:root{font-family:system-ui,-apple-system,sans-serif;color:#111827;background:#f7f7f5}*{box-sizing:border-box}body{margin:0}main{max-width:720px;margin:auto;padding:28px 20px 110px}.card{background:#fff;border-radius:20px;padding:22px;box-shadow:0 8px 30px #0000000d;margin:14px 0}h1{font-size:2.1rem;margin:.2em 0}h2{margin-top:0}.muted{color:#6b7280}.grid{display:grid;gap:12px}.btn{width:100%;padding:16px;border:0;border-radius:14px;font-size:1rem;font-weight:650;background:#111827;color:#fff}.btn.secondary{background:#e5e7eb;color:#111827}.scale{display:grid;grid-template-columns:repeat(6,1fr);gap:6px}.scale button{padding:10px 0;border:1px solid #ddd;background:#fff;border-radius:9px}.scale button.sel{background:#111827;color:#fff}.timer{font-size:4rem;font-variant-numeric:tabular-nums;text-align:center}.breath{width:150px;height:150px;border-radius:50%;background:#dbeafe;margin:30px auto;transform:scale(.7);transition:transform 4s ease-in-out}.breath.out{transform:scale(.45);transition-duration:6s}.stop{position:fixed;left:20px;right:20px;bottom:20px;padding:16px;border:0;border-radius:14px;background:#b91c1c;color:#fff;font-weight:800;font-size:1.1rem}.hidden{display:none}.small{font-size:.9rem}.rt{height:250px;display:grid;place-items:center;border-radius:18px;background:#e5e7eb;user-select:none}.rt.go{background:#fff;border:4px solid #111827}.rt span{font-size:1.3rem;font-weight:700}