feat: 优化商品洞察相关代码逻辑、新增性能优化 SQL 并更新前端样式

dashboard-ui/styles.css

@@ -36,7 +36,7 @@
     margin: 0;
     padding: 0;
     box-sizing: border-box;
-    font-family: -apple-system, BlinkMacSystemFont, "Inter", "Helvetica Neue", sans-serif;
+    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
     -webkit-font-smoothing: antialiased;
 }
 
@@ -302,6 +302,52 @@ body {
     box-shadow: 0 12px 40px rgba(0, 0, 0, 0.08);
 }
 
+/* Chart header with optional controls */
+.chart-header {
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    flex-wrap: wrap;
+    gap: 12px;
+    margin-bottom: 1rem;
+}
+
+.chart-header h2 {
+    margin: 0;
+}
+
+/* Apple-style Segmented Control */
+.segment-control {
+    display: inline-flex;
+    background: rgba(134, 134, 139, 0.08);
+    border-radius: 10px;
+    padding: 3px;
+    gap: 2px;
+}
+
+.segment-btn {
+    padding: 5px 16px;
+    border: none;
+    border-radius: 8px;
+    background: transparent;
+    color: var(--text-secondary);
+    font-size: 0.8rem;
+    font-weight: 500;
+    cursor: pointer;
+    transition: all 0.25s ease;
+    font-family: inherit;
+}
+
+.segment-btn:hover {
+    color: var(--text-primary);
+}
+
+.segment-btn.active {
+    background: var(--text-primary);
+    color: var(--bg-base);
+    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.12);
+}
+
 /* Dashboard Grid */
 .dashboard-grid {
     display: flex;