style.css

body {
  margin: 0;
  font-family: Roboto, sans-serif;
}
header, main, footer {
  max-width: 800px;
  padding: 1em;
  margin: auto;
}
nav {
  text-align: right;
}
h1,h2,h3,strong,b {
  font-weight: 500;
}
hr {
  height: 3px;
  background-color: #e8e8e8;
  border: none;
  outline: none;
  margin: 3em;
}
#results, #exported-wrapper {
  display: none;
}
#results.done, #exported-wrapper.open {
  display: block;
}
#before, #after {
  padding: 1em;
  max-width: 100%;
  overflow-x: auto;
  text-align: center;
  background: linear-gradient(150deg, #70b4a9, #6fbab9, #6ea6c8, #6f78d9, #ae73e9, #f579f1, #fd7ec7, #ff81b6);
}
#before img, #after canvas {
  filter: drop-shadow(2px 4px 6px #444);
}
#before img {
  max-width: 50%;
  vertical-align: middle;
}
#after canvas {
  max-width: 100%;
  vertical-align: middle;
}
#controls {
  margin-bottom: 1em;
}
#size-input {
  vertical-align: middle;
}
#output-wrapper {
  max-width: 100%;
  max-height: 70vh;
  text-align: center;
  overflow: auto;
}
footer .timestamp {
  text-align: right;
  color: #aaa;
  font-size: 85%;
}
a[href] {
  text-decoration: none;
}
a[href]:focus, a[href]:hover, a[href]:active, a[href]:focus-within {
  text-decoration: underline;
}