fix: card title style to gray

app/containers/DataManagerOverview/index.less

@@ -62,6 +62,7 @@
       background-size: cover;
       border-radius: 6px;
       transition: all .2s ease;
+      color: rgba(255, 255, 255, .6);
 
       &:hover {
         box-shadow: 0 3px 8px -3px rgba(0, 0, 0, 0.1);
@@ -72,16 +73,15 @@
       }
 
       .title {
-        font-size: 18px;
+        font-size: 16px;
         padding-bottom: 10px;
-        color: rgba(0, 0, 0, .4);
       }
 
       .num {
         font-size: 30px;
-        font-weight: bold;
         color: #fff;
         padding-right: 8px;
+        font-family: 'Arial';
       }
 
       img {