piano-midi-monitor/public/style.css

html {
  width: 100%;
  height: 100%;
  -webkit-app-region: drag;
}

body {
  margin: 0;
  width: 100%;
  height: 100%;
}

main {
  width: 100%;
  height: 100%;
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: stretch;
}

.theme {
  color: black;
  background-color: white;
}

.button {
  opacity: 0.5;
}

.button:hover {
  opacity: 1;
}

@media (prefers-color-scheme: dark) {
  .theme {
    color: white;
    background-color: black;
  }
}