*, *::before, *::after {
  box-sizing: border-box; 
}

html, body {
  margin: 0;
  padding: 0;
  border: none;
  width: 100%;
  height: 100%;
  touch-action: none;
  -webkit-touch-callout: none;
  -webkit-user-select: none;
  user-select: none;
}

canvas {
  touch-action: none;
  -webkit-touch-callout: none;
  -webkit-user-select: none;
  -webkit-user-drag: none;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

body {
  display: flex;
  flex-direction: column;
  overflow: hidden; 
}
#menu {
  flex-shrink: 0;
}

#app {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  overflow-y: hidden;
  touch-action: none;
  -webkit-touch-callout: none;
  -webkit-user-select: none;
  user-select: none;
}
#play-page {
  flex: 1;
  min-height: 0;
}

#play-page, #config-page {
  width: 100%;
  max-width: 100%;
  overflow: hidden;
  box-sizing: border-box; /* Indispensable */
}