style: 样式修改

src/views/attend-class/index.module.less

@@ -648,7 +648,7 @@
     justify-content: center;
     z-index: 9;
     &.active, &:hover {
-      background: rgba(0, 0, 0, 0.16);
+      background: RGBA(255, 255, 255, 0.3);
       border-radius: 8px;
       z-index: 9;
     }