Custom CSS Not Working

Hi

Please check on screenshot – https://www.screencast.com/t/3h1DNqgj

It was Possible on “PDF image” and “Download PDF Text” display on single line.

I am try on add custom css but it was not working. – https://www.screencast.com/t/EBTXbtIBaUP

.amp-wp-enforced-sizes .i-amphtml-element .i-amphtml-layout-responsive .i-amphtml-layout-size-defined .i-amphtml-layout{
float:left;
}

Site url is – https://test8.guru99.com/top-35-seo-interview-questions/amp/

Please help me.