/* Stable objects move only when the mathematical operation changes. */
.ns-activity{color:#122c44;width:100%;max-width:1100px;margin-inline:auto}
.ns-activity header h1{font-size:clamp(18px,2.2vw,25px);margin:3px 0}
.ns-story{font-size:clamp(17px,2vw,23px);font-weight:750;margin:6px 0;padding:7px 10px;border-right:5px solid #075bb6;background:#fff4d1}
.ns-board{padding:4px;border:2px solid #26465e;background:#fff}
.ns-caption{margin:3px 0 5px;text-align:center;font-size:clamp(16px,1.8vw,22px);font-weight:800;min-height:1.6em;color:#073b73}
.ns-scene svg{display:block;width:100%;height:auto;max-height:43svh;margin:auto;overflow:visible;touch-action:pan-y}
.ns-tray,.ns-second-tray{fill:#fff8dc;stroke:#624319;stroke-width:3;transition:x 850ms ease,width 850ms ease,opacity 400ms ease}
.ns-group-label,.ns-other-label,.ns-counted{font-size:22px;font-weight:800;fill:#17384c}
.ns-scene [data-ns-object]{cursor:pointer;transition:transform 950ms ease;outline:none}
.ns-count-ring,.ns-count-check{opacity:0}
.ns-selected .ns-count-ring{opacity:1;stroke:#075bb6;stroke-dasharray:5 3}
.ns-counted-object .ns-count-ring,.ns-counted-object .ns-count-check{opacity:1}
.ns-scene [data-ns-object]:focus .ns-count-ring{opacity:1;stroke:#075bb6;stroke-width:5}
.ns-writing{display:flex;gap:6px;align-items:stretch;justify-content:center;min-height:98px}
.ns-writing>div{border:2px solid #075bb6;padding:4px 8px;text-align:center;display:flex;flex-direction:column;justify-content:center}
.ns-writing strong{font-size:16px;color:#073b73}
.ns-writing .ns-value{border-color:#965000;min-width:90px}
.ns-writing .ns-sentence{border-color:#7131a5}
.ns-value>b{font-size:34px;font-weight:900;color:#9b1839}
.ns-math{display:inline-flex;direction:rtl;align-items:center;justify-content:center;gap:.24em;font-size:clamp(24px,3.6vw,38px);font-weight:900;white-space:nowrap}
.ns-number{color:#073b73}.ns-symbol{color:#a6113b}
.ns-navigation{display:flex;align-items:center;justify-content:center;gap:6px;flex-wrap:wrap;margin:6px 0}
.ns-activity button{border:2px solid #075bb6;background:#fff;color:#073b73;font-weight:800;cursor:pointer;padding:7px 13px;min-height:38px;box-shadow:0 2px 0 #075bb6}
.ns-activity button:hover:not(:disabled){background:#dcefff}
.ns-activity button:focus-visible{outline:3px solid #a6113b;outline-offset:3px}
.ns-activity button:disabled{background:#e8edf0;color:#62707c;border-color:#a4b0b9;box-shadow:none;cursor:default;opacity:.65}
.ns-activity [data-ns-next],.ns-activity [data-ns-auto]{background:#075bb6;color:white}
.ns-navigation [data-ns-progress]{font-size:15px;min-width:45px;text-align:center}
.ns-question{border:3px solid #9b5100;background:#fff6d5;padding:10px;margin:6px 0}
.ns-question-heading{display:flex;align-items:center;justify-content:space-between;color:#733800}
.ns-question h2{font-size:20px;margin:5px 0}
.ns-stem{text-align:center;margin:6px 0}
.ns-choices{display:flex;flex-wrap:wrap;gap:8px;justify-content:center}
.ns-choices button{flex:1 1 140px;min-height:55px;max-width:360px;border-radius:0}
.ns-choices .ns-math{font-size:clamp(23px,3vw,32px)}
.ns-choices .ns-correct{background:#006b38!important;color:white;border-color:#003f22}
.ns-correct .ns-number,.ns-correct .ns-symbol{color:white}
.ns-choices .ns-incorrect{border:3px solid #a6113b;background:#ffe1e7}
.ns-feedback{font-weight:800;min-height:1.6em;margin:5px 0;color:#17384c}
.ns-options{display:flex;flex-wrap:wrap;gap:14px;padding:12px}
.ns-options label{display:flex;align-items:center;gap:8px;font-weight:800}
.ns-options select{padding:7px;border:2px solid #075bb6;max-width:100%}
.ns-activity [hidden]{display:none!important}
.mv-experience:not(.mv-focus) .ns-activity .ns-scene svg.mv-diagram{max-height:43svh!important}
.mv-experience:not(.mv-focus) .ns-asking .ns-scene svg.mv-diagram{max-height:27svh!important}
.ns-asking .ns-caption{display:none}
@media(max-width:600px){.ns-writing{flex-wrap:wrap;min-height:130px}.ns-writing>div{padding:3px 6px}.ns-writing .ns-sentence{flex-basis:90%}.ns-scene svg{min-height:160px}.ns-story{font-size:16px}.ns-navigation{gap:4px}.ns-navigation button{padding:5px 10px}.ns-question h2{font-size:18px}.ns-choices button{flex-basis:42%}.ns-options label{flex-wrap:wrap}}
@media(prefers-reduced-motion:reduce){.ns-scene [data-ns-object],.ns-tray,.ns-second-tray{transition:none}}