feat: add cached and reasoning token metrics with internationalization support

styles.css

@@ -2988,11 +2988,23 @@ input:checked+.slider:before {
 /* 使用统计样式 */
 .stats-overview {
     display: grid;
-    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
+    grid-template-columns: repeat(3, minmax(0, 1fr));
     gap: 20px;
     margin-bottom: 30px;
 }
 
+@media (max-width: 1200px) {
+    .stats-overview {
+        grid-template-columns: repeat(2, minmax(0, 1fr));
+    }
+}
+
+@media (max-width: 768px) {
+    .stats-overview {
+        grid-template-columns: 1fr;
+    }
+}
+
 .usage-filter-bar {
     display: flex;
     justify-content: flex-start;
@@ -3086,6 +3098,16 @@ input:checked+.slider:before {
     font-weight: 500;
 }
 
+.stat-subtext {
+    font-size: 12px;
+    color: var(--text-tertiary);
+    line-height: 1.4;
+}
+
+.stat-subtext:first-of-type {
+    margin-top: 6px;
+}
+
 .charts-container {
     display: grid;
     grid-template-columns: 1fr 1fr;