You're modifying the styling of an existing and often used class (.row), so then you have too many borders in your app. Instead, create an extra class, e.g. "bordered", to draw a border and add that class to the row / layoutgrid / whatever you want to draw the border around:
.bordered {
border: 1px solid #000;
}
Hello Jayasree,
You can do this by adding styling to your application.
A create start to explore this are the learning paths:
https://academy.mendix.com/link/paths/123/Style-your-App-with-Sass
also look at the documentation:
https://docs.mendix.com/howto/front-end/customize-styling-new/
and finally look at external sources for adding borders:
https://www.w3schools.com/css/css_border.asp
hope this helps,
Good luck!