On this page, we used the bootstrap 4 CSS framework with some basic CSS properties. With the help of bootstrap 4 utility classes and grid systems we made a simple bootstrap error page.
Here we used one grid col-MD-12 class and display flex properties for layouts, but make the centre perfectly we used justify-content centre class and aliment item class of bootstrap. For make more attractive here used google fonts and nice colour combinations we used. This is fully responsive and mobile-friendly user-interface.
Make it yours now by using it, downloading it, and please share it. we will design more elements for you.