NEZ-3251 fix：explore 背景色显示错误

nezha-fronted/src/assets/css/components/page/dashboard/explore/explore.scss

@@ -168,6 +168,7 @@
   .main-container {
     padding: 0 !important;
     overflow: auto;
+    background-color: $--background-color-empty !important;
   }
   .metric-table {
     border-bottom: 1px solid $--border-color-light !important;

nezha-fronted/src/components/page/dashboard/explore/exploreItem.vue

@@ -1,6 +1,6 @@
 <template>
   <div class="explore list-page" :class="'nz-explore-' + tabIndex" style="position:relative;">
-    <div class="right-box__container main-list">
+    <div class="right-box__container main-list" style="padding: 0;">
       <div class="main-container explore-split-box" ref="exploreScrollbar" @mouseenter="tableHover = true" @mouseleave="tableHover = false">
         <!-- 关闭按钮 -->
         <div v-if="closable" class="explore-close">