:root{--gb-bg: #070b14;--gb-surface: #121826;--gb-surface-elevated: #1a2335;--gb-ink: #f4f7ff;--gb-muted: #9aa6c2;--gb-accent: #5b8cff;--gb-accent-hot: #ff5d8f;--gb-success: #3ddc97;--gb-warning: #ffc857;--gb-danger: #ff6b6b;--gb-radius-sm: 10px;--gb-radius-md: 16px;--gb-radius-lg: 24px;--gb-font: "Segoe UI", "Hiragino Sans", "Noto Sans JP", sans-serif;color-scheme:dark}@media(prefers-reduced-motion:reduce){:root{--gb-motion: 0ms}}:root{--gb-motion: .22s}*{box-sizing:border-box}html,body,#root{min-height:100%;height:100%}body{margin:0;font-family:var(--gb-font);background:radial-gradient(circle at top,rgba(255,93,143,.16),transparent 40%),var(--gb-bg);color:var(--gb-ink);touch-action:manipulation;-webkit-user-select:none;user-select:none}button{font:inherit;border:0;cursor:pointer;-webkit-tap-highlight-color:transparent}.app{width:min(720px,100%);min-height:100%;margin:0 auto;padding:calc(16px + env(safe-area-inset-top)) calc(16px + env(safe-area-inset-right)) calc(20px + env(safe-area-inset-bottom)) calc(16px + env(safe-area-inset-left));display:grid;gap:16px;align-content:start}.panel{background:linear-gradient(180deg,var(--gb-surface-elevated),var(--gb-surface));border:1px solid rgba(255,255,255,.06);border-radius:var(--gb-radius-lg);padding:18px}.eyebrow{display:inline-flex;padding:6px 12px;border-radius:999px;background:#ff5d8f29;color:#ff9aba;font-size:.78rem;letter-spacing:.08em;text-transform:uppercase}h1,h2,p{margin:0}h1{font-size:clamp(1.8rem,7vw,2.6rem);line-height:1.15}.muted{color:var(--gb-muted);line-height:1.55}.stack{display:grid;gap:12px}.row{display:flex;flex-wrap:wrap;gap:10px}.button{min-height:48px;padding:0 18px;border-radius:999px;font-weight:700}.button.primary{background:var(--gb-accent);color:#07101f}.button.hot{background:var(--gb-accent-hot);color:#1a0610}.button.ghost{background:#ffffff14;color:var(--gb-ink)}.level-card{display:grid;gap:8px;width:100%;text-align:left;padding:16px;border-radius:var(--gb-radius-md);background:#ffffff0a;color:inherit;border:1px solid transparent}.level-card:focus-visible,.button:focus-visible{outline:2px solid var(--gb-accent);outline-offset:2px}.arena{position:relative;min-height:min(62vh,560px);border-radius:calc(var(--gb-radius-lg) + 4px);display:grid;place-items:center;overflow:hidden;border:1px solid rgba(255,255,255,.08);background:#0a1020}.arena.ready{background:#10182b}.arena.stimulus{background:#151018}.arena.feedback-hit{background:#08261a}.arena.feedback-miss{background:#2a1014}.prompt{text-align:center;padding:24px;display:grid;gap:10px}.stimulus{width:min(46vw,180px);aspect-ratio:1;display:block;box-shadow:0 0 0 12px #ffffff14;animation:pop var(--gb-motion) ease-out}.stimulus.circle{border-radius:999px}.stimulus.square{border-radius:28px}.stimulus.diamond{border-radius:28px;transform:rotate(45deg)}.stimulus.cyan{background:#5b8cff}.stimulus.magenta{background:#ff5d8f}.stimulus.amber{background:#ffc857}.stimulus.lime{background:#3ddc97}.stats{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.stat{padding:12px;border-radius:var(--gb-radius-md);background:#ffffff0a}.stat strong{display:block;font-size:1.3rem}.hud{display:flex;justify-content:space-between;gap:12px;color:var(--gb-muted);font-size:.92rem}@keyframes pop{0%{transform:scale(.86);opacity:.4}to{transform:scale(1);opacity:1}}@media(prefers-reduced-motion:reduce){.stimulus{animation:none}}