Go visit that "app" and use the arrow keys and mouse clicks, and form a coherent theory of how the arrow keys do something sensible. arrow down moves a highligh

Go visit that "app" and use the arrow keys and mouse clicks, and form a coherent theory of how the arrow keys do something sensible. arrow down moves a highlight cursor down the page, until you click, at which point highlighting disappears, and arrow starts scrolling the page, or does nothing, depending on...something?