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                <!-- EDITING -->
<label for="range">Optical Size</label>
<input id="range" type="range" name="SPAC" min="10" max="72" value="50">

<!-- ARTICLE -->
    <p>Amstelvar is a typeface inspired by the typeface designs used in The Netherlands and Belgium from the sixteenth century to the development of Times Roman in the 1930s.</p>
    <p>It is the first public demonstration of the Type Network "Parametric Axes" approach to the OpenType Variable Fonts technology. Read more about this axis system at</p>
    <p>The font is licensed under the SIL Open Font License, which permits unrestricted usage, distribution, and modification, subject to terms in the license.</p>


                :root {
  --opsz: 50;

label {
  display: inline-block;
  font-family: monospace;
  text-transform: uppercase;
  line-height: 1;
  vertical-align: middle;
  font-weight: bold;

input {
  display: inline-block;
  margin: 0 0 0 0.5em;
  vertical-align: middle;

article {
  max-width: 75ex;
  margin: 2em 0 0 0;
  font-family: 'Amstelvar', serif;
    'wght' 400,
    'wdth' 100,
    'opsz' calc(72 - var(--opsz) + 10),
    'XOPQ' 88,
    'XTRA' 402,
    'YOPQ' 50,
    'YTLC' 500,
    'YTSE' 18,
    'GRAD' 88,
    'XTCH' 1000,
    'YTCH' 1000,
    'YTAS' 750,
    'YTDE' 250,
    'YTUC' 750,
    'YTRA' 1000,
    'PWGT' 88,
    'PWDT' 402;

p {
  line-height: 1.5;

@font-face {
	src: url('');
	font-style: normal;


                function increase(event) {'--opsz',;
		document.getElementById('range').addEventListener('input', increase);