add 预警

src/views/index.vue

@@ -512,8 +512,7 @@
 
   .el-card {
     text-align: center;
-    margin-right: 50px;
-    margin-bottom: 50px;
+    margin: 20px;
     background-image: url("../assets/knowledge/预警数量.png");
     background-repeat: no-repeat;
     background-size: 100% 100%;