.math{max-width:480px;margin:0 auto;padding:1rem;min-height:100dvh;display:flex;flex-direction:column}.back{align-self:flex-start;text-decoration:none;color:var(--muted);font-size:.9rem}.hud{display:flex;justify-content:space-between;margin:1rem 0 2rem;font-size:1.3rem;font-variant-numeric:tabular-nums}.hud-item{display:flex;flex-direction:column;align-items:center}.hud-label{font-size:.7rem;text-transform:uppercase;letter-spacing:.08em;color:var(--muted)}.overlay,.play{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:1.2rem;text-align:center}.equation{font-size:clamp(2.5rem,12vw,4rem);font-weight:700;font-variant-numeric:tabular-nums}.answer{font:inherit;font-size:2rem;width:5em;text-align:center;padding:.4em;border-radius:12px;border:2px solid var(--panel);background:var(--panel);color:var(--text)}.answer:focus{outline:none;border-color:var(--accent)}.feedback{min-height:1.4em;font-weight:600}.feedback.correct{color:var(--accent-2)}.feedback.wrong{color:var(--danger)}