See lesscss.org for full documentation on Less CSS capabilities and syntax.
Typical use will be something like:
var less = require('less').compile;
var source = [
'@base: #f938ab;',
'',
'.box-shadow(@style, @c) when (iscolor(@c)) {',
' box-shadow: @style @c;',
' -webkit-box-shadow: @style @c;',
' -moz-box-shadow: @style @c;',
'}',
'.box-shadow(@style, @alpha: 50%) when (isnumber(@alpha)) {',
'.box-shadow(@style, rgba(0, 0, 0, @alpha));',
'}',
'.box {',
' color: saturate(@base, 5%);',
' border-color: lighten(@base, 30%);',
' div { .box-shadow(0 0 5px, 30%) }',
'}'
].join('\n');
console.log(less(source));