修复行情页品种下拉列表被遮挡的问题

展开下拉时取消卡片 overflow 裁切，并提高下拉与工具栏层级。

Co-authored-by: Cursor <cursoragent@cursor.com>

templates/base.html

@@ -280,14 +280,16 @@
         }
         .stat-item .label{font-size:.8rem;color:var(--text-muted)}
         .stat-item .value{font-size:1.4rem;font-weight:600;color:var(--text-title);margin-top:.25rem}
-        .symbol-wrap{position:relative}
+        .symbol-wrap{position:relative;z-index:1}
+        .symbol-wrap:has(.symbol-dropdown.show){z-index:50}
         .symbol-dropdown{
             position:absolute;top:100%;left:0;right:0;
             background:var(--input-bg);border:1px solid var(--input-border);
-            border-radius:10px;margin-top:4px;z-index:100;
+            border-radius:10px;margin-top:4px;z-index:200;
             max-height:240px;overflow-y:auto;display:none;
-            box-shadow:var(--shadow-card);
+            box-shadow:var(--shadow-card-hover);
         }
+        .card:has(.symbol-dropdown.show){overflow:visible}
         .symbol-dropdown.show{display:block}
         .symbol-option{padding:.65rem 1rem;cursor:pointer;font-size:.85rem;border-bottom:1px solid var(--table-border)}
         .symbol-option:hover{background:var(--list-item-bg)}

templates/market.html

@@ -34,9 +34,13 @@
 </div>
 
 <style>
+.market-card{overflow:visible}
 .market-card h2{margin-bottom:.75rem}
-.market-toolbar{display:flex;flex-wrap:wrap;gap:.65rem;align-items:flex-end;margin-bottom:.75rem}
+.market-toolbar{
-.market-symbol-wrap{flex:1;min-width:200px;max-width:360px}
+    display:flex;flex-wrap:wrap;gap:.65rem;align-items:flex-end;
+    margin-bottom:.75rem;position:relative;z-index:2;
+}
+.market-symbol-wrap{flex:1;min-width:200px;max-width:360px;z-index:3}
 .market-period-tabs{display:flex;flex-wrap:wrap;gap:.35rem;align-items:center}
 .period-tab{
     padding:.4rem .65rem;border-radius:999px;