:root {
  --shell-top: #b9ecff;
  --shell-bottom: #fff3a5;
  --frame-shadow: 0 24px 70px rgba(47, 81, 105, 0.22);
}

* {
  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", Meiryo, sans-serif;
  background:
    radial-gradient(circle at 12% 12%, rgba(255, 255, 255, 0.74), transparent 30%),
    radial-gradient(circle at 88% 88%, rgba(64, 192, 164, 0.26), transparent 34%),
    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, 1280px);
  aspect-ratio: 1280 / 720;
  overflow: hidden;
  border-radius: 16px;
  background: #fdf7d5;
  box-shadow: var(--frame-shadow);
}

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

.overlay-input {
  position: absolute;
  left: -9999px;
  top: -9999px;
  width: 230px;
  height: 44px;
  border: 2px solid rgba(31, 112, 142, 0.34);
  border-radius: 8px;
  padding: 0 14px;
  outline: none;
  color: #273344;
  background: rgba(255, 255, 255, 0.96);
  font-family: "Hiragino Sans", "Yu Gothic", Meiryo, sans-serif;
  font-size: 18px;
  font-weight: 800;
  text-align: center;
}

.overlay-input:focus {
  border-color: rgba(29, 139, 184, 0.78);
  box-shadow: 0 0 0 4px rgba(29, 139, 184, 0.16);
}