style(` body background #ccc div width 100px height 100px background white box-shadow 0 1px 2px rgba(0, 0, 0, .5) transform translateX(50%) scale(.5) `)
jscss takes approximately
0.03s to parse and insert 10,000 lines of CSS (Firefox 35, OS X
10.10). Good enough. And it's just 20 lines (uncompressed), so the loading should be acceptable too.
Any ES2015-friendly browser (which basically means Firefox 35 at the time of writing).