diff --git a/index.html b/index.html
index fdc2472..554217e 100644
--- a/index.html
+++ b/index.html
@@ -156,6 +156,10 @@
                         <option value="30">近 30 天</option>
                     </select>
                 </div>
+                <div class="control-group">
+                    <label>按天</label>
+                    <select id="perfDay"><option value="all">全部日期</option></select>
+                </div>
             </div>
 
             <!-- 模块1：核心指标概览 -->
@@ -359,7 +363,8 @@
         fillSelect('perfChannel', [...new Set(perfData.map(d => d.channel))].sort());
         fillSelect('perfProduct', [...new Set(perfData.map(d => d.product))].sort());
         fillSelect('perfCountry', [...new Set(perfData.map(d => d.location))].filter(x=>x&&x!=='0').sort());
-        ['perfChannel','perfProduct','perfCountry','perfRange'].forEach(id =>
+        fillSelect('perfDay', [...new Set(perfData.map(d => d.date))].sort().reverse());
+        ['perfChannel','perfProduct','perfCountry','perfRange','perfDay'].forEach(id =>
             document.getElementById(id).addEventListener('change', drawPerf));
         drawPerf();
     }
@@ -370,10 +375,14 @@
         const pr = document.getElementById('perfProduct').value;
         const co = document.getElementById('perfCountry').value;
         const rg = document.getElementById('perfRange').value;
+        const day = document.getElementById('perfDay').value;
         if (ch !== 'all') d = d.filter(x => x.channel === ch);
         if (pr !== 'all') d = d.filter(x => x.product === pr);
         if (co !== 'all') d = d.filter(x => x.location === co);
-        if (rg !== 'all') {
+        // 选了具体某天则优先按天过滤（覆盖时间范围）；否则用时间范围
+        if (day !== 'all') {
+            d = d.filter(x => x.date === day);
+        } else if (rg !== 'all') {
             const allDates = [...new Set(perfData.map(x => x.date))].sort();
             const cut = allDates[Math.max(0, allDates.length - parseInt(rg))];
             d = d.filter(x => x.date >= cut);