diff --git a/main.go b/main.go
index 602ce8c..0b7da5f 100644
--- a/main.go
+++ b/main.go
@@ -26,6 +26,7 @@ type Task struct {
     LastCheck   time.Time `json:"last_check"`
     Status      string    `json:"status"`
     Notified    bool      `json:"notified"` 
+    History     []HistoryItem `json:"history"`
 }
 
 type Config struct {
@@ -36,6 +37,11 @@ type Config struct {
     NotifyEnabled  bool   `json:"notify_enabled"` 
 }
 
+type HistoryItem struct {
+    State string    `json:"state"`
+    Time  time.Time `json:"time"`
+}
+
 var (
     tasks      = make(map[string]*Task)
     config     = &Config{Interval: 60, Timeout: 20, NotifyEnabled: true}
@@ -248,46 +254,24 @@ func handleIndex(w http.ResponseWriter, r *http.Request) {
         const token = localStorage.getItem('token') || prompt('请输入访问令牌:');
         if(token) localStorage.setItem('token', token);
         const headers = {'Authorization': 'Bearer ' + token};
-        let historyData = {};
-        const MAX_BARS = 90;
 
-        function initHistory(id) {
-            if(!historyData[id]) {
-                historyData[id] = Array(MAX_BARS).fill({state: 'unknown', time: null});
-            }
-        }
-
-        function updateHistory(id, state, time) {
-            initHistory(id);
-            historyData[id].shift();
-            historyData[id].push({state, time});
-        }
 
         function loadTasks() {
             fetch('/api/tasks', {headers})
                 .then(r => r.json())
                 .then(tasks => {
-                    tasks.forEach(t => {
-                        initHistory(t.id);
-                        const state = t.status === 'ok' ? (t.in_stock ? 'stock' : 'no-stock') : (t.status === 'error' ? 'error' : 'unknown');
-                        const lastState = historyData[t.id][MAX_BARS - 1];
-                        if(!lastState.time || lastState.time !== t.last_check) {
-                            updateHistory(t.id, state, t.last_check || Date.now());
-                        }
-                    });
-
                     const tbody = document.querySelector('#taskTable tbody');
                     tbody.innerHTML = tasks.map(t => {
                         const statusClass = t.status || 'checking';
                         const stockText = t.in_stock ? '<span class="stock-yes">有货</span>' : '<span class="stock-no">无货</span>';
                         const lastCheck = t.last_check ? new Date(t.last_check).toLocaleString('zh-CN') : '-';
-                        const history = historyData[t.id] || [];
+                        
+                        const history = t.history || [];
                         const uptimeBar = history.map(h => {
-                            const time = h.time ? new Date(h.time).toLocaleString('zh-CN') : '等待检测';
+                            const time = new Date(h.time).toLocaleString('zh-CN');
                             const label = h.state === 'stock' ? '有货' : h.state === 'no-stock' ? '无货' : h.state === 'error' ? '错误' : '未知';
                             return '<div class="uptime-item ' + h.state + '"><span class="uptime-tooltip">' + time + '<br>' + label + '</span></div>';
                         }).join('');
-
                         return '<tr>' +
                             '<td class="status-cell"><span class="status ' + statusClass + '"></span></td>' +
                             '<td>' + t.name + '</td>' +
@@ -359,7 +343,6 @@ func handleIndex(w http.ResponseWriter, r *http.Request) {
             if(!confirm('确认删除?')) return;
             fetch('/api/task?id=' + id, {method: 'DELETE', headers})
                 .then(() => {
-                    delete historyData[id];
                     loadTasks();
                 });
         }
@@ -490,8 +473,6 @@ func checker(ctx context.Context) {
 }
 
 func checkTask(task *Task) {
-    task.Status = "checking"
-    
     body, err := fetch(task.URL)
     now := time.Now()
     
@@ -504,6 +485,16 @@ func checkTask(task *Task) {
         inStock = !strings.Contains(body, task.OutOfStock)
     }
     
+    state := "unknown"
+    if status == "ok" {
+        state = "no-stock"
+        if inStock {
+            state = "stock"
+        }
+    } else if status == "error" {
+        state = "error"
+    }
+    
     mu.Lock()
     wasInStock := task.InStock
     wasNotified := task.Notified
@@ -511,11 +502,19 @@ func checkTask(task *Task) {
     task.InStock = inStock
     task.LastCheck = now
     
+    if task.History == nil {
+        task.History = []HistoryItem{}
+    }
+    task.History = append(task.History, HistoryItem{State: state, Time: now})
+    if len(task.History) > 90 {
+        task.History = task.History[len(task.History)-90:]
+    }
+    
     if !inStock {
         task.Notified = false
     }
     mu.Unlock()
-    saveTasks() 
+    saveTasks()
     
     configMu.RLock()
     notifyEnabled := config.NotifyEnabled