Multiple text-shadows..
Something like this:
var steps = 10, i, R = 0.6, x, y, theStyle = '1vw 1vw 3vw #005dab';for (i = -steps; i <= steps; i += 1) { x = (i / steps) / 2; y = Math.sqrt(Math.pow(R, 2) - Math.pow(x, 2)); theStyle = theStyle +','+ x.toString() +'vw '+ y.toString() +'vw 0 #005dab'; theStyle = theStyle +','+ x.toString() +'vw -'+ y.toString() +'vw 0 #005dab'; theStyle = theStyle +','+ y.toString() +'vw '+ x.toString() +'vw 0 #005dab'; theStyle = theStyle +',-'+ y.toString() +'vw '+ x.toString() +'vw 0 #005dab';}document.getElementsByTagName("H1")[0].setAttribute("style", "text-shadow:"+ theStyle);