If all else fails, go full superhero mode. Convert your layer to a Smart Object (right-click the layer > Convert to Smart Object). Then go to Filter > Camera Raw Filter.
In the panel that opens, click the Detail tab (the triangle icon). Crank Amount to 50–80, Radius to 1.0, Detail to 25, and Masking to 80.
Hold the Alt key while dragging the Masking slider—you’ll see the black areas stay untouched. That’s pure Photoshop sorcery right there.
One More Thing: Don’t Overdo It
I know it’s tempting to crank every slider to max. Please don’t. That’s how we get Uncanny Valley photos—sharp enough to cut glass, but weirdly unnatural.
Sharpening is like hot sauce: a little goes a long way. Add too much and you ruin the whole dish.
Zoom in and out as you work. If you see white halos around edges, dial it back. Your photo should look clear, not aggressive.