1.CSS-4
<h2 id="css4"></h2>
<style>#css4::before{content:"1.CSS-4";}</style>
2.ATTR-4
<h2 data-title="2.ATTR-4" id="attr4"></h2>
<style>#attr4::before{content:attr(data-title);}</style>
3.IMG-4
<h2><img src="path/to/title4.png" alt=""></h2>
4.B64-4
// PHP GD ⇒ base64 image (see code sample)
5.SVGEM-4
<object data="title4.svg" type="image/svg+xml"></object>
6.CAN-4
<canvas id="can4" width="400" height="60"></canvas>
<script>
const c=document.getElementById('can4').getContext('2d');
c.font='32px Arial';c.fillText('6.CAN-4',10,40);
</script>
7.WEBGL-4
//
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