:root{--bg:#0b0d12;--bg-2:#0e1117;--surface:#161a22;--surface-2:#1c212b;--text:#eef1f6;--muted:#9aa4b5;--faint:#6b7385;--accent:#6ee7b7;--accent-2:#34d399;--accent-ink:#052b1e;--danger:#fca5a5;--border:#252b37;--radius:14px;--radius-lg:22px;--space:clamp(.85rem, 2.4vw, 1.25rem);--maxw:56rem;--shadow:0 1px 0 #ffffff08, 0 10px 30px -12px #0009;--lightningcss-light: ;--lightningcss-dark:initial;color-scheme:dark}*{box-sizing:border-box}html,body{margin:0;padding:0}body{background:radial-gradient(1200px 600px at 80% -10%, #6ee7b714, transparent 60%), radial-gradient(900px 500px at -10% 10%, #34d3990f, transparent 55%), var(--bg);color:var(--text);-webkit-text-size-adjust:100%;text-rendering:optimizelegibility;font:16px/1.6 system-ui,-apple-system,Segoe UI,Roboto,sans-serif}.app-shell{flex-direction:column;min-height:100dvh;display:flex}.app-shell>header{z-index:20;padding:.75rem var(--space);background:color-mix(in srgb, var(--bg-2) 80%, 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1.15rem;font-weight:650;text-decoration:none;display:inline-flex}.btn.ghost{background:var(--surface);color:var(--text);border-color:var(--border)}.btn:hover{filter:brightness(1.05)}.cards{gap:var(--space);grid-template-columns:repeat(auto-fit,minmax(min(100%,15rem),1fr));display:grid}.card{color:inherit;background:linear-gradient(180deg, var(--surface), var(--surface-2));border:1px solid var(--border);border-radius:var(--radius-lg);box-shadow:var(--shadow);padding:1.1rem 1.2rem 1.25rem;text-decoration:none;transition:transform .14s,border-color .14s;display:block}.card:hover{border-color:color-mix(in srgb, var(--accent) 40%, var(--border));transform:translateY(-3px)}.card-icon{font-size:1.6rem}.card h3{letter-spacing:-.01em;margin:.5rem 0 .3rem;font-size:1.1rem}.card p{font-size:.92rem}input,button,select,textarea{font:inherit}input,select,textarea{background:var(--bg-2);width:100%;max-width:100%;min-height:46px;color:var(--text);border:1px solid var(--border);border-radius:var(--radius);padding:.55rem .9rem}input::placeholder,textarea::placeholder{color:var(--faint)}input:focus-visible,button:focus-visible,select:focus-visible,textarea:focus-visible{outline:2px solid var(--accent);outline-offset:2px}button{border-radius:var(--radius);cursor:pointer;background:linear-gradient(180deg, var(--accent), var(--accent-2));min-height:46px;color:var(--accent-ink);border:1px solid #0000;padding:.55rem 1.05rem;font-weight:650;transition:filter .12s,transform 80ms}button:hover{filter:brightness(1.06)}button:active{transform:translateY(1px)}button:disabled{opacity:.55;cursor:default}button.secondary{background:var(--surface);color:var(--text);border-color:var(--border)}.field-row{flex-wrap:wrap;align-items:center;gap:.6rem;display:flex}.field-row input,.field-row select{flex:1;min-width:8rem}.field-row button{flex:none}label{color:var(--muted);font-size:.9rem;font-weight:550}textarea.answer{resize:vertical;min-height:7rem;line-height:1.5}.worksheet{flex-wrap:wrap;gap:.5rem;margin:.4rem 0 .25rem;display:flex}.cell{text-align:center;background:var(--bg-2);width:3.1rem;max-width:3.1rem;height:3.5rem;padding:0;font:1.6rem/1 ui-monospace,SF Mono,Menlo,monospace}.cell-error{border-color:var(--danger);outline:2px solid var(--danger);background:color-mix(in srgb, var(--danger) 12%, var(--bg-2))}.verdict{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);color:var(--text);border-left-width:4px;gap:.5rem;margin:0;padding:.85rem 1rem;display:flex}.verdict-ok{border-left-color:var(--accent)}.verdict-bad{border-left-color:var(--danger)}.verdict.coach{border-left-color:var(--accent-2);background:color-mix(in srgb, var(--accent) 7%, var(--surface))}.muted{color:var(--muted)}select{min-height:46px}table.gradebook{border-collapse:collapse;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);width:100%;overflow:hidden}table.gradebook th,table.gradebook td{text-align:left;border-bottom:1px solid var(--border);padding:.7rem .85rem}table.gradebook thead th{color:var(--muted);text-transform:uppercase;letter-spacing:.04em;background:var(--bg-2);font-size:.85rem;font-weight:650}table.gradebook tbody tr:last-child td{border-bottom:0}.canvas-pad{border:1px solid var(--border);border-radius:var(--radius);touch-action:none;cursor:crosshair;width:100%;max-width:380px;height:190px;box-shadow:var(--shadow);background:#fff}.worksheet-grid{gap:.35rem;display:grid}.worksheet-row{flex-wrap:wrap;align-items:center;gap:.75rem;display:flex}.worksheet-row .row-label{min-width:4.5rem;color:var(--muted);font:.95rem ui-monospace,Menlo,monospace}