html, body {
  margin: 0;
  height: 100%;
}

/* isolation: the img's multiply blend must resolve against this background */
main {
  min-height: 100%;
  background: #faf8f4;
  isolation: isolate;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* multiply: white paper disappears, only the ink stays */
img {
  width: min(90vw, 900px);
  height: auto;
  mix-blend-mode: multiply;
}