:root {
  --ink: #2c2620;
  --muted: #8a8175;
  --bg: #f4efe7;
  --card: #ffffff;
}
* { box-sizing: border-box; }
html, body { margin: 0; height: 100%; }
body {
  background: radial-gradient(120% 120% at 50% 0%, #fbf8f2 0%, var(--bg) 60%);
  color: var(--ink);
  font-family: ui-sans-serif, system-ui, "PingFang SC", "Microsoft YaHei", sans-serif;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}
.wrap { width: min(720px, 100%); text-align: center; }
.title { font-size: clamp(28px, 6vw, 44px); margin: 0 0 6px; letter-spacing: 2px; }
.tagline { color: var(--muted); margin: 0 0 22px; font-size: clamp(14px, 3vw, 17px); }
.stage {
  background: var(--card);
  border-radius: 16px;
  padding: 10px;
  box-shadow: 0 10px 30px rgba(60, 50, 30, 0.12);
}
canvas {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 10px;
  touch-action: manipulation;
}
.hint { color: var(--muted); margin: 16px 0 0; font-size: 14px; }
kbd {
  background: #fff; border: 1px solid #ddd; border-bottom-width: 2px;
  border-radius: 6px; padding: 1px 6px; font: inherit; font-size: 12px;
}