Using math in calc on Less.js 2.7.3

https://stackoverflow.com/a/55168887/3840840

by Sebastian Brosch

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/less.js/2.7.3/less.min.js"></script>
<p class="test">Hello World</p>

CSS

@test: -0.05em;

.test {
  border: 1px solid red;
  padding-top: calc(-@test + 1em);
}

/**

Less.js (version 2.7.3). The above code compiles to the following CSS:

.test {
    border: 1px solid red;
    padding-top: calc(1.05em);
}

*/

JavaScript

/** https://stackoverflow.com/a/30699015/3840840 */
$('head style[type="text/css"]').attr('type','text/less');
less.env = 'development';
less.refreshStyles();