Coding

<style>

html, body {margin: 0; height: 100%; overflow: hidden}

* {text-align: center;}

body::-webkit-scrollbar {display: block;}

body::-webkit-scrollbar-track {display: block;}

body::-webkit-scrollbar-thumb {display: block;}

</style>

&rm=minimal

For the second one you put it after the 'delayms=NUMBER'

So all together it is 'delayms=NUMBER&rm=minimal"'

For all of these you will need to add

<style>

* {text-align: center;}

<style>