diff --git a/backend/internal/handler/admin/dashboard_handler.go b/backend/internal/handler/admin/dashboard_handler.go
index 460f6357..e9fbb630 100644
--- a/backend/internal/handler/admin/dashboard_handler.go
+++ b/backend/internal/handler/admin/dashboard_handler.go
@@ -546,9 +546,14 @@ func (h *DashboardHandler) GetBatchUsersUsage(c *gin.Context) {
 		return
 	}
 
+	// cacheKey 必须包含当日日期，否则跨午夜后 30s 内会复用昨天的 "today_*" 结果。
 	keyRaw, _ := json.Marshal(struct {
+		V       int     `json:"v"`
+		Day     string  `json:"day"`
 		UserIDs []int64 `json:"user_ids"`
 	}{
+		V:       2, // bump 当响应结构变化（如加入 by_platform 时）
+		Day:     timezone.Today().Format("2006-01-02"),
 		UserIDs: userIDs,
 	})
 	cacheKey := string(keyRaw)
diff --git a/backend/internal/pkg/usagestats/usage_log_types.go b/backend/internal/pkg/usagestats/usage_log_types.go
index fe5f98d6..39283d22 100644
--- a/backend/internal/pkg/usagestats/usage_log_types.go
+++ b/backend/internal/pkg/usagestats/usage_log_types.go
@@ -230,6 +230,20 @@ type UserDashboardStats struct {
 	// 性能指标
 	Rpm int64 `json:"rpm"` // 近5分钟平均每分钟请求数
 	Tpm int64 `json:"tpm"` // 近5分钟平均每分钟Token数
+
+	// 按"有效平台"维度拆分（与 ops 路径口径一致：group.platform 优先，否则 account.platform）
+	ByPlatform []PlatformDashboardStats `json:"by_platform,omitempty"`
+}
+
+// PlatformDashboardStats 单个平台的用量明细。
+type PlatformDashboardStats struct {
+	Platform        string  `json:"platform"`
+	TotalRequests   int64   `json:"total_requests"`
+	TotalTokens     int64   `json:"total_tokens"`
+	TotalActualCost float64 `json:"total_actual_cost"`
+	TodayRequests   int64   `json:"today_requests"`
+	TodayTokens     int64   `json:"today_tokens"`
+	TodayActualCost float64 `json:"today_actual_cost"`
 }
 
 // UsageLogFilters represents filters for usage log queries
@@ -265,13 +279,22 @@ type UsageStats struct {
 	EndpointPaths     []EndpointStat `json:"endpoint_paths,omitempty"`
 }
 
-// BatchUserUsageStats represents usage stats for a single user
-type BatchUserUsageStats struct {
-	UserID          int64   `json:"user_id"`
+// PlatformUsage 表示某用户/某 API key 在单个"有效平台"维度的用量明细。
+// Platform 取值与 ops 路径口径一致：优先 groups.platform，否则 accounts.platform。
+type PlatformUsage struct {
+	Platform        string  `json:"platform"`
 	TodayActualCost float64 `json:"today_actual_cost"`
 	TotalActualCost float64 `json:"total_actual_cost"`
 }
 
+// BatchUserUsageStats represents usage stats for a single user
+type BatchUserUsageStats struct {
+	UserID          int64           `json:"user_id"`
+	TodayActualCost float64         `json:"today_actual_cost"`
+	TotalActualCost float64         `json:"total_actual_cost"`
+	ByPlatform      []PlatformUsage `json:"by_platform,omitempty"`
+}
+
 // BatchAPIKeyUsageStats represents usage stats for a single API key
 type BatchAPIKeyUsageStats struct {
 	APIKeyID        int64   `json:"api_key_id"`
diff --git a/backend/internal/repository/usage_log_repo.go b/backend/internal/repository/usage_log_repo.go
index c4f35d4d..f11910a0 100644
--- a/backend/internal/repository/usage_log_repo.go
+++ b/backend/internal/repository/usage_log_repo.go
@@ -96,6 +96,22 @@ const rawUsageLogModelColumn = "model"
 // Historical rows may contain upstream/billing model values, while newer rows store requested_model.
 // Requested/upstream/mapping analytics must use resolveModelDimensionExpression instead.
 
+// usageLogSuccessFilterUL 用于把"失败请求 usage log"（tokens=0、cost=0、不计费的占位记录）
+// 从统计性聚合中排除，避免污染 Dashboard / 用量拆分等指标。
+//
+// schema 中没有 success bool 列；新增列要做迁移，风险大；这里用 actual_cost > 0 作为代理：
+// 任何成功落账的请求都会产生 actual_cost（包括 token 计费、纯图片 token 计费、按次/按图计费），
+// 反之 failed-request usage log 的 actual_cost 为 0。
+// 早期版本用 4 项 token 和 > 0 判定会把"按次/按图计费"与"image_output_tokens 独立计费"的纯图片
+// 请求误判为失败，导致这部分请求从用量统计里消失，故改用 actual_cost。
+// 配合 `FROM usage_logs ul` JOIN 查询使用。
+const usageLogSuccessFilterUL = "ul.actual_cost > 0"
+
+// usageLogEffectivePlatformExpr 用于按"有效平台"维度聚合 usage_logs：
+// 优先取请求实际走的分组 platform，若分组未设置 platform 再 fallback 到 account.platform。
+// 配套要求查询里 LEFT JOIN groups g ON g.id = ul.group_id 与 LEFT JOIN accounts a ON a.id = ul.account_id。
+const usageLogEffectivePlatformExpr = "COALESCE(NULLIF(g.platform,''), a.platform)"
+
 // dateFormatWhitelist 将 granularity 参数映射为 PostgreSQL TO_CHAR 格式字符串，防止外部输入直接拼入 SQL
 var dateFormatWhitelist = map[string]string{
 	"hour":  "YYYY-MM-DD HH24:00",
@@ -2414,6 +2430,9 @@ func (r *usageLogRepository) GetUserSpendingRanking(ctx context.Context, startTi
 // UserDashboardStats 用户仪表盘统计
 type UserDashboardStats = usagestats.UserDashboardStats
 
+// PlatformDashboardStats 单平台用量明细
+type PlatformDashboardStats = usagestats.PlatformDashboardStats
+
 // GetUserDashboardStats 获取用户专属的仪表盘统计
 func (r *usageLogRepository) GetUserDashboardStats(ctx context.Context, userID int64) (*UserDashboardStats, error) {
 	stats := &UserDashboardStats{}
@@ -2509,6 +2528,57 @@ func (r *usageLogRepository) GetUserDashboardStats(ctx context.Context, userID i
 	stats.Rpm = rpm
 	stats.Tpm = tpm
 
+	// 按"有效平台"维度拆分（group.platform 优先，否则 account.platform）。
+	// 与 ops 路径口径一致；HAVING 过滤掉无法确定平台的行（避免出现空字符串平台）。
+	// 与上面 totalStatsQuery/todayStatsQuery 的总值可能略微差异，原因有二：
+	//   1) 无平台归属的极少数行（group/account 都没 platform）会被 HAVING 排除；
+	//   2) usageLogSuccessFilterUL 会把 actual_cost = 0 的失败 placeholder 行排除，
+	//      而 totalStatsQuery/todayStatsQuery 没有这层过滤、会把这些行的 request 计数算进去。
+	platformQuery := `
+		SELECT
+			` + usageLogEffectivePlatformExpr + ` as platform,
+			COUNT(*) as total_requests,
+			COALESCE(SUM(ul.input_tokens + ul.output_tokens + ul.cache_creation_tokens + ul.cache_read_tokens), 0) as total_tokens,
+			COALESCE(SUM(ul.actual_cost), 0) as total_actual_cost,
+			COUNT(*) FILTER (WHERE ul.created_at >= $2) as today_requests,
+			COALESCE(SUM(ul.input_tokens + ul.output_tokens + ul.cache_creation_tokens + ul.cache_read_tokens) FILTER (WHERE ul.created_at >= $2), 0) as today_tokens,
+			COALESCE(SUM(ul.actual_cost) FILTER (WHERE ul.created_at >= $2), 0) as today_actual_cost
+		FROM usage_logs ul
+		LEFT JOIN groups g ON g.id = ul.group_id
+		LEFT JOIN accounts a ON a.id = ul.account_id
+		WHERE ul.user_id = $1
+		  AND ` + usageLogSuccessFilterUL + `
+		GROUP BY ` + usageLogEffectivePlatformExpr + `
+		HAVING ` + usageLogEffectivePlatformExpr + ` IS NOT NULL AND ` + usageLogEffectivePlatformExpr + ` <> ''
+		ORDER BY total_actual_cost DESC
+	`
+	rows, err := r.sql.QueryContext(ctx, platformQuery, userID, today)
+	if err != nil {
+		return nil, err
+	}
+	for rows.Next() {
+		var p PlatformDashboardStats
+		if err := rows.Scan(
+			&p.Platform,
+			&p.TotalRequests,
+			&p.TotalTokens,
+			&p.TotalActualCost,
+			&p.TodayRequests,
+			&p.TodayTokens,
+			&p.TodayActualCost,
+		); err != nil {
+			_ = rows.Close()
+			return nil, err
+		}
+		stats.ByPlatform = append(stats.ByPlatform, p)
+	}
+	if err := rows.Close(); err != nil {
+		return nil, err
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+
 	return stats, nil
 }
 
@@ -2769,6 +2839,9 @@ type UsageStats = usagestats.UsageStats
 // BatchUserUsageStats represents usage stats for a single user
 type BatchUserUsageStats = usagestats.BatchUserUsageStats
 
+// PlatformUsage represents per-platform usage breakdown
+type PlatformUsage = usagestats.PlatformUsage
+
 func normalizePositiveInt64IDs(ids []int64) []int64 {
 	if len(ids) == 0 {
 		return nil
@@ -2809,15 +2882,21 @@ func (r *usageLogRepository) GetBatchUserUsageStats(ctx context.Context, userIDs
 		result[id] = &BatchUserUsageStats{UserID: id}
 	}
 
+	// GROUP BY (user_id, effective_platform) 一次查询同时得到总值与按平台拆分。
+	// 应用层把同一 user_id 的多行累加为总值，并把非空 platform 行收集到 ByPlatform。
 	query := `
 		SELECT
-			user_id,
-			COALESCE(SUM(actual_cost) FILTER (WHERE created_at >= $2 AND created_at < $3), 0) as total_cost,
-			COALESCE(SUM(actual_cost) FILTER (WHERE created_at >= $4), 0) as today_cost
-		FROM usage_logs
-		WHERE user_id = ANY($1)
-		  AND created_at >= LEAST($2, $4)
-		GROUP BY user_id
+			ul.user_id,
+			` + usageLogEffectivePlatformExpr + ` as platform,
+			COALESCE(SUM(ul.actual_cost) FILTER (WHERE ul.created_at >= $2 AND ul.created_at < $3), 0) as total_cost,
+			COALESCE(SUM(ul.actual_cost) FILTER (WHERE ul.created_at >= $4), 0) as today_cost
+		FROM usage_logs ul
+		LEFT JOIN groups g ON g.id = ul.group_id
+		LEFT JOIN accounts a ON a.id = ul.account_id
+		WHERE ul.user_id = ANY($1)
+		  AND ul.created_at >= LEAST($2, $4)
+		  AND ` + usageLogSuccessFilterUL + `
+		GROUP BY ul.user_id, ` + usageLogEffectivePlatformExpr + `
 	`
 	today := timezone.Today()
 	rows, err := r.sql.QueryContext(ctx, query, pq.Array(normalizedUserIDs), startTime, endTime, today)
@@ -2826,15 +2905,25 @@ func (r *usageLogRepository) GetBatchUserUsageStats(ctx context.Context, userIDs
 	}
 	for rows.Next() {
 		var userID int64
+		var platform sql.NullString
 		var total float64
 		var todayTotal float64
-		if err := rows.Scan(&userID, &total, &todayTotal); err != nil {
+		if err := rows.Scan(&userID, &platform, &total, &todayTotal); err != nil {
 			_ = rows.Close()
 			return nil, err
 		}
-		if stats, ok := result[userID]; ok {
-			stats.TotalActualCost = total
-			stats.TodayActualCost = todayTotal
+		stats, ok := result[userID]
+		if !ok {
+			continue
+		}
+		stats.TotalActualCost += total
+		stats.TodayActualCost += todayTotal
+		if platform.Valid && platform.String != "" {
+			stats.ByPlatform = append(stats.ByPlatform, PlatformUsage{
+				Platform:        platform.String,
+				TotalActualCost: total,
+				TodayActualCost: todayTotal,
+			})
 		}
 	}
 	if err := rows.Close(); err != nil {
diff --git a/frontend/src/api/admin/dashboard.ts b/frontend/src/api/admin/dashboard.ts
index 49e487b7..dda7d892 100644
--- a/frontend/src/api/admin/dashboard.ts
+++ b/frontend/src/api/admin/dashboard.ts
@@ -266,10 +266,17 @@ export async function getUserSpendingRanking(
   return data
 }
 
+export interface PlatformUsage {
+  platform: string
+  today_actual_cost: number
+  total_actual_cost: number
+}
+
 export interface BatchUserUsageStats {
   user_id: number
   today_actual_cost: number
   total_actual_cost: number
+  by_platform?: PlatformUsage[]
 }
 
 export interface BatchUsersUsageResponse {
diff --git a/frontend/src/api/usage.ts b/frontend/src/api/usage.ts
index 802c428f..7169b698 100644
--- a/frontend/src/api/usage.ts
+++ b/frontend/src/api/usage.ts
@@ -15,6 +15,16 @@ import type {
 
 // ==================== Dashboard Types ====================
 
+export interface PlatformDashboardStats {
+  platform: string
+  total_requests: number
+  total_tokens: number
+  total_actual_cost: number
+  today_requests: number
+  today_tokens: number
+  today_actual_cost: number
+}
+
 export interface UserDashboardStats {
   total_api_keys: number
   active_api_keys: number
@@ -37,6 +47,7 @@ export interface UserDashboardStats {
   average_duration_ms: number
   rpm: number // 近5分钟平均每分钟请求数
   tpm: number // 近5分钟平均每分钟Token数
+  by_platform?: PlatformDashboardStats[]
 }
 
 export interface TrendParams {
diff --git a/frontend/src/components/user/PlatformCostCell.vue b/frontend/src/components/user/PlatformCostCell.vue
new file mode 100644
index 00000000..dd5de111
--- /dev/null
+++ b/frontend/src/components/user/PlatformCostCell.vue
@@ -0,0 +1,24 @@
+<template>
+  <div v-if="usage" class="text-sm">
+    <div class="flex items-center gap-1.5">
+      <span class="text-gray-500 dark:text-gray-400">{{ t('admin.users.today') }}:</span>
+      <span class="font-medium text-gray-900 dark:text-white">${{ usage.today_actual_cost.toFixed(4) }}</span>
+    </div>
+    <div class="mt-0.5 flex items-center gap-1.5">
+      <span class="text-gray-500 dark:text-gray-400">{{ t('admin.users.total') }}:</span>
+      <span class="font-medium text-gray-900 dark:text-white">${{ usage.total_actual_cost.toFixed(4) }}</span>
+    </div>
+  </div>
+  <span v-else class="text-sm text-gray-400 dark:text-gray-500">—</span>
+</template>
+
+<script setup lang="ts">
+import { useI18n } from 'vue-i18n'
+import type { PlatformUsage } from '@/api/admin/dashboard'
+
+defineProps<{
+  usage?: PlatformUsage
+}>()
+
+const { t } = useI18n()
+</script>
diff --git a/frontend/src/components/user/PlatformUsageBreakdown.vue b/frontend/src/components/user/PlatformUsageBreakdown.vue
new file mode 100644
index 00000000..e995bc01
--- /dev/null
+++ b/frontend/src/components/user/PlatformUsageBreakdown.vue
@@ -0,0 +1,103 @@
+<template>
+  <div class="group/usage relative text-sm">
+    <div class="flex items-center gap-1.5">
+      <span class="text-gray-500 dark:text-gray-400">{{ t('admin.users.today') }}:</span>
+      <span class="font-medium text-gray-900 dark:text-white">${{ today.toFixed(4) }}</span>
+      <Icon
+        v-if="hasBreakdown"
+        name="infoCircle"
+        size="xs"
+        class="text-gray-400 dark:text-gray-500"
+      />
+    </div>
+    <div class="mt-0.5 flex items-center gap-1.5">
+      <span class="text-gray-500 dark:text-gray-400">{{ t('admin.users.total') }}:</span>
+      <span class="font-medium text-gray-900 dark:text-white">${{ total.toFixed(4) }}</span>
+    </div>
+
+    <div
+      v-if="hasBreakdown"
+      class="pointer-events-none absolute left-full top-0 z-50 ml-2 min-w-[220px] whitespace-nowrap rounded-md bg-gray-900 px-3 py-2 text-xs text-white opacity-0 shadow-xl transition-opacity duration-100 group-hover/usage:opacity-100 dark:bg-dark-600"
+    >
+      <div class="mb-1.5 flex items-center justify-between gap-3 border-b border-white/10 pb-1 text-[11px] opacity-80">
+        <span>{{ t('admin.users.platformBreakdown') }}</span>
+        <span class="font-mono">{{ t('admin.users.today') }} / {{ t('admin.users.total') }}</span>
+      </div>
+      <div
+        v-for="item in sortedBreakdown"
+        :key="item.platform"
+        class="flex items-center justify-between gap-3 py-0.5"
+        :class="{ 'opacity-70 italic': item.isOther }"
+      >
+        <span class="capitalize">
+          {{ item.isOther ? t('admin.users.platformOther') : platformLabel(item.platform) }}
+        </span>
+        <span class="font-mono">
+          ${{ item.today_actual_cost.toFixed(4) }}
+          <span class="opacity-50">/</span>
+          ${{ item.total_actual_cost.toFixed(4) }}
+        </span>
+      </div>
+    </div>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { computed } from 'vue'
+import { useI18n } from 'vue-i18n'
+import Icon from '@/components/icons/Icon.vue'
+import type { PlatformUsage } from '@/api/admin/dashboard'
+
+const props = defineProps<{
+  today: number
+  total: number
+  byPlatform?: PlatformUsage[]
+}>()
+
+const { t } = useI18n()
+
+// 与 UserDashboardStats 保持一致：把"总值 - 各平台之和"的差作为"其他"行展示，
+// 避免 tooltip 内各平台费用加总与列首总值对不上。
+const OTHER_THRESHOLD = 0.0001
+
+interface BreakdownRow {
+  platform: string
+  today_actual_cost: number
+  total_actual_cost: number
+  isOther?: boolean
+}
+
+const sortedBreakdown = computed<BreakdownRow[]>(() => {
+  const list = props.byPlatform ?? []
+  const rows: BreakdownRow[] = [...list]
+    .sort((a, b) => b.total_actual_cost - a.total_actual_cost)
+    .map((p) => ({ ...p }))
+
+  const sumTotal = rows.reduce((s, r) => s + r.total_actual_cost, 0)
+  const sumToday = rows.reduce((s, r) => s + r.today_actual_cost, 0)
+  const diffTotal = Math.max(0, props.total - sumTotal)
+  const diffToday = Math.max(0, props.today - sumToday)
+  if (diffTotal > OTHER_THRESHOLD || diffToday > OTHER_THRESHOLD) {
+    rows.push({
+      platform: '__other__',
+      today_actual_cost: diffToday,
+      total_actual_cost: diffTotal,
+      isOther: true
+    })
+  }
+  return rows
+})
+
+const hasBreakdown = computed(() => sortedBreakdown.value.length > 0)
+
+const PLATFORM_LABELS: Record<string, string> = {
+  anthropic: 'Claude',
+  openai: 'OpenAI',
+  gemini: 'Gemini',
+  antigravity: 'Antigravity'
+}
+
+function platformLabel(platform: string): string {
+  return PLATFORM_LABELS[platform] ?? platform
+}
+</script>
diff --git a/frontend/src/components/user/dashboard/UserDashboardStats.vue b/frontend/src/components/user/dashboard/UserDashboardStats.vue
index dfba3a51..97d2da3d 100644
--- a/frontend/src/components/user/dashboard/UserDashboardStats.vue
+++ b/frontend/src/components/user/dashboard/UserDashboardStats.vue
@@ -131,20 +131,118 @@
       </div>
     </div>
   </div>
+
+  <!-- Row 3: Per-platform breakdown -->
+  <div v-if="!isSimple && platformCards.length > 0" class="card p-4">
+    <div class="mb-3 flex items-center justify-between">
+      <h3 class="text-sm font-semibold text-gray-900 dark:text-white">{{ t('dashboard.platformBreakdown') }}</h3>
+      <span class="text-xs text-gray-500 dark:text-gray-400">
+        {{ t('dashboard.platformCount', { count: sortedPlatforms.length }) }}
+      </span>
+    </div>
+    <div class="grid grid-cols-1 gap-3 sm:grid-cols-2 lg:grid-cols-4">
+      <div
+        v-for="item in platformCards"
+        :key="item.platform"
+        :class="[
+          'rounded-lg border p-3',
+          item.isOther
+            ? 'border-dashed border-gray-300 bg-gray-50 dark:border-dark-500 dark:bg-dark-700/30'
+            : 'border-gray-200 dark:border-dark-600'
+        ]"
+      >
+        <div class="flex items-center justify-between">
+          <span class="text-sm font-semibold text-gray-900 dark:text-white">
+            {{ item.isOther ? t('dashboard.platformOther') : platformLabel(item.platform) }}
+          </span>
+          <span class="font-mono text-sm text-purple-600 dark:text-purple-400" :title="t('dashboard.actual')">
+            ${{ formatCost(item.total_actual_cost) }}
+          </span>
+        </div>
+        <div class="mt-2 space-y-1 text-xs">
+          <div class="flex items-center justify-between">
+            <span class="text-gray-500 dark:text-gray-400">{{ t('dashboard.todayCost') }}</span>
+            <span class="font-mono text-gray-900 dark:text-white">${{ formatCost(item.today_actual_cost) }}</span>
+          </div>
+          <div class="flex items-center justify-between">
+            <span class="text-gray-500 dark:text-gray-400">{{ t('dashboard.requests') }}</span>
+            <span class="font-mono text-gray-700 dark:text-gray-300">
+              {{ item.total_requests > 0 ? formatNumber(item.total_requests) : '-' }}
+            </span>
+          </div>
+          <div class="flex items-center justify-between">
+            <span class="text-gray-500 dark:text-gray-400">{{ t('dashboard.tokens') }}</span>
+            <span class="font-mono text-gray-700 dark:text-gray-300">
+              {{ item.total_tokens > 0 ? formatTokens(item.total_tokens) : '-' }}
+            </span>
+          </div>
+        </div>
+      </div>
+    </div>
+  </div>
 </template>
 
 <script setup lang="ts">
+import { computed } from 'vue'
 import { useI18n } from 'vue-i18n'
 import Icon from '@/components/icons/Icon.vue'
 import type { UserDashboardStats as UserStatsType } from '@/api/usage'
 
-defineProps<{
+const props = defineProps<{
   stats: UserStatsType
   balance: number
   isSimple: boolean
 }>()
 const { t } = useI18n()
 
+const PLATFORM_LABELS: Record<string, string> = {
+  anthropic: 'Claude',
+  openai: 'OpenAI',
+  gemini: 'Gemini',
+  antigravity: 'Antigravity'
+}
+
+const platformLabel = (p: string) => PLATFORM_LABELS[p] ?? p
+
+const sortedPlatforms = computed(() => {
+  const list = props.stats?.by_platform ?? []
+  return [...list].sort((a, b) => b.total_actual_cost - a.total_actual_cost)
+})
+
+// 处理"各平台之和 < 总值"的差值：后端按平台聚合时过滤了无法归属平台的行
+// （group 与 account 都缺 platform）。这里把差值作为"其他"卡片显式展示，
+// 避免 Row 1 总值与 Row 3 平台拆分加总对不上、用户困惑。
+const OTHER_THRESHOLD = 0.0001
+const platformCards = computed(() => {
+  const cards: Array<{
+    platform: string
+    total_actual_cost: number
+    today_actual_cost: number
+    total_requests: number
+    total_tokens: number
+    isOther?: boolean
+  }> = sortedPlatforms.value.map((p) => ({ ...p }))
+
+  const total = props.stats?.total_actual_cost ?? 0
+  const today = props.stats?.today_actual_cost ?? 0
+  const sumTotal = cards.reduce((s, c) => s + c.total_actual_cost, 0)
+  const sumToday = cards.reduce((s, c) => s + c.today_actual_cost, 0)
+  const diffTotal = Math.max(0, total - sumTotal)
+  const diffToday = Math.max(0, today - sumToday)
+
+  if (diffTotal > OTHER_THRESHOLD || diffToday > OTHER_THRESHOLD) {
+    cards.push({
+      platform: '__other__',
+      total_actual_cost: diffTotal,
+      today_actual_cost: diffToday,
+      total_requests: 0,
+      total_tokens: 0,
+      isOther: true
+    })
+  }
+  return cards
+})
+
 const formatBalance = (b: number) =>
   new Intl.NumberFormat('en-US', {
     minimumFractionDigits: 2,
diff --git a/frontend/src/i18n/locales/en.ts b/frontend/src/i18n/locales/en.ts
index eb373e16..f5b51a64 100644
--- a/frontend/src/i18n/locales/en.ts
+++ b/frontend/src/i18n/locales/en.ts
@@ -595,6 +595,10 @@ export default {
     hour: 'Hour',
     modelDistribution: 'Model Distribution',
     groupDistribution: 'Group Usage Distribution',
+    platformBreakdown: 'Per-platform Breakdown',
+    platformBreakdownEmpty: 'No platform usage yet',
+    platformCount: '{count} platforms',
+    platformOther: 'Other',
     tokenUsageTrend: 'Token Usage Trend',
     noDataAvailable: 'No data available',
     model: 'Model',
@@ -1754,6 +1758,10 @@ export default {
         subscriptions: 'Subscriptions',
         balance: 'Balance',
         usage: 'Usage',
+        usageAnthropic: 'Usage (Claude)',
+        usageOpenAI: 'Usage (OpenAI)',
+        usageGemini: 'Usage (Gemini)',
+        usageAntigravity: 'Usage (Antigravity)',
         concurrency: 'Concurrency',
         status: 'Status',
         lastActive: 'Last Active',
@@ -1763,6 +1771,8 @@ export default {
       },
       today: 'Today',
       total: 'Last 30d',
+      sortBy: 'Sort By',
+      sortCurrentPageOnly: 'Sorts current page only',
       noSubscription: 'No subscription',
       publicGroupCount: '+{count} public',
       exclusiveLabel: 'exclusive',
@@ -1855,6 +1865,12 @@ export default {
       // Balance History
       balanceHistory: 'Recharge History',
       balanceHistoryTip: 'Click to open recharge history',
+      columnAlwaysVisible: 'This column is always visible',
+      // Per-platform usage breakdown (hover tooltip)
+      platformBreakdown: 'Per-platform breakdown',
+      platformBreakdownEmpty: 'No platform usage yet',
+      platformBreakdownHint: 'Hover for per-platform usage',
+      platformOther: 'Other',
       balanceHistoryTitle: 'User Recharge & Concurrency History',
       noBalanceHistory: 'No records found for this user',
       allTypes: 'All Types',
diff --git a/frontend/src/i18n/locales/zh.ts b/frontend/src/i18n/locales/zh.ts
index ca3b4879..6a65f990 100644
--- a/frontend/src/i18n/locales/zh.ts
+++ b/frontend/src/i18n/locales/zh.ts
@@ -594,6 +594,10 @@ export default {
     hour: '按小时',
     modelDistribution: '模型分布',
     groupDistribution: '分组使用分布',
+    platformBreakdown: '按平台拆分',
+    platformBreakdownEmpty: '暂无平台用量',
+    platformCount: '{count} 个平台',
+    platformOther: '其他',
     tokenUsageTrend: 'Token 使用趋势',
     noDataAvailable: '暂无数据',
     model: '模型',
@@ -1775,6 +1779,10 @@ export default {
         subscriptions: '订阅分组',
         balance: '余额',
         usage: '用量',
+        usageAnthropic: '用量 (Claude)',
+        usageOpenAI: '用量 (OpenAI)',
+        usageGemini: '用量 (Gemini)',
+        usageAntigravity: '用量 (Antigravity)',
         concurrency: '并发数',
         status: '状态',
         lastActive: '最后活跃时间',
@@ -1784,6 +1792,8 @@ export default {
       },
       today: '今日',
       total: '近30天',
+      sortBy: '排序方式',
+      sortCurrentPageOnly: '仅对本页数据排序',
       noSubscription: '暂无订阅',
       publicGroupCount: '+{count} 公开',
       exclusiveLabel: '专属',
@@ -1912,6 +1922,12 @@ export default {
       // 余额变动记录
       balanceHistory: '充值记录',
       balanceHistoryTip: '点击查看充值记录',
+      columnAlwaysVisible: '该列固定显示，不可隐藏',
+      // 平台用量明细（悬浮显示）
+      platformBreakdown: '按平台拆分',
+      platformBreakdownEmpty: '暂无平台明细',
+      platformBreakdownHint: '悬浮查看各平台用量',
+      platformOther: '其他',
       balanceHistoryTitle: '用户充值和并发变动记录',
       noBalanceHistory: '暂无变动记录',
       allTypes: '全部类型',
diff --git a/frontend/src/views/admin/UsersView.vue b/frontend/src/views/admin/UsersView.vue
index ea67f695..512bae67 100644
--- a/frontend/src/views/admin/UsersView.vue
+++ b/frontend/src/views/admin/UsersView.vue
@@ -199,15 +199,22 @@
                   <button
                     v-for="col in toggleableColumns"
                     :key="col.key"
+                    :disabled="isForcedVisibleColumn(col.key)"
                     @click="toggleColumn(col.key)"
-                    class="flex w-full items-center justify-between px-4 py-2 text-left text-sm text-gray-700 hover:bg-gray-100 dark:text-gray-300 dark:hover:bg-dark-700"
+                    :class="[
+                      'flex w-full items-center justify-between px-4 py-2 text-left text-sm',
+                      isForcedVisibleColumn(col.key)
+                        ? 'cursor-not-allowed text-gray-400 dark:text-gray-500'
+                        : 'text-gray-700 hover:bg-gray-100 dark:text-gray-300 dark:hover:bg-dark-700'
+                    ]"
+                    :title="isForcedVisibleColumn(col.key) ? t('admin.users.columnAlwaysVisible') : ''"
                   >
                     <span>{{ col.label }}</span>
                     <Icon
                       v-if="isColumnVisible(col.key)"
                       name="check"
                       size="sm"
-                      class="text-primary-500"
+                      :class="isForcedVisibleColumn(col.key) ? 'text-gray-400 dark:text-gray-500' : 'text-primary-500'"
                       :stroke-width="2"
                     />
                   </button>
@@ -237,7 +244,7 @@
       <template #table>
         <DataTable
           :columns="columns"
-          :data="users"
+          :data="sortedUsers"
           :loading="loading"
           :actions-count="7"
           :server-side-sort="true"
@@ -413,23 +420,109 @@
             </div>
           </template>
 
-          <template #cell-usage="{ row }">
-            <div class="text-sm">
-              <div class="flex items-center gap-1.5">
-                <span class="text-gray-500 dark:text-gray-400">{{ t('admin.users.today') }}:</span>
-                <span class="font-medium text-gray-900 dark:text-white">
-                  ${{ (usageStats[row.id]?.today_actual_cost ?? 0).toFixed(4) }}
-                </span>
-              </div>
-              <div class="mt-0.5 flex items-center gap-1.5">
-                <span class="text-gray-500 dark:text-gray-400">{{ t('admin.users.total') }}:</span>
-                <span class="font-medium text-gray-900 dark:text-white">
-                  ${{ (usageStats[row.id]?.total_actual_cost ?? 0).toFixed(4) }}
-                </span>
+          <!-- 用量列自定义表头：列名 + 单个排序图标按钮，点击展开"今日/近30天"菜单。
+               column.sortable=false，DataTable 内置点击逻辑不会触发；
+               菜单项三态循环：desc → asc → off。 -->
+          <template
+            v-for="usageKey in USAGE_COLUMN_KEYS"
+            :key="usageKey"
+            #[`header-${usageKey}`]="{ column }"
+          >
+            <div class="flex items-center gap-1.5">
+              <span>{{ column.label }}</span>
+              <div class="usage-sort-trigger relative">
+                <button
+                  type="button"
+                  class="flex items-center gap-1 rounded px-1 py-0.5 transition-colors hover:bg-gray-200 dark:hover:bg-dark-700"
+                  :class="usageSort && usageSort.key === usageKey
+                    ? 'text-primary-600 dark:text-primary-400'
+                    : 'text-gray-400 dark:text-dark-500'"
+                  :title="t('admin.users.sortBy')"
+                  @click.stop="toggleUsageSortMenu(usageKey)"
+                >
+                  <span
+                    v-if="usageSort && usageSort.key === usageKey"
+                    class="text-[10px] normal-case font-medium tracking-normal"
+                  >{{ usageSort.metric === 'today' ? t('admin.users.today') : t('admin.users.total') }}</span>
+                  <svg
+                    v-if="usageSort && usageSort.key === usageKey"
+                    class="h-3.5 w-3.5"
+                    :class="{ 'rotate-180': usageSort.order === 'desc' }"
+                    fill="currentColor"
+                    viewBox="0 0 20 20"
+                  >
+                    <path
+                      fill-rule="evenodd"
+                      d="M14.707 12.707a1 1 0 01-1.414 0L10 9.414l-3.293 3.293a1 1 0 01-1.414-1.414l4-4a1 1 0 011.414 0l4 4a1 1 0 010 1.414z"
+                      clip-rule="evenodd"
+                    />
+                  </svg>
+                  <svg v-else class="h-3.5 w-3.5" fill="currentColor" viewBox="0 0 20 20">
+                    <path d="M10 3l-4 5h8l-4-5zM10 17l4-5H6l4 5z" />
+                  </svg>
+                </button>
+                <!-- 弹出菜单：今日 / 近30天，点击进行三态循环切换。 -->
+                <div
+                  v-if="openUsageSortMenu === usageKey"
+                  class="absolute right-0 top-full z-50 mt-1 min-w-[120px] rounded-lg border border-gray-200 bg-white py-1 shadow-lg dark:border-dark-600 dark:bg-dark-800"
+                >
+                  <button
+                    v-for="metric in (['today', 'total'] as const)"
+                    :key="metric"
+                    type="button"
+                    class="flex w-full items-center justify-between gap-3 px-3 py-1.5 text-left text-xs normal-case tracking-normal hover:bg-gray-100 dark:hover:bg-dark-700"
+                    :class="isUsageSortActive(usageKey, metric)
+                      ? 'font-medium text-primary-600 dark:text-primary-400'
+                      : 'text-gray-700 dark:text-gray-300'"
+                    @click.stop="toggleUsageSort(usageKey, metric)"
+                  >
+                    <span>{{ metric === 'today' ? t('admin.users.today') : t('admin.users.total') }}</span>
+                    <svg
+                      v-if="getUsageSortOrder(usageKey, metric)"
+                      class="h-3 w-3"
+                      :class="{ 'rotate-180': getUsageSortOrder(usageKey, metric) === 'desc' }"
+                      fill="currentColor"
+                      viewBox="0 0 20 20"
+                    >
+                      <path
+                        fill-rule="evenodd"
+                        d="M14.707 12.707a1 1 0 01-1.414 0L10 9.414l-3.293 3.293a1 1 0 01-1.414-1.414l4-4a1 1 0 011.414 0l4 4a1 1 0 010 1.414z"
+                        clip-rule="evenodd"
+                      />
+                    </svg>
+                  </button>
+                  <div class="mt-1 border-t border-gray-100 px-3 py-1 text-[10px] normal-case tracking-normal text-gray-400 dark:border-dark-700 dark:text-dark-500">
+                    {{ t('admin.users.sortCurrentPageOnly') }}
+                  </div>
+                </div>
               </div>
             </div>
           </template>
 
+          <template #cell-usage="{ row }">
+            <PlatformUsageBreakdown
+              :today="usageStats[row.id]?.today_actual_cost ?? 0"
+              :total="usageStats[row.id]?.total_actual_cost ?? 0"
+              :by-platform="usageStats[row.id]?.by_platform"
+            />
+          </template>
+
+          <template #cell-usage_anthropic="{ row }">
+            <PlatformCostCell :usage="getPlatformUsage(row.id, 'anthropic')" />
+          </template>
+
+          <template #cell-usage_openai="{ row }">
+            <PlatformCostCell :usage="getPlatformUsage(row.id, 'openai')" />
+          </template>
+
+          <template #cell-usage_gemini="{ row }">
+            <PlatformCostCell :usage="getPlatformUsage(row.id, 'gemini')" />
+          </template>
+
+          <template #cell-usage_antigravity="{ row }">
+            <PlatformCostCell :usage="getPlatformUsage(row.id, 'antigravity')" />
+          </template>
+
           <template #cell-concurrency="{ row }">
             <UserConcurrencyCell
               :current="row.current_concurrency ?? 0"
@@ -641,6 +734,8 @@ import GroupBadge from '@/components/common/GroupBadge.vue'
 import Select from '@/components/common/Select.vue'
 import UserAttributesConfigModal from '@/components/user/UserAttributesConfigModal.vue'
 import UserConcurrencyCell from '@/components/user/UserConcurrencyCell.vue'
+import PlatformUsageBreakdown from '@/components/user/PlatformUsageBreakdown.vue'
+import PlatformCostCell from '@/components/user/PlatformCostCell.vue'
 import UserCreateModal from '@/components/admin/user/UserCreateModal.vue'
 import UserEditModal from '@/components/admin/user/UserEditModal.vue'
 import UserApiKeysModal from '@/components/admin/user/UserApiKeysModal.vue'
@@ -710,6 +805,10 @@ const allColumns = computed<Column[]>(() => [
   { key: 'subscriptions', label: t('admin.users.columns.subscriptions'), sortable: false },
   { key: 'balance', label: t('admin.users.columns.balance'), sortable: true },
   { key: 'usage', label: t('admin.users.columns.usage'), sortable: false },
+  { key: 'usage_anthropic', label: t('admin.users.columns.usageAnthropic'), sortable: false },
+  { key: 'usage_openai', label: t('admin.users.columns.usageOpenAI'), sortable: false },
+  { key: 'usage_gemini', label: t('admin.users.columns.usageGemini'), sortable: false },
+  { key: 'usage_antigravity', label: t('admin.users.columns.usageAntigravity'), sortable: false },
   { key: 'concurrency', label: t('admin.users.columns.concurrency'), sortable: true },
   { key: 'status', label: t('admin.users.columns.status'), sortable: true },
   { key: 'last_active_at', label: t('admin.users.columns.lastActive'), sortable: true },
@@ -728,12 +827,25 @@ const toggleableColumns = computed(() =>
 const hiddenColumns = reactive<Set<string>>(new Set())
 
 // Default hidden columns (columns hidden by default on first load)
-const DEFAULT_HIDDEN_COLUMNS = ['notes', 'groups', 'subscriptions', 'usage', 'concurrency']
+const DEFAULT_HIDDEN_COLUMNS = [
+  'notes', 'groups', 'subscriptions', 'usage', 'concurrency',
+  'usage_anthropic', 'usage_openai', 'usage_gemini', 'usage_antigravity'
+]
 const REMOVED_COLUMNS = new Set(['last_login_at'])
-const FORCED_VISIBLE_COLUMNS = new Set(['last_active_at'])
+// 强制可见列：加载时会被强制移出 hiddenColumns，并在列设置 UI 上 disabled。
+// 当前没有列需要强制可见 —— last_active_at 已改为可被用户隐藏。
+const FORCED_VISIBLE_COLUMNS = new Set<string>()
 
-// localStorage key for column settings
+// localStorage keys for column settings
 const HIDDEN_COLUMNS_KEY = 'user-hidden-columns'
+// 列设置 schema 版本号。每次给 DEFAULT_HIDDEN_COLUMNS 新增列时 bump 一次，
+// 并在 VERSION_NEW_HIDDEN_COLUMNS 中登记该版本新增的 key。
+// 这样老用户升级后这些新列会被自动隐藏一次，而不会影响他们对其它老列的偏好。
+const COLUMN_SETTINGS_VERSION_KEY = 'user-column-settings-version'
+const COLUMN_SETTINGS_VERSION = 2
+const VERSION_NEW_HIDDEN_COLUMNS: Record<number, string[]> = {
+  2: ['usage_anthropic', 'usage_openai', 'usage_gemini', 'usage_antigravity']
+}
 
 // Load saved column settings
 const loadSavedColumns = () => {
@@ -744,9 +856,27 @@ const loadSavedColumns = () => {
       parsed
         .filter(key => !REMOVED_COLUMNS.has(key) && !FORCED_VISIBLE_COLUMNS.has(key))
         .forEach(key => hiddenColumns.add(key))
+
+      // 老用户升级：把每个未应用过的版本里新增的默认隐藏列自动追加到 hiddenColumns。
+      const storedVersion = Number(localStorage.getItem(COLUMN_SETTINGS_VERSION_KEY) ?? '1')
+      if (storedVersion < COLUMN_SETTINGS_VERSION) {
+        let mutated = false
+        for (let v = storedVersion + 1; v <= COLUMN_SETTINGS_VERSION; v++) {
+          for (const key of VERSION_NEW_HIDDEN_COLUMNS[v] ?? []) {
+            if (REMOVED_COLUMNS.has(key) || FORCED_VISIBLE_COLUMNS.has(key)) continue
+            if (!hiddenColumns.has(key)) {
+              hiddenColumns.add(key)
+              mutated = true
+            }
+          }
+        }
+        if (mutated) saveColumnsToStorage()
+        else localStorage.setItem(COLUMN_SETTINGS_VERSION_KEY, String(COLUMN_SETTINGS_VERSION))
+      }
     } else {
       // Use default hidden columns on first load
       DEFAULT_HIDDEN_COLUMNS.forEach(key => hiddenColumns.add(key))
+      localStorage.setItem(COLUMN_SETTINGS_VERSION_KEY, String(COLUMN_SETTINGS_VERSION))
     }
   } catch (e) {
     console.error('Failed to load saved columns:', e)
@@ -758,13 +888,18 @@ const loadSavedColumns = () => {
 const saveColumnsToStorage = () => {
   try {
     localStorage.setItem(HIDDEN_COLUMNS_KEY, JSON.stringify([...hiddenColumns]))
+    localStorage.setItem(COLUMN_SETTINGS_VERSION_KEY, String(COLUMN_SETTINGS_VERSION))
   } catch (e) {
     console.error('Failed to save columns:', e)
   }
 }
 
 // Toggle column visibility
+const isForcedVisibleColumn = (key: string) => FORCED_VISIBLE_COLUMNS.has(key)
 const toggleColumn = (key: string) => {
+  // 强制可见列(如 last_active_at)在加载时会被恢复成可见，
+  // 这里阻止用户在当前会话隐藏它，避免"取消勾选 → 刷新又恢复"的反直觉行为。
+  if (FORCED_VISIBLE_COLUMNS.has(key)) return
   const wasHidden = hiddenColumns.has(key)
   if (hiddenColumns.has(key)) {
     hiddenColumns.delete(key)
@@ -772,7 +907,7 @@ const toggleColumn = (key: string) => {
     hiddenColumns.add(key)
   }
   saveColumnsToStorage()
-  if (wasHidden && (key === 'usage' || key.startsWith('attr_'))) {
+  if (wasHidden && (key === 'usage' || key.startsWith('usage_') || key.startsWith('attr_'))) {
     refreshCurrentPageSecondaryData()
   }
   if (key === 'subscriptions') {
@@ -785,7 +920,22 @@ const toggleColumn = (key: string) => {
 
 // Check if column is visible (not in hidden set)
 const isColumnVisible = (key: string) => !hiddenColumns.has(key)
-const hasVisibleUsageColumn = computed(() => !hiddenColumns.has('usage'))
+// usage 主列或任意 usage_<platform> 子列可见时都需要批量拉取用量数据
+// 列 key → 平台名（'usage' 主列汇总所有平台时为 null）
+// 显式数组取代 Object.keys()：保证迭代顺序（决定列头排序按钮渲染顺序）
+// 不会因 JS 引擎差异或 USAGE_COLUMN_PLATFORMS 属性顺序调整而静默变化。
+const USAGE_COLUMN_KEYS: readonly string[] = ['usage', 'usage_anthropic', 'usage_openai', 'usage_gemini', 'usage_antigravity']
+const USAGE_COLUMN_PLATFORMS: Record<string, string | null> = {
+  usage: null,
+  usage_anthropic: 'anthropic',
+  usage_openai: 'openai',
+  usage_gemini: 'gemini',
+  usage_antigravity: 'antigravity'
+}
+const PLATFORM_USAGE_COLUMNS = USAGE_COLUMN_KEYS.filter((k) => k !== 'usage')
+const hasVisibleUsageColumn = computed(
+  () => !hiddenColumns.has('usage') || PLATFORM_USAGE_COLUMNS.some((k) => !hiddenColumns.has(k))
+)
 const hasVisibleSubscriptionsColumn = computed(() => !hiddenColumns.has('subscriptions'))
 const hasVisibleGroupsColumn = computed(() => !hiddenColumns.has('groups'))
 const hasVisibleAttributeColumns = computed(() =>
@@ -945,6 +1095,97 @@ const getAttributeDefinition = (attrId: number): UserAttributeDefinition | undef
   return attributeDefinitions.value.find(d => d.id === attrId)
 }
 const usageStats = ref<Record<string, BatchUserUsageStats>>({})
+
+const getPlatformUsage = (userId: number, platform: string) =>
+  usageStats.value[userId]?.by_platform?.find((p) => p.platform === platform)
+
+// 用量列前端排序：DataTable 工作在 server-side-sort 模式，所有 sortable
+// 字段都会触发后端查询，而用量列数据是异步批量拉取后再合并到当前页，
+// 因此采用独立的前端排序状态对当前页 users 做本地排序。
+// 排序状态独立于后端 sortState 持久化；缺失数据按 0 处理（desc 沉底、asc 置顶）。
+type UsageMetric = 'today' | 'total'
+type UsageSortState = { key: string; metric: UsageMetric; order: 'asc' | 'desc' } | null
+const USAGE_SORT_STORAGE_KEY = 'admin-users-usage-sort'
+
+const loadInitialUsageSort = (): UsageSortState => {
+  try {
+    const raw = localStorage.getItem(USAGE_SORT_STORAGE_KEY)
+    if (!raw) return null
+    const parsed = JSON.parse(raw) as Partial<{ key: string; metric: string; order: string }>
+    if (!parsed.key || !USAGE_COLUMN_KEYS.includes(parsed.key)) return null
+    const metric: UsageMetric = parsed.metric === 'total' ? 'total' : 'today'
+    const order: 'asc' | 'desc' = parsed.order === 'asc' ? 'asc' : 'desc'
+    return { key: parsed.key, metric, order }
+  } catch {
+    return null
+  }
+}
+const usageSort = ref<UsageSortState>(loadInitialUsageSort())
+const persistUsageSort = () => {
+  try {
+    if (usageSort.value) {
+      localStorage.setItem(USAGE_SORT_STORAGE_KEY, JSON.stringify(usageSort.value))
+    } else {
+      localStorage.removeItem(USAGE_SORT_STORAGE_KEY)
+    }
+  } catch (e) {
+    console.error('Failed to persist usage sort:', e)
+  }
+}
+
+const isUsageSortActive = (key: string, metric: UsageMetric) =>
+  !!usageSort.value && usageSort.value.key === key && usageSort.value.metric === metric
+const getUsageSortOrder = (key: string, metric: UsageMetric): 'asc' | 'desc' | null =>
+  isUsageSortActive(key, metric) ? usageSort.value!.order : null
+
+// 三态循环：desc → asc → off。选完即关闭菜单（用户大多希望"选中即应用"，
+// 想再切换 order 时重新打开菜单点同一项即可）。
+const toggleUsageSort = (key: string, metric: UsageMetric) => {
+  const cur = usageSort.value
+  if (cur && cur.key === key && cur.metric === metric) {
+    usageSort.value = cur.order === 'desc' ? { key, metric, order: 'asc' } : null
+  } else {
+    usageSort.value = { key, metric, order: 'desc' }
+  }
+  persistUsageSort()
+  openUsageSortMenu.value = null
+}
+
+// 列头排序按钮点击后弹出的"今日/近30天"选择菜单，同时只允许一个列展开。
+// 点击图标本身不触发排序，仅开关菜单；首次排序由用户在菜单内选择 metric 触发（默认 desc，详见 toggleUsageSort）。
+const openUsageSortMenu = ref<string | null>(null)
+const toggleUsageSortMenu = (key: string) => {
+  openUsageSortMenu.value = openUsageSortMenu.value === key ? null : key
+}
+
+const getUsageValue = (userId: number, key: string, metric: UsageMetric): number => {
+  const stats = usageStats.value[userId]
+  if (!stats) return 0
+  const platform = USAGE_COLUMN_PLATFORMS[key]
+  if (platform === null) {
+    return metric === 'today' ? stats.today_actual_cost ?? 0 : stats.total_actual_cost ?? 0
+  }
+  const p = stats.by_platform?.find((x) => x.platform === platform)
+  if (!p) return 0
+  return metric === 'today' ? p.today_actual_cost ?? 0 : p.total_actual_cost ?? 0
+}
+
+// 在 server-side 排序结果之上叠加用量列的本地排序；无 usageSort 时直接透传原数组。
+// 稳定排序：等值按原 index 保序，避免拉取新用量数据时表行抖动。
+const sortedUsers = computed(() => {
+  const s = usageSort.value
+  if (!s) return users.value
+  return [...users.value]
+    .map((row, index) => ({ row, index }))
+    .sort((a, b) => {
+      const av = getUsageValue(a.row.id, s.key, s.metric)
+      const bv = getUsageValue(b.row.id, s.key, s.metric)
+      if (av !== bv) return s.order === 'asc' ? av - bv : bv - av
+      return a.index - b.index
+    })
+    .map((x) => x.row)
+})
+
 // User attribute definitions and values
 const attributeDefinitions = ref<UserAttributeDefinition[]>([])
 const userAttributeValues = ref<Record<number, Record<number, string>>>({})
@@ -1095,6 +1336,10 @@ const handleClickOutside = (event: MouseEvent) => {
   if (columnDropdownRef.value && !columnDropdownRef.value.contains(target)) {
     showColumnDropdown.value = false
   }
+  // Close usage sort dropdown when clicking outside any usage-sort-trigger
+  if (openUsageSortMenu.value !== null && !target.closest('.usage-sort-trigger')) {
+    openUsageSortMenu.value = null
+  }
   // Close expanded group dropdown when clicking outside
   if (expandedGroupUserId.value !== null) {
     expandedGroupUserId.value = null