Unicode gives you a second alphabet that looks like a font but survives copy and paste. Bold, italic, monospace and small caps are the four workhorses, and they are all just different code points.
The fastest way to audition them is a browser converter. I keep Font Style Generator open when I need a heading that reads as bold inside an app that ignores formatting.
Remember that screen readers still read the underlying letters, so use styled text for decoration, not for the whole paragraph.
Written by FontStyle - more at fontstyle.io.