:root { --rnc-blue:#149bd7; --rnc-ink:#102131; --rnc-line:#c9dbe6; --rnc-muted:#526c7a; --rnc-green:#157347; --rnc-red:#b4232f; }
* { box-sizing:border-box; }
[hidden] { display:none!important; }
html,body { min-height:100%; }
body { margin:0; color:var(--rnc-ink); background:#edf5f9; font-family:Arial,Helvetica,sans-serif; }
button,input,select { font:inherit; }
.app { min-height:100vh; display:grid; grid-template-rows:auto minmax(0,1fr); }
.topbar { min-height:72px; display:grid; grid-template-columns:minmax(240px,1fr) auto; align-items:center; gap:16px; padding:11px 18px; color:#fff; background:#071018; }
.brand { min-width:0; display:flex; align-items:center; gap:14px; }
.brand-logo { display:inline-flex; border-radius:6px; }
.brand-logo img { width:142px; height:auto; display:block; }
.brand h1 { margin:0; color:#fff; font-size:clamp(1.35rem,2vw,2rem); line-height:1.05; }
.top-actions { display:flex; align-items:center; justify-content:flex-end; gap:8px; }
.icon-button { width:48px; min-width:48px; min-height:48px; display:inline-grid; place-items:center; padding:0; border:2px solid #263d51; border-radius:8px; color:#fff; background:#122436; cursor:pointer; }
.icon-button:hover,.icon-button:focus-visible { border-color:#8fd8f3; color:#06111a; background:var(--rnc-blue); }
.icon { width:24px; height:24px; display:block; pointer-events:none; }
.home-button { min-height:48px; display:inline-flex; align-items:center; justify-content:center; padding:0 14px; border:2px solid #263d51; border-radius:8px; color:#fff; background:#122436; font-weight:800; text-decoration:none; }
.home-button:hover,.home-button:focus-visible { border-color:#8fd8f3; color:#06111a; background:var(--rnc-blue); }
.rnc-app { min-height:calc(100vh - 72px); display:grid; grid-template-rows:auto minmax(0,1fr); gap:0; color:var(--rnc-ink); background:#edf5f9; }
.rnc-toolbar { min-height:68px; display:flex; flex-wrap:wrap; align-items:end; gap:10px; padding:10px 16px; border-bottom:1px solid var(--rnc-line); background:#fff; }
.rnc-choice-field,.rnc-select-label,.rnc-target-field,.rnc-repair-config { margin:0; }
.rnc-choice-field { min-width:250px; padding:0; border:0; }
.rnc-choice-field legend,.rnc-select-label span,.rnc-target-field span,.rnc-repair-config span,.rnc-group-select span { display:block; margin-bottom:5px; color:var(--rnc-muted); font-size:.82rem; font-weight:800; }
.rnc-choice-row { display:flex; flex-wrap:wrap; gap:8px; }
.rnc-choice-row label { min-height:48px; display:inline-flex; align-items:center; padding:7px 11px; border:1px solid #9fb8c8; border-radius:8px; color:var(--rnc-ink); background:#fff; font-size:.92rem; font-weight:800; cursor:pointer; }
.rnc-choice-row label:has(input:checked) { border-color:#087eaf; color:#fff; background:#087eaf; }
.rnc-choice-row input { margin-right:7px; accent-color:#006b99; }
.rnc-choice-row label:has(input:disabled) { opacity:.48; cursor:not-allowed; }
.rnc-select-label select,.rnc-target-field input,.rnc-repair-config input,.rnc-group-select select,.rnc-numeric-entry input,.rnc-challenge-panel input { min-height:48px; padding:8px 11px; border:1px solid #9fb8c8; border-radius:8px; color:var(--rnc-ink); background:#fff; font-weight:800; }
.rnc-select-label select { min-width:190px; }
.rnc-target-field,.rnc-repair-config { display:grid; gap:0; }
.rnc-target-field input { width:130px; }
.rnc-repair-config input { width:190px; text-transform:uppercase; }
.rnc-toolbar-actions { display:flex; flex:1 1 420px; flex-wrap:wrap; justify-content:flex-end; gap:8px; }
.rnc-button { min-height:48px; padding:0 15px; border:1px solid #9fb8c8; border-radius:8px; color:var(--rnc-ink); background:#fff; font-weight:800; cursor:pointer; }
.rnc-button:hover,.rnc-button:focus-visible { border-color:#006b99; box-shadow:0 0 0 3px rgba(20,155,215,.18); outline:0; }
.rnc-button.rnc-primary { border-color:#087eaf; color:#fff; background:var(--rnc-blue); }
.rnc-button:disabled { opacity:.48; cursor:not-allowed; }
.rnc-workspace { min-width:0; min-height:0; display:grid; grid-template-columns:minmax(310px,370px) minmax(0,1fr); gap:14px; padding:14px; }
.rnc-work-panel,.rnc-model-panel { min-width:0; min-height:0; border:1px solid var(--rnc-line); border-radius:12px; background:#fff; box-shadow:0 8px 22px rgba(7,32,48,.07); }
.rnc-work-panel { overflow:auto; padding:14px; }
.rnc-prompt-card { margin-bottom:12px; padding:13px 14px; border-radius:9px; color:#fff; background:#073047; }
.rnc-prompt-card h2 { margin:0; color:#fff; font-size:clamp(1.08rem,2vw,1.35rem); line-height:1.2; }
.rnc-response-card,.rnc-challenge-panel { margin:0 0 10px; padding:12px; border:1px solid var(--rnc-line); border-radius:9px; }
.rnc-step-heading { display:grid; gap:3px; margin-bottom:12px; padding-bottom:10px; border-bottom:1px solid var(--rnc-line); }
.rnc-step-heading span { color:#087eaf; font-size:.78rem; font-weight:900; letter-spacing:.05em; text-transform:uppercase; }
.rnc-step-heading strong { font-size:1.05rem; }
.rnc-numeric-entry label,.rnc-challenge-panel label { display:grid; gap:5px; color:var(--rnc-muted); font-size:.82rem; font-weight:800; }
.rnc-numeric-entry input { width:min(100%,220px); font-size:1.2rem; }
.rnc-roman-entry-heading { display:flex; align-items:center; justify-content:space-between; gap:10px; margin-bottom:9px; }
.rnc-roman-entry-heading > p,.rnc-combine-entry > p { margin:0; color:var(--rnc-muted); font-weight:800; line-height:1.35; }
.rnc-symbol-values-toggle { display:flex; align-items:center; gap:6px; color:var(--rnc-muted); font-size:.78rem; font-weight:800; white-space:nowrap; }
.rnc-current-entry { min-height:52px; display:flex; align-items:center; justify-content:center; margin-bottom:10px; border:2px solid #9fb8c8; border-radius:8px; color:#006b99; background:#f7fbfd; font-size:1.75rem; font-weight:900; letter-spacing:.08em; }
.rnc-undo { width:100%; margin-top:9px; }
.rnc-group-select { display:block; margin-bottom:10px; }
.rnc-group-select select { width:100%; }
.rnc-palette { display:grid; grid-template-columns:repeat(4,minmax(58px,1fr)); gap:8px; }
.rnc-symbol-button { min-height:70px; border:1px solid #9fb8c8; border-radius:8px; color:var(--rnc-ink); background:#f7fbfd; cursor:pointer; }
.rnc-symbol-button:hover,.rnc-symbol-button:focus-visible { border-color:#006b99; box-shadow:0 0 0 3px rgba(20,155,215,.18); outline:0; }
.rnc-symbol-button span,.rnc-symbol-button small { display:block; }
.rnc-symbol-button span { color:#006b99; font-size:1.75rem; font-weight:900; line-height:1; }
.rnc-symbol-button small { margin-top:4px; color:var(--rnc-muted); font-size:.78rem; font-weight:800; }
.rnc-symbol-button small.is-hidden { display:none; }
.rnc-attempt-row { display:grid; grid-template-columns:minmax(0,1fr) auto; align-items:center; gap:8px 10px; margin-top:12px; padding-top:12px; border-top:1px solid var(--rnc-line); }
.rnc-attempt-row strong { grid-column:1/-1; }
.rnc-attempt { min-height:42px; display:flex; align-items:center; padding:5px 10px; border-radius:7px; color:#006b99; background:#f2f7fa; font-size:1.6rem; font-weight:900; letter-spacing:.08em; overflow-wrap:anywhere; }
.rnc-group-tokens { display:grid; grid-template-columns:repeat(2,minmax(0,1fr)); gap:8px; }
.rnc-group-token { min-height:62px; border:1px solid #9fb8c8; border-radius:8px; color:var(--rnc-ink); background:#f7fbfd; cursor:pointer; }
.rnc-group-token:hover,.rnc-group-token:focus-visible { border-color:#006b99; box-shadow:0 0 0 3px rgba(20,155,215,.18); outline:0; }
.rnc-group-token:disabled { opacity:.45; cursor:not-allowed; }
.rnc-group-token span,.rnc-group-token small { display:block; }
.rnc-group-token span { color:#006b99; font-size:1.45rem; font-weight:900; }
.rnc-group-token small { margin-top:3px; color:var(--rnc-muted); font-size:.74rem; font-weight:800; }
.rnc-hint { min-height:1.2em; margin:10px 0 0; color:#8a6100; font-weight:800; line-height:1.35; }
.rnc-feedback { min-height:54px; display:flex; align-items:center; margin:4px 0 0; padding:10px 12px; border-left:5px solid #6f8794; border-radius:7px; background:#f2f7fa; font-weight:800; line-height:1.4; }
.rnc-feedback[data-tone="success"] { border-left-color:var(--rnc-green); color:#0b5934; background:#eef9f3; }
.rnc-feedback[data-tone="warning"] { border-left-color:#b07a00; color:#704e00; background:#fff8e7; }
.rnc-challenge-panel { border-color:#d4b15a; background:#fffaf0; }
.rnc-challenge-panel input { width:100%; margin-top:5px; font-size:1.2rem; }
.rnc-challenge-panel .rnc-button { margin-top:9px; }
.rnc-challenge-panel p { min-height:1.2em; margin:9px 0 0; color:#704e00; font-weight:800; line-height:1.4; }
.rnc-app > .rnc-print-surface { display:none; }
.rnc-model-panel { display:grid; grid-template-rows:minmax(0,1fr); overflow:hidden; padding:12px; }
.rnc-model-host { min-height:390px; display:grid; place-items:stretch; }
.rnc-model-host .question-visual { width:100%; height:100%; min-width:0; margin:0; display:grid; grid-template-rows:auto minmax(0,1fr) auto; }
.rnc-model-host .diagram-frame,.rnc-model-host svg { width:100%; height:100%; min-height:360px; }
.rnc-model-host figcaption { position:absolute; left:-10000px; width:1px; height:1px; overflow:hidden; white-space:nowrap; }
.rnc-model-host .part-whole-model .diagram-visual { max-height:none; }
.rnc-instructions { width:min(720px,calc(100vw - 28px)); max-height:calc(100vh - 28px); padding:0; border:0; border-radius:11px; color:var(--rnc-ink); box-shadow:0 24px 70px rgba(0,0,0,.35); }
.rnc-instructions::backdrop { background:rgba(4,19,29,.62); }
.rnc-dialog-header { display:flex; align-items:center; justify-content:space-between; gap:15px; padding:14px 17px; color:#fff; background:#071018; }
.rnc-dialog-header h2 { margin:0; }
.rnc-dialog-body { padding:17px 20px; line-height:1.52; overflow:auto; }
.rnc-dialog-body li { margin-bottom:7px; }
.rnc-app:focus-visible { outline:4px solid rgba(20,155,215,.4); outline-offset:-4px; }
@media (prefers-reduced-motion:reduce) { .rnc-app * { scroll-behavior:auto!important; transition:none!important; animation:none!important; } }
@media (min-width:901px) { .rnc-app { height:calc(100vh - 72px); overflow:hidden; } }
@media (max-width:900px) { .app { display:block; }.topbar { grid-template-columns:1fr; }.top-actions { justify-content:flex-start; flex-wrap:wrap; }.rnc-toolbar { align-items:stretch; }.rnc-toolbar > label { flex:1 1 145px; }.rnc-select-label select,.rnc-target-field input,.rnc-repair-config input { width:100%; }.rnc-toolbar-actions { justify-content:flex-start; }.rnc-workspace { grid-template-columns:1fr; }.rnc-model-panel { min-height:720px; }.rnc-model-host,.rnc-model-host .diagram-frame,.rnc-model-host svg { min-height:650px; }.rnc-work-panel { overflow:visible; }.rnc-app { display:block; min-height:0; } }
@media (max-width:440px) { .brand h1 { font-size:1.25rem; }.brand-logo img { width:122px; }.rnc-toolbar-actions .rnc-button { flex:1 1 30%; padding-inline:9px; }.rnc-choice-field { min-width:100%; }.rnc-attempt-row { grid-template-columns:1fr; }.rnc-attempt-row .rnc-button { width:100%; }.rnc-model-panel { min-height:670px; padding:6px; }.rnc-model-host,.rnc-model-host .diagram-frame,.rnc-model-host svg { min-height:620px; } }
@media print {
  @page { size:A4 landscape; margin:8mm; }
  html,body { width:100%; height:auto!important; overflow:visible!important; background:#fff!important; }
  .topbar,.rnc-toolbar,.rnc-instructions,.rnc-challenge-panel,.rnc-response-card,.rnc-palette,.rnc-group-select,.rnc-attempt-row,.rnc-hint,.rnc-feedback,.classroom-tools-layer,.annotation-toolbar { display:none!important; }
  .app,.rnc-app,.rnc-workspace { min-height:0!important; height:auto!important; }
  .rnc-app { display:block; background:#fff; }.rnc-workspace { display:grid!important; grid-template-columns:72mm minmax(0,1fr); gap:5mm; padding:0; }.rnc-work-panel { display:block!important; visibility:visible!important; }.rnc-work-panel,.rnc-model-panel { height:145mm; overflow:hidden; border:1px solid #93a9b7; box-shadow:none; padding:4mm; break-inside:avoid; }.rnc-prompt-card { display:block!important; visibility:visible!important; margin-bottom:2mm; padding:3mm; }.rnc-prompt-card h2 { font-size:17pt; }.rnc-model-host { min-height:102mm; }.rnc-model-host .diagram-frame,.rnc-model-host svg { min-height:96mm; }.rnc-app > .rnc-print-surface { position:fixed; left:8mm; right:8mm; bottom:5mm; display:flex!important; justify-content:space-between; align-items:end; margin:0; border-top:1px solid #c7d7df; padding-top:2mm; color:var(--rnc-muted); font-size:8pt; }
  .rnc-print-surface .print-logo { width:34mm; height:auto; }.rnc-print-surface .print-copyright { font-size:8pt; }
}