body{font-family:Arial,Helvetica,sans-serif;max-width:800px;margin:0 auto;padding:0 1em}label{display:block;margin-top:1em}label>input{margin-left:1em}.grid{margin-top:1em;display:grid;grid-template-rows:100%;grid-template-columns:50% 50%}.grid video{width:100%;margin:auto 0}.grid canvas{margin:auto;max-width:100%}canvas{padding:0}.intro{padding:1rem}h1{font-size:1.8rem;margin-bottom:.5rem}