feat: 机器离线统计/日志、连通性重试检测与暗黑模式支持

后端更新：
- 在 machines 表新增 offline_count、total_offline_seconds、last_offline_at、last_offline_reason 字段，用于记录机器离线统计信息。
- 新增 offline_logs 表，记录每次离线的开始时间、结束时间、持续时长及离线原因。
- 重写 ping 服务为状态机模式：
  – 单台机器依次使用 system ping / ICMP / TCP(SSH端口) 三种方式检测连通性；
  – 任意一次成功即视为在线；
  – 若一次失败，则会连续重试 3 次（间隔 2 秒），3 次均失败才判定为离线，避免网络抖动导致误判。
  – 仅在状态发生 online→offline 或 offline→online 变化时更新 offline_logs 与累计时长。
  – 机器按顺序逐个检测，每台间隔 30 秒。
- 新增 API：GET /admin/machines/:id/offline-logs，用于查询最近 50 条离线记录。
- CleanupLogs 增加对 offline_logs 的过期清理。

前端更新：
- 机器详情页（MachineDetail.vue）新增离线统计卡片，展示离线次数、累计离线时长、上次离线原因及最近 5 条离线记录。
- 全局支持暗黑模式：
  – App.vue 引入 light/dark CSS 变量，并加载 Element Plus 深色主题（dark/css-vars.css）。
  – MainLayout.vue 侧边栏新增主题切换按钮，支持深浅色切换并持久化到 localStorage。
  – Topology.vue 监听主题变化，动态重绘 G6 节点/边的颜色、背景与阴影。
  – MachineList.vue / MachineDetail.vue 全面适配深色变量（卡片、表格、标签、进度条等）。
- 机器列表卡片 UI 调整：改为顶部 OS 色点 + 在线/离线状态胶囊标签，离线卡片降低透明度并去色。

构建与部署：
- 重新构建前端并打包静态资源。
- 交叉编译 Linux amd64 二进制并更新 deploy/lan-manager-debian12.tar.gz 部署包。

server/db/db.go

@@ -93,6 +93,20 @@ func migrate() error {
 		`CREATE INDEX IF NOT EXISTS idx_rel_src ON relationships(source_machine_id)`,
 		`CREATE INDEX IF NOT EXISTS idx_rel_tgt ON relationships(target_machine_id)`,
 		`CREATE INDEX IF NOT EXISTS idx_logs_created ON operation_logs(created_at)`,
+			`ALTER TABLE machines ADD COLUMN offline_count INTEGER DEFAULT 0`,
+			`ALTER TABLE machines ADD COLUMN total_offline_seconds INTEGER DEFAULT 0`,
+			`ALTER TABLE machines ADD COLUMN last_offline_at DATETIME`,
+			`ALTER TABLE machines ADD COLUMN last_offline_reason TEXT`,
+			`CREATE TABLE IF NOT EXISTS offline_logs (
+				id INTEGER PRIMARY KEY AUTOINCREMENT,
+				machine_id INTEGER NOT NULL REFERENCES machines(id) ON DELETE CASCADE,
+				reason TEXT,
+				started_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+				ended_at DATETIME,
+				duration_seconds INTEGER
+			)`,
+			`CREATE INDEX IF NOT EXISTS idx_offline_logs_machine ON offline_logs(machine_id)`,
+			`CREATE INDEX IF NOT EXISTS idx_offline_logs_started ON offline_logs(started_at)`,
 	}
 	for _, s := range stmts {
 		if _, err := DB.Exec(s); err != nil {

server/handlers/machines.go

@@ -38,7 +38,7 @@ func (h *MachineHandler) List(c *gin.Context) {
 	osFilter := c.Query("os_type")
 	search := c.Query("search")
 
-	query := `SELECT id, hostname, ip, mac, os_type, os_version, notes, ssh_port, ssh_username, ssh_password, is_online, last_ping_at, cpu_info, memory_info, disk_info, uptime, listen_ports, ssh_synced_at, created_at, updated_at FROM machines WHERE 1=1`
+	query := `SELECT id, hostname, ip, mac, os_type, os_version, notes, ssh_port, ssh_username, ssh_password, is_online, last_ping_at, cpu_info, memory_info, disk_info, uptime, listen_ports, ssh_synced_at, offline_count, total_offline_seconds, last_offline_at, last_offline_reason, created_at, updated_at FROM machines WHERE 1=1`
 	args := []interface{}{}
 	if osFilter != "" {
 		query += ` AND os_type = ?`
@@ -66,12 +66,14 @@ func (h *MachineHandler) List(c *gin.Context) {
 	for rows.Next() {
 		var m models.Machine
 		var lp, ss *time.Time
-		err := rows.Scan(&m.ID, &m.Hostname, &m.IP, &m.MAC, &m.OsType, &m.OsVersion, &m.Notes, &m.SSHPort, &m.SSHUsername, &m.SSHPassword, &m.IsOnline, &lp, &m.CPUInfo, &m.MemoryInfo, &m.DiskInfo, &m.Uptime, &m.ListenPorts, &ss, &m.CreatedAt, &m.UpdatedAt)
+		var lo *time.Time
+		err := rows.Scan(&m.ID, &m.Hostname, &m.IP, &m.MAC, &m.OsType, &m.OsVersion, &m.Notes, &m.SSHPort, &m.SSHUsername, &m.SSHPassword, &m.IsOnline, &lp, &m.CPUInfo, &m.MemoryInfo, &m.DiskInfo, &m.Uptime, &m.ListenPorts, &ss, &m.OfflineCount, &m.TotalOfflineSeconds, &lo, &m.LastOfflineReason, &m.CreatedAt, &m.UpdatedAt)
 		if err != nil {
 			continue
 		}
 		m.LastPingAt = lp
 		m.SSHSyncedAt = ss
+		m.LastOfflineAt = lo
 		m.SSHPassword = models.NullString{} // never return password
 		if !isAdmin {
 			sanitizeMachine(&m)
@@ -113,8 +115,10 @@ func (h *MachineHandler) Get(c *gin.Context) {
 
 	var m models.Machine
 	var lp, ss *time.Time
-	err = db.DB.QueryRow(`SELECT id, hostname, ip, mac, os_type, os_version, notes, ssh_port, ssh_username, ssh_password, is_online, last_ping_at, cpu_info, memory_info, disk_info, uptime, listen_ports, ssh_synced_at, created_at, updated_at FROM machines WHERE id = ?`, id).
+	var lo *time.Time
-		Scan(&m.ID, &m.Hostname, &m.IP, &m.MAC, &m.OsType, &m.OsVersion, &m.Notes, &m.SSHPort, &m.SSHUsername, &m.SSHPassword, &m.IsOnline, &lp, &m.CPUInfo, &m.MemoryInfo, &m.DiskInfo, &m.Uptime, &m.ListenPorts, &ss, &m.CreatedAt, &m.UpdatedAt)
+	err = db.DB.QueryRow(`SELECT id, hostname, ip, mac, os_type, os_version, notes, ssh_port, ssh_username, ssh_password, is_online, last_ping_at, cpu_info, memory_info, disk_info, uptime, listen_ports, ssh_synced_at, offline_count, total_offline_seconds, last_offline_at, last_offline_reason, created_at, updated_at FROM machines WHERE id = ?`, id).
+		Scan(&m.ID, &m.Hostname, &m.IP, &m.MAC, &m.OsType, &m.OsVersion, &m.Notes, &m.SSHPort, &m.SSHUsername, &m.SSHPassword, &m.IsOnline, &lp, &m.CPUInfo, &m.MemoryInfo, &m.DiskInfo, &m.Uptime, &m.ListenPorts, &ss, &m.OfflineCount, &m.TotalOfflineSeconds, &lo, &m.LastOfflineReason, &m.CreatedAt, &m.UpdatedAt)
+	m.LastOfflineAt = lo
 	if err == sql.ErrNoRows {
 		c.JSON(http.StatusNotFound, gin.H{"error": "not found"})
 		return
@@ -165,6 +169,32 @@ func (h *MachineHandler) Get(c *gin.Context) {
 	})
 }
 
+func (h *MachineHandler) OfflineLogs(c *gin.Context) {
+	id, err := strconv.ParseInt(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid id"})
+		return
+	}
+	rows, err := db.DB.Query(`SELECT id, machine_id, reason, started_at, ended_at, duration_seconds FROM offline_logs WHERE machine_id = ? ORDER BY started_at DESC LIMIT 50`, id)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	defer rows.Close()
+	logs := []models.OfflineLog{}
+	for rows.Next() {
+		var l models.OfflineLog
+		var endedAt *time.Time
+		var dur *int
+		if err := rows.Scan(&l.ID, &l.MachineID, &l.Reason, &l.StartedAt, &endedAt, &dur); err == nil {
+			l.EndedAt = endedAt
+			l.DurationSeconds = dur
+			logs = append(logs, l)
+		}
+	}
+	c.JSON(http.StatusOK, logs)
+}
+
 func (h *MachineHandler) Create(c *gin.Context) {
 	var m models.Machine
 	if err := c.ShouldBindJSON(&m); err != nil {

server/main.go

@@ -77,6 +77,7 @@ func main() {
 			admin.DELETE("/machines/:id", mh.Delete)
 			admin.POST("/machines/:id/ssh-info", mh.SSHInfo)
 			admin.POST("/machines/:id/sync-ssh", mh.SyncSSH)
+			admin.GET("/machines/:id/offline-logs", mh.OfflineLogs)
 
 			sh := handlers.NewServiceHandler()
 			admin.GET("/machines/:id/services", sh.ListByMachine)

server/models/models.go

@@ -53,7 +53,20 @@ type Machine struct {
 	SSHSyncedAt  *time.Time `json:"ssh_synced_at"`
 	CreatedAt    time.Time  `json:"created_at"`
 	UpdatedAt    time.Time  `json:"updated_at"`
-	ServiceCount int        `json:"service_count"`
+	ServiceCount          int        `json:"service_count"`
+	OfflineCount          int        `json:"offline_count"`
+	TotalOfflineSeconds   int        `json:"total_offline_seconds"`
+	LastOfflineAt         *time.Time `json:"last_offline_at"`
+	LastOfflineReason     NullString `json:"last_offline_reason"`
+}
+
+type OfflineLog struct {
+	ID              int64      `json:"id"`
+	MachineID       int64      `json:"machine_id"`
+	Reason          string     `json:"reason"`
+	StartedAt       time.Time  `json:"started_at"`
+	EndedAt         *time.Time `json:"ended_at"`
+	DurationSeconds *int       `json:"duration_seconds"`
 }
 
 type Service struct {

server/services/ping.go

@@ -6,39 +6,74 @@ import (
 	"fmt"
 	"lan-manager/server/db"
 	"lan-manager/server/utils"
+	"net"
+	"os"
 	"os/exec"
 	"runtime"
 	"strings"
 	"time"
 
-	"net"
-
 	"golang.org/x/net/icmp"
 	"golang.org/x/net/ipv4"
 )
 
-func PingHost(ip string) bool {
+// PingResult holds connectivity status and failure reason
-	// Try system ping first (no special privileges needed on Linux)
+type PingResult struct {
+	Online bool
+	Reason string // empty if online, otherwise human-readable failure reason
+}
+
+func PingHost(ip string, port int) PingResult {
 	if ok := pingWithSystem(ip); ok {
-		return true
+		return PingResult{Online: true}
 	}
-	// Fallback to raw ICMP
+	if ok := pingWithICMP(ip); ok {
-	return pingWithICMP(ip)
+		return PingResult{Online: true}
+	}
+	if ok := pingWithTCP(ip, port); ok {
+		return PingResult{Online: true}
+	}
+	return PingResult{Online: false, Reason: "unreachable (ping/icmp/tcp all failed)"}
+}
+
+// PingHostRepeated pings the host up to retries times.
+// If any attempt succeeds, it returns online immediately.
+// Only if all retries fail does it return offline.
+func PingHostRepeated(ip string, port int, retries int) PingResult {
+	if retries <= 0 {
+		retries = 1
+	}
+	var lastReason string
+	for i := 0; i < retries; i++ {
+		if i > 0 {
+			time.Sleep(2 * time.Second)
+		}
+		res := PingHost(ip, port)
+		if res.Online {
+			return res
+		}
+		lastReason = res.Reason
+	}
+	return PingResult{Online: false, Reason: fmt.Sprintf("unreachable after %d retries (%s)", retries, lastReason)}
 }
 
 func pingWithSystem(ip string) bool {
 	var cmd *exec.Cmd
 	if runtime.GOOS == "windows" {
-		cmd = exec.Command("ping", "-n", "1", "-w", "3000", ip)
+		cmd = exec.Command("ping", "-n", "1", "-w", "5000", ip)
 	} else if runtime.GOOS == "darwin" {
-		// macOS ping -W is in milliseconds
+		cmd = exec.Command("ping", "-c", "1", "-W", "5000", ip)
-		cmd = exec.Command("ping", "-c", "1", "-W", "3000", ip)
 	} else {
-		// Linux ping -W is in seconds
+		cmd = exec.Command("ping", "-c", "1", "-W", "5", ip)
-		cmd = exec.Command("ping", "-c", "1", "-W", "3", ip)
 	}
-	err := cmd.Run()
+	out, err := cmd.CombinedOutput()
-	return err == nil
+	if err != nil {
+		if _, ok := err.(*exec.ExitError); !ok {
+			fmt.Printf("[Ping] system ping error for %s: %v, output: %s\n", ip, err, strings.TrimSpace(string(out)))
+		}
+		return false
+	}
+	return true
 }
 
 func pingWithICMP(ip string) bool {
@@ -48,10 +83,11 @@ func pingWithICMP(ip string) bool {
 	}
 	defer c.Close()
 
+	id := os.Getpid() & 0xffff
 	m := &icmp.Message{
 		Type: ipv4.ICMPTypeEcho,
 		Code: 0,
-		Body: &icmp.Echo{ID: 1, Seq: 1, Data: []byte("lan-manager")},
+		Body: &icmp.Echo{ID: id, Seq: 1, Data: []byte("lan-manager")},
 	}
 	wb, err := m.Marshal(nil)
 	if err != nil {
@@ -62,7 +98,7 @@ func pingWithICMP(ip string) bool {
 	}
 
 	rb := make([]byte, 1500)
-	_ = c.SetReadDeadline(time.Now().Add(3 * time.Second))
+	_ = c.SetReadDeadline(time.Now().Add(5 * time.Second))
 	n, _, err := c.ReadFrom(rb)
 	if err != nil {
 		return false
@@ -74,6 +110,19 @@ func pingWithICMP(ip string) bool {
 	return rm.Type == ipv4.ICMPTypeEchoReply
 }
 
+func pingWithTCP(ip string, port int) bool {
+	if port <= 0 {
+		port = 22
+	}
+	addr := fmt.Sprintf("%s:%d", ip, port)
+	conn, err := net.DialTimeout("tcp", addr, 3*time.Second)
+	if err != nil {
+		return false
+	}
+	_ = conn.Close()
+	return true
+}
+
 func parseIP(ip string) []byte {
 	parts := strings.Split(ip, ".")
 	if len(parts) != 4 {
@@ -88,77 +137,127 @@ func parseIP(ip string) []byte {
 	return res
 }
 
+type machinePing struct {
+	id          int64
+	ip          string
+	sshPort     int
+	sshUsername string
+	sshPassword string
+	wasOnline   bool
+}
+
+func handlePingResult(m *machinePing, res PingResult) {
+	online := res.Online
+	reason := res.Reason
+	var onlineInt int
+	if online {
+		onlineInt = 1
+	}
+
+	// State transition: online -> offline
+	if m.wasOnline && !online {
+		_, dbErr := db.DB.Exec(`UPDATE machines SET is_online=0, last_ping_at=CURRENT_TIMESTAMP, offline_count=offline_count+1, last_offline_at=CURRENT_TIMESTAMP, last_offline_reason=? WHERE id=?`,
+			reason, m.id)
+		if dbErr != nil {
+			fmt.Printf("[Ping] update status error for %s: %v\n", m.ip, dbErr)
+		} else {
+			fmt.Printf("[Ping] %s -> online=false, reason=%s\n", m.ip, reason)
+		}
+		_, _ = db.DB.Exec(`INSERT INTO offline_logs (machine_id, reason, started_at) VALUES (?, ?, CURRENT_TIMESTAMP)`, m.id, reason)
+		m.wasOnline = false
+		return
+	}
+
+	// State transition: offline -> online
+	if !m.wasOnline && online {
+		_, dbErr := db.DB.Exec(`UPDATE machines SET is_online=1, last_ping_at=CURRENT_TIMESTAMP, last_offline_reason='' WHERE id=?`, m.id)
+		if dbErr != nil {
+			fmt.Printf("[Ping] update status error for %s: %v\n", m.ip, dbErr)
+		} else {
+			fmt.Printf("[Ping] %s -> online=true\n", m.ip)
+		}
+		var logID int64
+		var startedAt time.Time
+		row := db.DB.QueryRow(`SELECT id, started_at FROM offline_logs WHERE machine_id=? AND ended_at IS NULL ORDER BY started_at DESC LIMIT 1`, m.id)
+		if err := row.Scan(&logID, &startedAt); err == nil {
+			duration := int(time.Since(startedAt).Seconds())
+			_, _ = db.DB.Exec(`UPDATE offline_logs SET ended_at=CURRENT_TIMESTAMP, duration_seconds=? WHERE id=?`, duration, logID)
+			_, _ = db.DB.Exec(`UPDATE machines SET total_offline_seconds=total_offline_seconds+? WHERE id=?`, duration, m.id)
+		}
+		m.wasOnline = true
+		return
+	}
+
+	// No state change
+	_, dbErr := db.DB.Exec(`UPDATE machines SET is_online=?, last_ping_at=CURRENT_TIMESTAMP WHERE id=?`, onlineInt, m.id)
+	if dbErr != nil {
+		fmt.Printf("[Ping] update status error for %s: %v\n", m.ip, dbErr)
+	} else {
+		fmt.Printf("[Ping] %s -> online=%v\n", m.ip, online)
+	}
+
+	if online && m.sshUsername != "" && m.sshPassword != "" {
+		go func(mid int64, mip string, mport int, muser, mpass string) {
+			plainPass, decryptErr := utils.Decrypt(mpass)
+			if decryptErr != nil {
+				fmt.Printf("[SSH] decrypt failed for %s:%d: %v\n", mip, mport, decryptErr)
+				return
+			}
+			result, err := GetSSHInfo(mip, mport, muser, plainPass)
+			if err != nil {
+				fmt.Printf("[SSH] auto-fetch failed for %s:%d: %v\n", mip, mport, err)
+				return
+			}
+			portsStr := ""
+			if len(result.ListenPorts) > 0 {
+				b, _ := json.Marshal(result.ListenPorts)
+				portsStr = string(b)
+				if len(portsStr) > 2 {
+					portsStr = portsStr[1 : len(portsStr)-1]
+				}
+			}
+			_, dbErr := db.DB.Exec(`UPDATE machines SET cpu_info=?, memory_info=?, disk_info=?, uptime=?, listen_ports=?, ssh_synced_at=CURRENT_TIMESTAMP, updated_at=CURRENT_TIMESTAMP WHERE id=?`,
+				result.RawCPUInfo, result.RawMemoryInfo, result.RawDiskInfo, result.Uptime, portsStr, mid)
+			if dbErr != nil {
+				fmt.Printf("[SSH] auto-fetch db error for %s:%d: %v\n", mip, mport, dbErr)
+			} else {
+				fmt.Printf("[SSH] auto-fetch success for %s:%d\n", mip, mport)
+			}
+		}(m.id, m.ip, m.sshPort, m.sshUsername, m.sshPassword)
+	}
+}
+
 func StartPingService(interval int) {
-	ticker := time.NewTicker(time.Duration(interval) * time.Second)
+	const step = 30 * time.Second
+
 	go func() {
-		for range ticker.C {
+		time.Sleep(2 * time.Second)
-			rows, err := db.DB.Query(`SELECT id, ip, ssh_port, ssh_username, ssh_password FROM machines`)
+
+		for {
+			rows, err := db.DB.Query(`SELECT id, ip, ssh_port, ssh_username, ssh_password, is_online FROM machines ORDER BY id ASC`)
 			if err != nil {
 				fmt.Printf("[Ping] query error: %v\n", err)
+				time.Sleep(step)
 				continue
 			}
-			type machinePing struct {
+
-				id            int64
-				ip            string
-				sshPort       int
-				sshUsername   string
-				sshPassword   string
-			}
 			list := []machinePing{}
 			for rows.Next() {
 				var m machinePing
-				if err := rows.Scan(&m.id, &m.ip, &m.sshPort, &m.sshUsername, &m.sshPassword); err == nil {
+				var isOnline int
+				if err := rows.Scan(&m.id, &m.ip, &m.sshPort, &m.sshUsername, &m.sshPassword, &isOnline); err == nil {
+					m.wasOnline = isOnline == 1
 					list = append(list, m)
-				} else {
-					fmt.Printf("[Ping] scan error: %v\n", err)
 				}
 			}
 			rows.Close()
-			fmt.Printf("[Ping] tick processed %d machines\n", len(list))
 
-			for _, m := range list {
+			fmt.Printf("[Ping] start round, %d machines, interval %v each\n", len(list), step)
-				online := PingHost(m.ip)
-				var onlineInt int
-				if online {
-					onlineInt = 1
-				}
-				_, dbErr := db.DB.Exec(`UPDATE machines SET is_online = ?, last_ping_at = CURRENT_TIMESTAMP WHERE id = ?`, onlineInt, m.id)
-				if dbErr != nil {
-					fmt.Printf("[Ping] update status error for %s: %v\n", m.ip, dbErr)
-				} else {
-					fmt.Printf("[Ping] %s -> online=%v\n", m.ip, online)
-				}
 
-				// Auto fetch SSH info if credentials are saved
+			for i := range list {
-				if m.sshUsername != "" && m.sshPassword != "" {
+				res := PingHostRepeated(list[i].ip, list[i].sshPort, 3)
-					go func(mid int64, mip string, mport int, muser, mpass string) {
+				handlePingResult(&list[i], res)
-						plainPass, decryptErr := utils.Decrypt(mpass)
+				time.Sleep(step)
-						if decryptErr != nil {
-							fmt.Printf("[SSH] decrypt failed for %s:%d: %v\n", mip, mport, decryptErr)
-							return
-						}
-						result, err := GetSSHInfo(mip, mport, muser, plainPass)
-						if err != nil {
-							fmt.Printf("[SSH] auto-fetch failed for %s:%d: %v\n", mip, mport, err)
-							return
-						}
-						portsStr := ""
-						if len(result.ListenPorts) > 0 {
-							b, _ := json.Marshal(result.ListenPorts)
-							portsStr = string(b)
-							if len(portsStr) > 2 {
-								portsStr = portsStr[1 : len(portsStr)-1]
-							}
-						}
-						_, dbErr := db.DB.Exec(`UPDATE machines SET cpu_info=?, memory_info=?, disk_info=?, uptime=?, listen_ports=?, ssh_synced_at=CURRENT_TIMESTAMP, updated_at=CURRENT_TIMESTAMP WHERE id=?`,
-							result.RawCPUInfo, result.RawMemoryInfo, result.RawDiskInfo, result.Uptime, portsStr, mid)
-						if dbErr != nil {
-							fmt.Printf("[SSH] auto-fetch db error for %s:%d: %v\n", mip, mport, dbErr)
-						} else {
-							fmt.Printf("[SSH] auto-fetch success for %s:%d\n", mip, mport)
-						}
-					}(m.id, m.ip, m.sshPort, m.sshUsername, m.sshPassword)
-				}
 			}
 		}
 	}()
@@ -175,7 +274,8 @@ func CleanupLogs(ctx context.Context, retentionDays int) {
 			case <-ctx.Done():
 				return
 			case <-ticker.C:
-				_, _ = db.DB.Exec(`DELETE FROM operation_logs WHERE created_at < datetime('now', '-`+fmt.Sprintf("%d", retentionDays)+` days')`)
+				_, _ = db.DB.Exec(`DELETE FROM operation_logs WHERE created_at < datetime('now', '-` + fmt.Sprintf("%d", retentionDays) + ` days')`)
+				_, _ = db.DB.Exec(`DELETE FROM offline_logs WHERE started_at < datetime('now', '-` + fmt.Sprintf("%d", retentionDays) + ` days')`)
 			}
 		}
 	}()

web/src/App.vue

@@ -3,24 +3,64 @@
 </template>
 
 <script setup>
+import { onMounted } from 'vue'
+
+onMounted(() => {
+  const saved = localStorage.getItem('theme')
+  if (saved) {
+    document.documentElement.classList.toggle('dark', saved === 'dark')
+  } else if (window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches) {
+    document.documentElement.classList.add('dark')
+  }
+})
 </script>
 
 <style>
-/* CSS Variables */
+/* Light mode (default) */
 :root {
-  --bg: #f6f7f9;
+  --bg: #f8fafc;
   --surface: #ffffff;
-  --text: #111827;
+  --surface-hover: #f8fafc;
-  --text-secondary: #4b5563;
+  --text: #0f172a;
-  --text-muted: #9ca3af;
+  --text-secondary: #475569;
-  --border: #e5e7eb;
+  --text-muted: #94a3b8;
+  --border: #e2e8f0;
+  --border-strong: #cbd5e1;
   --primary: #3b82f6;
   --primary-weak: #eff6ff;
   --success: #22c55e;
   --warning: #f59e0b;
   --danger: #ef4444;
   --radius: 14px;
-  --shadow: 0 6px 24px rgba(0,0,0,0.04);
+  --shadow: 0 1px 3px rgba(2, 8, 23, 0.05), 0 1px 2px rgba(2, 8, 23, 0.03);
+  --shadow-lg: 0 10px 30px rgba(2, 8, 23, 0.08);
+
+  --pill-bg: #0f172a;
+  --pill-text: #f8fafc;
+  --pill-border: rgba(255,255,255,0.06);
+}
+
+/* Dark mode */
+html.dark {
+  --bg: #020617;
+  --surface: #0f172a;
+  --surface-hover: #1e293b;
+  --text: #f8fafc;
+  --text-secondary: #94a3b8;
+  --text-muted: #64748b;
+  --border: #1e293b;
+  --border-strong: #334155;
+  --primary: #60a5fa;
+  --primary-weak: rgba(59,130,246,0.15);
+  --success: #34d399;
+  --warning: #fbbf24;
+  --danger: #f87171;
+  --shadow: 0 1px 3px rgba(0, 0, 0, 0.4), 0 1px 2px rgba(0, 0, 0, 0.3);
+  --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.5);
+
+  --pill-bg: #1e293b;
+  --pill-text: #f8fafc;
+  --pill-border: #334155;
 }
 
 * { box-sizing: border-box; }
@@ -33,6 +73,7 @@ html, body, #app {
   background: var(--bg);
   color: var(--text);
   -webkit-font-smoothing: antialiased;
+  transition: background .2s ease, color .2s ease;
 }
 
 .page {
@@ -48,6 +89,7 @@ html, body, #app {
   box-shadow: var(--shadow);
   border: 1px solid var(--border);
   margin-bottom: 16px;
+  transition: background .2s ease, border-color .2s ease;
 }
 
 .card-title {
@@ -60,7 +102,7 @@ html, body, #app {
   justify-content: space-between;
 }
 
-/* Element Plus overrides for a softer look */
+/* Element Plus overrides */
 .el-button {
   border-radius: 8px;
   font-weight: 500;
@@ -71,6 +113,12 @@ html, body, #app {
   --el-button-hover-bg-color: #2563eb;
   --el-button-hover-border-color: #2563eb;
 }
+html.dark .el-button--primary {
+  --el-button-bg-color: #3b82f6;
+  --el-button-border-color: #3b82f6;
+  --el-button-hover-bg-color: #2563eb;
+  --el-button-hover-border-color: #2563eb;
+}
 .el-input__wrapper {
   border-radius: 10px;
 }
@@ -88,8 +136,8 @@ html, body, #app {
   padding: 10px 20px 18px;
 }
 .el-table {
-  --el-table-header-bg-color: #f9fafb;
+  --el-table-header-bg-color: var(--surface-hover);
-  --el-table-row-hover-bg-color: #f3f4f6;
+  --el-table-row-hover-bg-color: var(--surface-hover);
   --el-table-border-color: var(--border);
   border-radius: 10px;
   overflow: hidden;
@@ -111,9 +159,12 @@ html, body, #app {
   height: 8px;
 }
 ::-webkit-scrollbar-thumb {
-  background: rgba(0,0,0,0.12);
+  background: rgba(128,128,128,0.25);
   border-radius: 4px;
 }
+html.dark ::-webkit-scrollbar-thumb {
+  background: rgba(148,163,184,0.25);
+}
 ::-webkit-scrollbar-track {
   background: transparent;
 }

web/src/api/index.js

@@ -43,6 +43,7 @@ export const updateMachine = (id, data) => api.put(`/machines/${id}`, data)
 export const deleteMachine = (id) => api.delete(`/machines/${id}`)
 export const sshInfo = (id, data) => api.post(`/machines/${id}/ssh-info`, data)
 export const syncSSH = (id, data) => api.post(`/machines/${id}/sync-ssh`, data)
+export const fetchOfflineLogs = (id) => api.get(`/machines/${id}/offline-logs`)
 
 export const fetchServices = (machineId) => api.get(`/machines/${machineId}/services`)
 export const fetchAllServices = () => api.get('/services')

web/src/components/MainLayout.vue

@@ -19,6 +19,10 @@
           <span>操作日志</span>
         </router-link>
       </nav>
+      <div class="theme-toggle" @click="toggleTheme">
+        <el-icon class="theme-icon"><component :is="isDark ? Sunny : Moon" /></el-icon>
+        <span>{{ isDark ? '浅色模式' : '深色模式' }}</span>
+      </div>
       <div class="sidebar-footer">
         <div class="user-info">
           <el-icon class="user-icon"><User /></el-icon>
@@ -40,15 +44,26 @@
 </template>
 
 <script setup>
-import { computed } from 'vue'
+import { computed, ref, onMounted } from 'vue'
 import { useRouter } from 'vue-router'
-import { Monitor, Share, Document, User, SwitchButton } from '@element-plus/icons-vue'
+import { Monitor, Share, Document, User, SwitchButton, Sunny, Moon } from '@element-plus/icons-vue'
 import { getAuth, refreshAuth } from '@/router'
 import { logout as apiLogout } from '@/api'
 import { ElMessage } from 'element-plus'
 
 const router = useRouter()
 const isAdmin = computed(() => getAuth().is_admin)
+const isDark = ref(false)
+
+onMounted(() => {
+  isDark.value = document.documentElement.classList.contains('dark')
+})
+
+function toggleTheme() {
+  isDark.value = !isDark.value
+  document.documentElement.classList.toggle('dark', isDark.value)
+  localStorage.setItem('theme', isDark.value ? 'dark' : 'light')
+}
 
 async function logout() {
   try {
@@ -182,6 +197,26 @@ async function logout() {
   padding: 10px;
 }
 
+.theme-toggle {
+  margin: 0 10px 10px;
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  padding: 10px 12px;
+  border-radius: 8px;
+  color: rgba(255,255,255,0.55);
+  font-size: 13px;
+  cursor: pointer;
+  transition: background .15s ease, color .15s ease;
+}
+.theme-toggle:hover {
+  background: rgba(255,255,255,0.06);
+  color: rgba(255,255,255,0.9);
+}
+.theme-icon {
+  font-size: 16px;
+}
+
 .main.no-sidebar {
   margin-left: 0;
 }

web/src/main.js

@@ -1,6 +1,7 @@
 import { createApp } from 'vue'
 import ElementPlus from 'element-plus'
 import 'element-plus/dist/index.css'
+import 'element-plus/theme-chalk/dark/css-vars.css'
 import * as ElementPlusIconsVue from '@element-plus/icons-vue'
 import App from './App.vue'
 import router from './router'

web/src/views/MachineDetail.vue

@@ -138,6 +138,34 @@
         <el-empty v-else description="暂无服务" :image-size="80" />
       </div>
 
+      <!-- Offline Stats & Logs -->
+      <div class="card" v-if="isAdmin">
+        <div class="card-title">离线统计</div>
+        <div class="offline-stats">
+          <div class="stat-box">
+            <div class="stat-num">{{ machine.offline_count || 0 }}</div>
+            <div class="stat-label">离线次数</div>
+          </div>
+          <div class="stat-box">
+            <div class="stat-num">{{ formatDuration(machine.total_offline_seconds) }}</div>
+            <div class="stat-label">累计离线时长</div>
+          </div>
+          <div class="stat-box" v-if="machine.last_offline_reason">
+            <div class="stat-reason">{{ machine.last_offline_reason }}</div>
+            <div class="stat-label">上次离线原因</div>
+          </div>
+        </div>
+        <div v-if="offlineLogs.length" class="offline-logs">
+          <div class="log-title">最近离线记录</div>
+          <div v-for="log in offlineLogs.slice(0, 5)" :key="log.id" class="log-row">
+            <span class="log-time">{{ formatTime(log.started_at) }}</span>
+            <span class="log-reason">{{ log.reason || '未知原因' }}</span>
+            <span class="log-dur" v-if="log.duration_seconds !== null && log.duration_seconds !== undefined">持续 {{ formatDuration(log.duration_seconds) }}</span>
+            <span class="log-dur pending" v-else>未恢复</span>
+          </div>
+        </div>
+      </div>
+
       <!-- Relationships -->
       <div class="card" v-if="isAdmin">
         <div class="card-title">
@@ -278,7 +306,7 @@ import {
   fetchMachine, updateMachine, deleteMachine,
   fetchServices, createService, updateService, deleteService,
   fetchRelationships, createRelationship, updateRelationship, deleteRelationship,
-  sshInfo, syncSSH, fetchMachines,
+  sshInfo, syncSSH, fetchMachines, fetchOfflineLogs,
   checkAuth, uiRefreshInterval,
 } from '@/api'
 import { getAuth } from '@/router'
@@ -293,6 +321,7 @@ const machine = ref(null)
 const services = ref([])
 const relationships = ref([])
 const allMachines = ref([])
+const offlineLogs = ref([])
 
 const dialogVisible = ref(false)
 const editing = ref({})
@@ -343,6 +372,10 @@ onUnmounted(() => {
 async function loadMachine() {
   const res = await fetchMachine(machineId)
   machine.value = res.data.machine
+  if (isAdmin) {
+    const logsRes = await fetchOfflineLogs(machineId)
+    offlineLogs.value = logsRes.data
+  }
   // 如果已有同步过的 SSH 信息，直接展示上次结果
   if (machine.value && (machine.value.cpu_info || machine.value.memory_info || machine.value.disk_info || machine.value.uptime)) {
     sshResult.value = {
@@ -544,6 +577,20 @@ function formatTime(t) {
   const pad = n => String(n).padStart(2, '0')
   return `${d.getFullYear()}-${pad(d.getMonth()+1)}-${pad(d.getDate())} ${pad(d.getHours())}:${pad(d.getMinutes())}:${pad(d.getSeconds())}`
 }
+
+function formatDuration(seconds) {
+  if (!seconds && seconds !== 0) return '-'
+  const s = Number(seconds)
+  if (s < 60) return `${s}秒`
+  if (s < 3600) return `${Math.floor(s / 60)}分${s % 60}秒`
+  const h = Math.floor(s / 3600)
+  const m = Math.floor((s % 3600) / 60)
+  const sec = s % 60
+  if (h < 24) return `${h}时${m}分`
+  const d = Math.floor(h / 24)
+  const hr = h % 24
+  return `${d}天${hr}时${m}分`
+}
 </script>
 
 <style scoped>
@@ -572,8 +619,10 @@ function formatTime(t) {
   border-radius: 999px;
   font-weight: 600;
 }
-.status-badge.online { background: #dcfce7; color: #166534; }
+.status-badge.online { background: rgba(34,197,94,0.12); color: #15803d; }
-.status-badge.offline { background: #fee2e2; color: #991b1b; }
+.status-badge.offline { background: rgba(239,68,68,0.10); color: #b91c1c; }
+html.dark .status-badge.online { background: rgba(52,211,153,0.15); color: #34d399; }
+html.dark .status-badge.offline { background: rgba(248,113,113,0.15); color: #f87171; }
 .host-subtitle {
   margin-top: 4px;
   font-size: 13px;
@@ -610,9 +659,10 @@ function formatTime(t) {
   justify-content: space-between;
   align-items: center;
   padding: 8px 10px;
-  background: #f9fafb;
+  background: var(--surface-hover);
   border-radius: 8px;
   font-size: 13px;
+  transition: background .2s ease;
 }
 .info-label { color: var(--text-secondary); }
 .info-value { font-weight: 500; color: var(--text); }
@@ -628,8 +678,9 @@ function formatTime(t) {
   align-items: center;
   gap: 12px;
   padding: 12px;
-  background: #f9fafb;
+  background: var(--surface-hover);
   border-radius: 10px;
+  transition: background .2s ease;
 }
 .sp-icon {
   width: 36px; height: 36px; border-radius: 8px;
@@ -642,7 +693,7 @@ function formatTime(t) {
 .sp-icon.disk { background: linear-gradient(135deg, #f59e0b, #fbbf24); }
 .sp-info { flex: 1; min-width: 0; }
 .sp-title { font-size: 12px; color: var(--text-secondary); margin-bottom: 6px; }
-.sp-bar { height: 5px; background: #e5e7eb; border-radius: 3px; overflow: hidden; }
+.sp-bar { height: 5px; background: var(--border-strong); border-radius: 3px; overflow: hidden; }
 .sp-fill { height: 100%; border-radius: 3px; background: #3b82f6; transition: width .3s ease; }
 .sp-num { font-size: 14px; font-weight: 700; color: var(--text); min-width: 36px; text-align: right; }
 
@@ -673,7 +724,7 @@ function formatTime(t) {
 }
 .dd-bar {
   height: 5px;
-  background: #e5e7eb;
+  background: var(--border-strong);
   border-radius: 3px;
   overflow: hidden;
 }
@@ -689,8 +740,9 @@ function formatTime(t) {
   font-size: 13px;
   color: var(--text-secondary);
   padding: 8px 10px;
-  background: #f9fafb;
+  background: var(--surface-hover);
   border-radius: 8px;
+  transition: background .2s ease;
 }
 
 .sync-actions {
@@ -700,9 +752,10 @@ function formatTime(t) {
   margin-bottom: 12px;
 }
 .ssh-result {
-  background: #f9fafb;
+  background: var(--surface-hover);
   border-radius: 10px;
   padding: 12px;
+  transition: background .2s ease;
 }
 .result-grid {
   display: grid;
@@ -730,9 +783,10 @@ function formatTime(t) {
   justify-content: space-between;
   gap: 12px;
   padding: 10px 12px;
-  background: #f9fafb;
+  background: var(--surface-hover);
   border-radius: 10px;
   flex-wrap: wrap;
+  transition: background .2s ease;
 }
 .service-main {
   display: flex;
@@ -746,7 +800,7 @@ function formatTime(t) {
 .service-port {
   font-size: 12px;
   color: var(--text-muted);
-  background: #fff;
+  background: var(--surface);
   padding: 1px 6px;
   border-radius: 4px;
   border: 1px solid var(--border);
@@ -777,9 +831,10 @@ function formatTime(t) {
   justify-content: space-between;
   gap: 12px;
   padding: 10px 12px;
-  background: #f9fafb;
+  background: var(--surface-hover);
   border-radius: 10px;
   flex-wrap: wrap;
+  transition: background .2s ease;
 }
 .rel-arrow {
   display: flex;
@@ -797,7 +852,7 @@ function formatTime(t) {
   font-size: 12px;
 }
 .rel-port {
-  background: #fff;
+  background: var(--surface);
   padding: 1px 6px;
   border-radius: 4px;
   border: 1px solid var(--border);
@@ -810,4 +865,71 @@ function formatTime(t) {
   display: flex;
   gap: 6px;
 }
+
+.offline-stats {
+  display: grid;
+  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
+  gap: 12px;
+  margin-bottom: 16px;
+}
+.stat-box {
+  background: var(--surface-hover);
+  border-radius: 10px;
+  padding: 12px;
+  text-align: center;
+}
+.stat-num {
+  font-size: 20px;
+  font-weight: 700;
+  color: var(--text);
+}
+.stat-reason {
+  font-size: 13px;
+  font-weight: 600;
+  color: var(--danger);
+  word-break: break-all;
+}
+.stat-label {
+  font-size: 12px;
+  color: var(--text-muted);
+  margin-top: 4px;
+}
+
+.offline-logs {
+  background: var(--surface-hover);
+  border-radius: 10px;
+  padding: 12px;
+}
+.log-title {
+  font-size: 13px;
+  font-weight: 600;
+  color: var(--text-secondary);
+  margin-bottom: 10px;
+}
+.log-row {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  padding: 8px 0;
+  border-bottom: 1px solid var(--border);
+  font-size: 12px;
+}
+.log-row:last-child {
+  border-bottom: none;
+}
+.log-time {
+  color: var(--text-muted);
+  min-width: 140px;
+}
+.log-reason {
+  flex: 1;
+  color: var(--text-secondary);
+}
+.log-dur {
+  color: var(--text);
+  font-weight: 500;
+}
+.log-dur.pending {
+  color: var(--warning);
+}
 </style>

web/src/views/MachineList.vue

@@ -20,11 +20,12 @@
 
     <!-- Cards -->
     <div class="cards-grid">
-      <div v-for="m in machines" :key="m.id" class="server-card" :class="[osClass(m.os_type), { 'guest-card': !isAdmin, 'offline-card': !m.is_online }]" @click="isAdmin && goDetail(m.id)">
+      <div v-for="m in machines" :key="m.id" class="server-card" :class="[{ 'guest-card': !isAdmin, 'offline-card': !m.is_online }]" @click="isAdmin && goDetail(m.id)">
         <div class="card-header">
           <div class="title-row">
-            <span class="status-dot" :class="m.is_online ? 'online' : 'offline'"></span>
+            <span class="os-dot" :class="osClass(m.os_type)" :title="m.os_type"></span>
             <span class="hostname">{{ m.hostname }}</span>
+            <span class="status-badge" :class="m.is_online ? 'online' : 'offline'">{{ m.is_online ? '在线' : '离线' }}</span>
             <el-tag v-if="m.service_count" size="small" effect="plain" class="svc-tag" round>服务 {{ m.service_count }}</el-tag>
           </div>
           <div class="meta-row">
@@ -343,25 +344,15 @@ function formatTime(t) {
   padding: 18px;
   box-shadow: var(--shadow);
   border: 1px solid var(--border);
-  border-left-width: 4px;
+  border-top-width: 3px;
+  border-top-color: var(--border-strong);
   cursor: pointer;
-  transition: transform .12s ease, box-shadow .2s ease, opacity .2s ease;
+  transition: transform .12s ease, box-shadow .2s ease, opacity .2s ease, border-color .2s ease;
-}
-.server-card.os-linux { border-left-color: #3b82f6; background: linear-gradient(90deg, rgba(59,130,246,0.04) 0%, var(--surface) 20px); }
-.server-card.os-windows { border-left-color: #22c55e; background: linear-gradient(90deg, rgba(34,197,94,0.04) 0%, var(--surface) 20px); }
-.server-card.os-macos { border-left-color: #a855f7; background: linear-gradient(90deg, rgba(168,85,247,0.04) 0%, var(--surface) 20px); }
-.server-card.os-other { border-left-color: #6b7280; background: linear-gradient(90deg, rgba(107,114,128,0.04) 0%, var(--surface) 20px); }
-
-.server-card.offline-card {
-  opacity: 0.72;
-  filter: grayscale(0.45);
-}
-.server-card.offline-card .hostname {
-  color: var(--text-secondary);
 }
 .server-card:hover {
   transform: translateY(-2px);
-  box-shadow: 0 8px 30px rgba(0,0,0,0.06);
+  box-shadow: var(--shadow-lg);
+  border-color: var(--border-strong);
 }
 .server-card.guest-card {
   cursor: default;
@@ -369,6 +360,15 @@ function formatTime(t) {
 .server-card.guest-card:hover {
   transform: none;
   box-shadow: var(--shadow);
+  border-color: var(--border);
+}
+
+.server-card.offline-card {
+  opacity: 0.65;
+  border-top-color: var(--border);
+}
+.server-card.offline-card .hostname {
+  color: var(--text-muted);
 }
 
 .card-header {
@@ -381,11 +381,42 @@ function formatTime(t) {
   align-items: center;
   gap: 10px;
 }
-.status-dot {
+.os-dot {
-  width: 8px; height: 8px; border-radius: 50%;
+  width: 10px;
+  height: 10px;
+  border-radius: 50%;
+  flex-shrink: 0;
+  box-shadow: inset 0 0 0 1px rgba(0,0,0,0.08);
 }
-.status-dot.online { background: var(--success); box-shadow: 0 0 0 3px rgba(34,197,94,.18); }
+.os-dot.os-linux { background: #3b82f6; }
-.status-dot.offline { background: var(--danger); box-shadow: 0 0 0 3px rgba(239,68,68,.18); }
+.os-dot.os-windows { background: #22c55e; }
+.os-dot.os-macos { background: #a855f7; }
+.os-dot.os-other { background: #64748b; }
+
+.status-badge {
+  font-size: 11px;
+  padding: 2px 8px;
+  border-radius: 999px;
+  font-weight: 600;
+  line-height: 1;
+}
+.status-badge.online {
+  background: rgba(34,197,94,0.12);
+  color: #15803d;
+}
+.status-badge.offline {
+  background: rgba(239,68,68,0.10);
+  color: #b91c1c;
+}
+html.dark .status-badge.online {
+  background: rgba(52,211,153,0.15);
+  color: #34d399;
+}
+html.dark .status-badge.offline {
+  background: rgba(248,113,113,0.15);
+  color: #f87171;
+}
+
 .hostname {
   font-weight: 700;
   font-size: 15px;
@@ -410,7 +441,8 @@ function formatTime(t) {
 .meta-ip {
   color: var(--text);
   font-weight: 500;
-  background: #f3f4f6;
+  background: var(--surface-hover);
+  border: 1px solid var(--border);
   padding: 1px 6px;
   border-radius: 4px;
 }
@@ -429,24 +461,26 @@ function formatTime(t) {
   gap: 10px;
 }
 .stat-pill {
-  background: linear-gradient(180deg, rgba(17,24,39,0.72), rgba(17,24,39,0.62));
+  background: var(--pill-bg);
-  border-radius: 12px;
+  border: 1px solid var(--pill-border);
-  padding: 10px;
+  border-radius: 10px;
-  color: #fff;
+  padding: 9px 10px;
+  color: var(--pill-text);
   display: flex;
   align-items: center;
   gap: 8px;
+  transition: background .2s ease, border-color .2s ease;
 }
 .pill-icon {
-  width: 24px; height: 24px; border-radius: 6px;
+  width: 22px; height: 22px; border-radius: 5px;
   display: flex; align-items: center; justify-content: center;
   font-size: 10px; font-weight: 800;
-  background: rgba(255,255,255,0.12);
+  background: rgba(255,255,255,0.10);
   flex-shrink: 0;
 }
-.pill-icon.cpu { color: #a5f3fc; }
+.pill-icon.cpu { color: #7dd3fc; }
-.pill-icon.mem { color: #bbf7d0; }
+.pill-icon.mem { color: #86efac; }
-.pill-icon.disk { color: #bfdbfe; }
+.pill-icon.disk { color: #93c5fd; }
 .pill-body {
   flex: 1; display: flex; flex-direction: column; gap: 4px; min-width: 0;
 }

web/src/views/Topology.vue

@@ -21,7 +21,7 @@
 </template>
 
 <script setup>
-import { onMounted, ref } from 'vue'
+import { onMounted, ref, onUnmounted } from 'vue'
 import { Graph } from '@antv/g6'
 import { Plus } from '@element-plus/icons-vue'
 import { fetchMachines, fetchAllServices as fetchServicesAll, fetchRelationships } from '@/api'
@@ -29,6 +29,70 @@ import { getAuth } from '@/router'
 
 const isAdmin = getAuth().is_admin
 let graph = null
+let observer = null
+
+function getIsDark() {
+  return document.documentElement.classList.contains('dark')
+}
+
+function themeFill() {
+  return getIsDark() ? '#0f172a' : '#ffffff'
+}
+
+function themeText() {
+  return getIsDark() ? '#f8fafc' : '#111827'
+}
+
+function themeBg() {
+  return getIsDark() ? '#020617' : '#fafafa'
+}
+
+function renderGraph() {
+  const container = document.getElementById('topo')
+  if (!container || !graph) return
+  container.style.background = themeBg()
+  graph.getNodes().forEach(node => {
+    const model = node.getModel()
+    graph.updateItem(node, {
+      style: {
+        fill: themeFill(),
+        stroke: osColor(model.os),
+        lineWidth: 2,
+        radius: 8,
+        shadowColor: getIsDark() ? 'rgba(0,0,0,0.5)' : 'rgba(0,0,0,0.06)',
+        shadowBlur: 8,
+        shadowOffsetY: 2
+      },
+      labelCfg: {
+        style: { fill: themeText(), fontSize: 13, fontWeight: 600 }
+      },
+      badgeCfg: {
+        position: 'topRight',
+        style: {
+          fill: model.online ? '#22c55e' : '#ef4444',
+          stroke: themeFill(),
+          lineWidth: 2
+        }
+      }
+    })
+  })
+  graph.getEdges().forEach(edge => {
+    const model = edge.getModel()
+    const isRel = String(model.id).startsWith('rel-')
+    const color = isRel ? '#f97316' : '#3b82f6'
+    graph.updateItem(edge, {
+      labelCfg: {
+        style: {
+          fill: color,
+          fontSize: 11,
+          fontWeight: 500,
+          background: { fill: themeFill(), padding: [2, 4], radius: 4 }
+        }
+      }
+    })
+  })
+  graph.paint()
+}
 
 onMounted(async () => {
   const [machinesRes, servicesRes, relsRes] = await Promise.all([
@@ -44,28 +108,32 @@ onMounted(async () => {
   const machineMap = {}
   machines.forEach(m => machineMap[m.id] = m)
 
+  const isDark = getIsDark()
+  const fill = themeFill()
+  const text = themeText()
+
   const nodes = machines.map(m => ({
     id: String(m.id),
     label: m.hostname,
     online: m.is_online,
     os: m.os_type,
     style: {
-      fill: '#ffffff',
+      fill,
       stroke: osColor(m.os_type),
       lineWidth: 2,
       radius: 8,
-      shadowColor: 'rgba(0,0,0,0.06)',
+      shadowColor: isDark ? 'rgba(0,0,0,0.5)' : 'rgba(0,0,0,0.06)',
       shadowBlur: 8,
       shadowOffsetY: 2
     },
     labelCfg: {
-      style: { fill: '#111827', fontSize: 13, fontWeight: 600 }
+      style: { fill: text, fontSize: 13, fontWeight: 600 }
     },
     badgeCfg: {
       position: 'topRight',
       style: {
         fill: m.is_online ? '#22c55e' : '#ef4444',
-        stroke: '#fff',
+        stroke: fill,
         lineWidth: 2
       }
     }
@@ -87,7 +155,7 @@ onMounted(async () => {
         endArrow: { path: 'M 0,0 L 8,4 L 8,-4 Z', fill: '#f97316' }
       },
       labelCfg: {
-        style: { fill: '#f97316', fontSize: 11, fontWeight: 500, background: { fill: '#fff', padding: [2, 4], radius: 4 } }
+        style: { fill: '#f97316', fontSize: 11, fontWeight: 500, background: { fill, padding: [2, 4], radius: 4 } }
       }
     })
   })
@@ -105,16 +173,19 @@ onMounted(async () => {
           endArrow: { path: 'M 0,0 L 8,4 L 8,-4 Z', fill: '#3b82f6' }
         },
         labelCfg: {
-          style: { fill: '#3b82f6', fontSize: 11, fontWeight: 500, background: { fill: '#fff', padding: [2, 4], radius: 4 } }
+          style: { fill: '#3b82f6', fontSize: 11, fontWeight: 500, background: { fill, padding: [2, 4], radius: 4 } }
         }
       })
     }
   })
 
+  const container = document.getElementById('topo')
+  container.style.background = themeBg()
+
   graph = new Graph({
     container: 'topo',
-    width: document.getElementById('topo').clientWidth,
+    width: container.clientWidth,
-    height: document.getElementById('topo').clientHeight,
+    height: container.clientHeight,
     layout: {
       type: 'force',
       preventOverlap: true,
@@ -144,12 +215,26 @@ onMounted(async () => {
   })
 
   window.addEventListener('resize', () => {
-    const container = document.getElementById('topo')
+    const c = document.getElementById('topo')
-    if (container && graph) {
+    if (c && graph) {
-      graph.changeSize(container.clientWidth, container.clientHeight)
+      graph.changeSize(c.clientWidth, c.clientHeight)
       graph.fitView()
     }
   })
+
+  // Watch for theme changes
+  observer = new MutationObserver(() => {
+    renderGraph()
+  })
+  observer.observe(document.documentElement, { attributes: true, attributeFilter: ['class'] })
+})
+
+onUnmounted(() => {
+  if (observer) observer.disconnect()
+  if (graph) {
+    graph.destroy()
+    graph = null
+  }
 })
 
 function highlightNode(nodeId) {
@@ -222,21 +307,22 @@ function relLabel(r) {
   height: 100%;
   border-radius: 10px;
   overflow: hidden;
-  background: #fafafa;
+  transition: background .2s ease;
 }
 
 .legend {
   position: absolute;
   left: 16px;
   bottom: 16px;
-  background: rgba(255,255,255,0.95);
+  background: var(--surface);
   border: 1px solid var(--border);
   border-radius: 10px;
   padding: 10px 12px;
   display: flex;
   gap: 14px;
-  box-shadow: 0 6px 20px rgba(0,0,0,0.05);
+  box-shadow: var(--shadow);
   backdrop-filter: blur(6px);
+  transition: background .2s ease, border-color .2s ease;
 }
 .legend-item {
   display: flex;