:root {
  --shell-top: #f6c66d;
  --shell-bottom: #e6f2e3;
  --frame-shadow: 0 28px 80px rgba(61, 48, 28, 0.24);
}

* {
  box-sizing: border-box;
}

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

body {
  display: grid;
  place-items: center;
  padding: 16px;
  font-family: "Hiragino Sans", "Yu Gothic", sans-serif;
  background:
    radial-gradient(circle at 16% 8%, rgba(255, 255, 255, 0.68), transparent 28%),
    radial-gradient(circle at 84% 94%, rgba(92, 180, 164, 0.36), transparent 30%),
    linear-gradient(180deg, var(--shell-top), var(--shell-bottom));
}

.app-shell {
  width: 100%;
  display: grid;
  place-items: center;
}

.canvas-frame {
  position: relative;
  width: min(100vw - 24px, 460px);
  aspect-ratio: 720 / 1280;
  overflow: hidden;
  border-radius: 30px;
  background: #fff8ee;
  box-shadow: var(--frame-shadow);
}

#game-canvas {
  display: block;
  width: 100%;
  height: 100%;
  touch-action: none;
}