*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}body{overflow:hidden;font-family:system-ui,-apple-system,sans-serif}.app{display:flex;flex-direction:column;height:100vh}.topbar{display:flex;align-items:center;gap:10px;padding:0 18px;height:56px;background:#1e293b;border-bottom:1px solid #334155;flex-shrink:0}.topbar label{color:#cbd5e1;font-size:14px;font-weight:500}#n-input{width:72px;padding:6px 10px;background:#334155;border:1.5px solid #475569;border-radius:7px;color:#f1f5f9;font-size:14px;text-align:center}#n-input:focus{outline:none;border-color:#60a5fa;background:#3b4f6b}.btn{padding:7px 18px;border:none;border-radius:7px;font-size:13px;font-weight:600;cursor:pointer;letter-spacing:.02em;transition:background .12s}.btn-primary{background:#3b82f6;color:#fff}.btn-primary:hover{background:#2563eb}.btn-secondary{background:#475569;color:#fff}.btn-secondary:hover{background:#334155}.mode-badge{margin-left:auto;font-size:12px;font-weight:600;color:#475569;letter-spacing:.06em;text-transform:uppercase;transition:color .15s}.mode-badge--active{color:#f59e0b}.canvas{flex:1;display:block;background:#f8fafc;cursor:default}.canvas--crosshair{cursor:crosshair}.item{cursor:grab}.item:active{cursor:grabbing}.bottombar{display:flex;align-items:center;gap:14px;padding:0 18px;height:60px;background:#e2e8f0;border-top:1px solid #cbd5e1;flex-shrink:0}.tool-btn{display:flex;align-items:center;gap:8px;padding:8px 20px;background:#f1f5f9;border:2px solid #cbd5e1;border-radius:10px;font-size:14px;font-weight:600;color:#1e293b;cursor:pointer;transition:background .12s,border-color .12s;-webkit-user-select:none;user-select:none}.tool-btn:hover{background:#e2e8f0;border-color:#94a3b8}.tool-btn--active{background:#fef9c3;border-color:#f59e0b;color:#78350f}.tool-icon{font-size:18px;line-height:1}.tool-hint{font-size:12px;color:#64748b}