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24px}.board-canvas.tool-pen,.board-canvas.tool-rect,.board-canvas.tool-ellipse,.board-canvas.tool-arrow{cursor:crosshair}.board-canvas.tool-select{cursor:grab}.board-canvas.tool-text{cursor:text}.board-canvas.tool-eraser{cursor:cell}.board-text-input{position:absolute;min-width:160px;background:#0f1115f2;border:1px solid var(--accent);border-radius:6px;padding:4px 6px;color:var(--text);font-family:inherit;line-height:1.25;resize:none}.board-hint{position:absolute;bottom:10px;right:12px;font-size:11px;color:var(--muted);background:#0f1115cc;padding:4px 9px;border-radius:5px;pointer-events:none}.lesson-tabs{display:flex;gap:6px}.lesson-tab{background:transparent;border:1px solid var(--border);color:var(--muted);border-radius:8px;padding:7px 16px;font-size:13px;cursor:pointer}.lesson-tab.active{background:var(--accent);color:#fff;border-color:var(--accent)}:root{--bg: #0f1115;--surface: #181b22;--border: #272b35;--text: #e8eaed;--muted: #9aa0aa;--accent: #6366f1;--danger: 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section{margin-top:32px}.topbar{display:flex;justify-content:space-between;align-items:center;padding-bottom:16px;border-bottom:1px solid var(--border)}.inline-form{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:16px}.inline-form input{flex:1;min-width:140px}.list{display:flex;flex-direction:column;gap:8px}.row{background:var(--surface);border:1px solid var(--border);border-radius:10px;padding:14px 16px;display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap}.row-actions{display:flex;gap:8px;align-items:center}.row.column{flex-direction:column;align-items:stretch}.row-main{display:flex;justify-content:space-between;align-items:center;gap:12px}.paid-badge{display:inline-block;margin-top:6px;font-size:12px;padding:2px 8px;border-radius:5px;background:#ef444426;color:#fca5a5}.paid-badge.active{background:#22c55e26;color:#86efac}.billing-editor{display:flex;flex-direction:column;gap:12px;margin-top:14px;padding-top:14px;border-top:1px solid 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video{width:100%;height:100%;object-fit:cover}.blur-layer{position:absolute;top:0;right:0;bottom:0;left:0;width:100%;height:100%;object-fit:cover}.blur-layer.hidden{display:none}.tile-label{position:absolute;bottom:8px;left:8px;background:#000000a6;padding:3px 8px;border-radius:5px;font-size:12px}.controls{display:flex;justify-content:center;align-items:center;gap:12px;padding:16px;border-top:1px solid var(--border);flex-wrap:wrap}.round{min-width:62px;height:42px;border-radius:21px;background:#2a2e38;font-size:13px}.round.on{background:var(--accent)}.round.off{background:var(--danger)}.blur-control{display:flex;align-items:center;gap:10px}.pill{background:#2a2e38;border-radius:21px;height:42px;font-size:13px}.pill.on{background:var(--accent)}input[type=range]{width:110px;padding:0}.unit-row{text-decoration:none;color:var(--text);transition:border-color 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