Fix 5 Performance issues in res\css\app.css

[pushkar-anand]

CodeFactor found multiple issues:

The universal selector (*) is known to be slow.

res\css\app.css:10

Element (ul#tool) is overqualified, just use #tool without element name.

res\css\app.css:23

Element (div#search) is overqualified, just use #search without element name.

res\css\app.css:56

Element (input#search-input) is overqualified, just use #search-input without element name.

res\css\app.css:61

@import prevents parallel downloads, use instead.

res\css\app.css:1