feat: 固定system message页面内容高度

src/views/SystemMessage/src/SystemMessage.vue

@@ -157,7 +157,7 @@ const notificationList = [
 }
 .system-message {
   display: flex;
-  height: calc(100% - 72px);
+  height: calc(100% - 68px);
 }
 .left-nav {
   width: 280px;
@@ -231,6 +231,7 @@ const notificationList = [
 .right-content {
   flex: 1;
   padding-top: 24px;
+  overflow-y: auto;
   :deep(.el-tabs__nav-scroll) {
     padding-left: 16px;
     border-bottom: 1px solid var(--color-border);