Test
You should see a grid with perfectly straight black lines. If not, please consider installing some MathML fonts.
Test grid
<div style="width: 540px; height: 540px; background: #eef;">
<div style="position: absolute;">
<div style="position: absolute; left: 20px; top: 20px;">
<div style="position: absolute;">
<div style="position: absolute; top: 0; left: 0;">
<math><mo minsize="500px">√</mo></math></div>
<div style="position: absolute; top: 0; left: 30px;">
<math><mo minsize="500px">√</mo></math></div>
<div style="position: absolute; top: 0; left: 60px;">
<math><mo minsize="500px">√</mo></math></div>
<div style="position: absolute; top: 0; left: 90px;">
<math><mo minsize="500px">√</mo></math></div>
<div style="position: absolute; top: 0; left: 120px;">
<math><mo minsize="500px">√</mo></math></div>
<div style="position: absolute; top: 0; left: 150px;">
<math><mo minsize="500px">√</mo></math></div>
<div style="position: absolute; top: 0; left: 180px;">
<math><mo minsize="500px">√</mo></math></div>
<div style="position: absolute; top: 0; left: 210px;">
<math><mo minsize="500px">√</mo></math></div>
<div style="position: absolute; top: 0; left: 240px;">
<math><mo minsize="500px">√</mo></math></div>
<div style="position: absolute; top: 0; left: 270px;">
<math><mo minsize="500px">√</mo></math></div>
<div style="position: absolute; top: 0; left: 300px;">
<math><mo minsize="500px">√</mo></math></div>
<div style="position: absolute; top: 0; left: 330px;">
<math><mo minsize="500px">√</mo></math></div>
<div style="position: absolute; top: 0; left: 360px;">
<math><mo minsize="500px">√</mo></math></div>
<div style="position: absolute; top: 0; left: 390px;">
<math><mo minsize="500px">√</mo></math></div>
<div style="position: absolute; top: 0; left: 420px;">
<math><mo minsize="500px">√</mo></math></div>
<div style="position: absolute; top: 0; left: 450px;">
<math><mo minsize="500px">√</mo></math></div>
</div>
<div style="position: absolute;">
<div style="position: absolute; top: 0; left: 0;">
<math> <mover><mo>⏜</mo><mspace width="500px"></mspace></mover> </math></div>
<div style="position: absolute; top: 30px; left: 0;">
<math> <mover><mo>⏜</mo><mspace width="500px"></mspace></mover> </math></div>
<div style="position: absolute; top: 60px; left: 0;">
<math> <mover><mo>⏜</mo><mspace width="500px"></mspace></mover> </math></div>
<div style="position: absolute; top: 90px; left: 0;">
<math> <mover><mo>⏜</mo><mspace width="500px"></mspace></mover> </math></div>
<div style="position: absolute; top: 120px; left: 0;">
<math> <mover><mo>⏜</mo><mspace width="500px"></mspace></mover> </math></div>
<div style="position: absolute; top: 150px; left: 0;">
<math> <mover><mo>⏜</mo><mspace width="500px"></mspace></mover> </math></div>
<div style="position: absolute; top: 180px; left: 0;">
<math> <mover><mo>⏜</mo><mspace width="500px"></mspace></mover> </math></div>
<div style="position: absolute; top: 210px; left: 0;">
<math> <mover><mo>⏜</mo><mspace width="500px"></mspace></mover> </math></div>
<div style="position: absolute; top: 240px; left: 0;">
<math> <mover><mo>⏜</mo><mspace width="500px"></mspace></mover> </math></div>
<div style="position: absolute; top: 270px; left: 0;">
<math> <mover><mo>⏜</mo><mspace width="500px"></mspace></mover> </math></div>
<div style="position: absolute; top: 300px; left: 0;">
<math> <mover><mo>⏜</mo><mspace width="500px"></mspace></mover> </math></div>
<div style="position: absolute; top: 330px; left: 0;">
<math> <mover><mo>⏜</mo><mspace width="500px"></mspace></mover> </math></div>
<div style="position: absolute; top: 360px; left: 0;">
<math> <mover><mo>⏜</mo><mspace width="500px"></mspace></mover> </math></div>
<div style="position: absolute; top: 390px; left: 0;">
<math> <mover><mo>⏜</mo><mspace width="500px"></mspace></mover> </math></div>
<div style="position: absolute; top: 420px; left: 0;">
<math> <mover><mo>⏜</mo><mspace width="500px"></mspace></mover> </math></div>
<div style="position: absolute; top: 450px; left: 0;">
<math> <mover><mo>⏜</mo><mspace width="500px"></mspace></mover> </math></div>
</div>
<div style="position: absolute;">
<div style="position: absolute; background: #eef; top: -20px; height: 40px; width: 500px;">
</div>
<div style="position: absolute; background: #eef; top: 480px; height: 40px; width: 500px;">
</div>
</div>
<div style="position: absolute;">
<div style="position: absolute; background: #eef; left: -20px; width: 40px; height: 500px;">
</div>
<div style="position: absolute; background: #eef; left: 480px; width: 40px; height: 500px;">
</div>
</div>
</div>
</div>
</div>