html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: #000;
  overscroll-behavior: none;
  -webkit-user-select: none;
  user-select: none;
  -webkit-touch-callout: none;
  -webkit-tap-highlight-color: transparent;
  /* iOS Safari ignores user-scalable=no: this is what stops double-tap and pinch zoom. */
  touch-action: none;
}

body {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* With touch controls, pin the game to the top and leave the bottom for the pad. */
.touch-ui body {
  align-items: flex-start;
  padding-top: env(safe-area-inset-top, 0px);
  box-sizing: border-box;
}

#screen {
  display: block;
  background: #000;
  touch-action: none;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
  image-rendering: pixelated;
}

/* ---- On-screen touch controls (only on touch devices) -------------------------------- */

.touch {
  display: none;
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 10;
}

.touch-ui .touch {
  display: block;
}

.touch-pad,
.touch-fire {
  position: absolute;
  bottom: calc(env(safe-area-inset-bottom, 0px) + 20px);
  pointer-events: auto;
  touch-action: none;
  background: rgba(255, 255, 255, 0.16);
  border: 2px solid rgba(255, 255, 255, 0.38);
  -webkit-backdrop-filter: blur(1px);
}

/* Default: FIRE on the left, steering pad on the right, like the keyboard (Space under
   the left hand, arrows under the right). The SETTINGS screen can swap them. */
.touch-pad {
  right: calc(env(safe-area-inset-right, 0px) + 16px);
  width: min(38vw, 168px);
  height: min(38vw, 168px);
  border-radius: 22%;
}

.touch-fire {
  left: calc(env(safe-area-inset-left, 0px) + 16px);
  width: min(30vw, 124px);
  height: min(30vw, 124px);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: rgba(255, 255, 255, 0.85);
  font: bold 15px/1 monospace;
  letter-spacing: 2px;
}

.fire-right .touch-pad {
  left: calc(env(safe-area-inset-left, 0px) + 16px);
  right: auto;
}

.fire-right .touch-fire {
  right: calc(env(safe-area-inset-right, 0px) + 16px);
  left: auto;
}

.touch-fire.on,
.arrow.on {
  background-color: rgba(255, 255, 255, 0.4);
}

.touch-fire.on {
  border-radius: 50%;
}

.arrow {
  position: absolute;
  width: 0;
  height: 0;
  border: 11px solid transparent;
  opacity: 0.8;
  border-radius: 2px;
}

.arrow.up { top: 8%; left: 50%; margin-left: -11px; border-bottom-color: #fff; border-top-width: 0; }
.arrow.down { bottom: 8%; left: 50%; margin-left: -11px; border-top-color: #fff; border-bottom-width: 0; }
.arrow.left { left: 8%; top: 50%; margin-top: -11px; border-right-color: #fff; border-left-width: 0; }
.arrow.right { right: 8%; top: 50%; margin-top: -11px; border-left-color: #fff; border-right-width: 0; }

.arrow.on { background-color: transparent; opacity: 1; filter: drop-shadow(0 0 4px #fff); }