*{box-sizing:border-box}
body{
  max-width:40em;margin:0 auto;padding:20px;
  background:#fff;color:#000;
  font-family:"MS Gothic","MS Mincho",monospace;
  line-height:1.8
}
h1,h2{font-weight:normal}
h1{margin:0;font-size:1.2em}
h2{margin:0 0 .25em;font-size:1em}
canvas{
  display:block;width:100%;aspect-ratio:1/1;
  margin:1em 0 1.5em;border:1px solid #000;background:#fff;
  cursor:crosshair;
  touch-action:none
}
section{margin:1.5em 0}
output{display:block;font-size:.9em}
.buttons{display:flex;gap:.5em;flex-wrap:wrap}
button{
  font:inherit;padding:.15em .6em;border:1px solid #000;
  border-radius:0;background:#fff;color:#000;cursor:pointer
}
button:hover{background:#000;color:#fff}
button:focus-visible{outline:1px solid #000;outline-offset:3px}