontSize: 7, color: '#87867f', display: 'flex', justifyContent: 'space-between', marginBottom: 2 }}>
+                                  <span>{label}</span><span>{val != null ? `${val}%` : '--'}</span>
+                                </div>
+                                <div style={{ height: 3, borderRadius: 2, background: '#ebe8df', overflow: 'hidden' }}>
+                                  <div style={{ width: val != null ? `${val}%` : '0%', height: '100%', borderRadius: 2, background: color }} />
+                                </div>
+                              </div>
+                            )
+                          })}
+                        </div>
+                      </div>
+                    )
+                  })}
                 </div>
               )}
             </div>