:root{--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light;--bg:#eef1f4;--surface:#fff;--ink:#1c2430;--muted:#667085;--line:#e4e7ec;--accent:#2f6fed;--done:#1f8a5b;--retry:#b86e00;--shadow:0 12px 40px #1c24300f;font-family:Segoe UI,Helvetica Neue,Arial,sans-serif;font-size:16px;line-height:1.4}*{box-sizing:border-box}body{background:var(--bg);color:var(--ink);margin:0}button,input{font:inherit;color:inherit}button{cursor:pointer}button:focus-visible,input:focus-visible{outline:2px solid var(--accent);outline-offset:2px}button:active:not(:disabled){transform:scale(.98)}.app{justify-content:center;min-height:100dvh;display:flex}.frame{background:var(--surface);flex-direction:column;width:100%;max-width:28rem;height:100dvh;display:flex}.top{padding:calc(.85rem + env(safe-area-inset-top)) 1rem .75rem;justify-content:space-between;align-items:center;gap:1rem;display:flex}.child-name,.screen-title{text-overflow:ellipsis;white-space:nowrap;margin:0;font-size:1.05rem;font-weight:600;overflow:hidden}.points{color:var(--muted);font-variant-numeric:tabular-nums;white-space:nowrap;margin:0}.main{flex:1;padding:.25rem 1rem 1.25rem;overflow:auto}.nav{border-top:1px solid var(--line);background:var(--surface);padding-bottom:env(safe-area-inset-bottom);flex:none;grid-template-columns:repeat(3,1fr);display:grid}.nav button{color:var(--muted);background:0 0;border:0;min-height:3.25rem;padding:.75rem .25rem}.nav button[aria-current=page]{color:var(--accent);font-weight:600}.gate{padding:calc(1.5rem + env(safe-area-inset-top)) 1.5rem 1.5rem;flex-direction:column;flex:1;gap:.75rem;display:flex;overflow:auto}.gate.center{justify-content:center}.quiet{color:var(--muted);margin:0}.screen-title{margin-bottom:.25rem}.stack{flex-direction:column;gap:.75rem;display:flex}.grade-label{margin:0 0 .75rem;font-size:1.15rem;font-weight:600}.card{border:2px solid var(--accent);background:var(--surface);text-align:start;border-radius:1rem;width:100%;padding:1rem 1.05rem}.card.done{border-color:var(--done)}.card.quiet{border-color:var(--line);color:var(--muted)}.card p{color:var(--muted);margin:.35rem 0 0;font-size:.95rem}.card .card-title{color:inherit;margin-top:0;font-size:1.05rem;font-weight:600}.field{flex-direction:column;gap:.4rem;display:flex}.field span{color:var(--muted)}input{border:1px solid var(--line);background:var(--surface);border-radius:.8rem;width:100%;min-height:3rem;padding-inline:.9rem}.primary{background:var(--accent);color:#fff;border:0;border-radius:999px;width:100%;min-height:3rem}.choice{border:1px solid var(--line);background:var(--surface);text-align:start;border-radius:.9rem;width:100%;min-height:3rem;padding-inline:.95rem}.choice[aria-current=true]{border-color:var(--accent);color:var(--accent)}.equation{text-align:center;letter-spacing:.04em;margin:1.5rem 0 .5rem;font-size:3rem}.count,.feedback{text-align:center;margin:0}.count{color:var(--muted)}.feedback{min-height:1.5rem;margin:.75rem 0 1rem;font-weight:600}.feedback.ok{color:var(--done)}.feedback.retry{color:var(--retry)}.pad{grid-template-columns:repeat(3,1fr);gap:.6rem;display:grid}.pad button{border:1px solid var(--line);background:var(--surface);border-radius:.9rem;min-height:3.25rem;font-size:1.35rem}.pad button:disabled{opacity:.45}.reward{text-align:center;flex-direction:column;justify-content:center;gap:.75rem;min-height:16rem;display:flex}.reward h1,.reward p{margin:0}.section-label{color:var(--muted);margin:.5rem 0 0;font-size:.9rem}.notice{color:var(--retry);text-align:start;margin:0 0 .75rem}@media (width>=40rem){.app{align-items:center;padding:2rem 1rem}.frame{border:1px solid var(--line);height:min(100dvh - 4rem,52rem);box-shadow:var(--shadow);border-radius:1.5rem}}