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14px}.quiz__actions{display:flex;gap:10px;flex-wrap:wrap}.quiz__next{width:auto;flex:1}.quiz__ainote{margin-top:12px;font-size:13px;color:var(--accent-2);text-align:center}.quiz__result{text-align:center;display:flex;flex-direction:column;align-items:center;gap:6px}.quiz__result .quiz__actions{margin-top:16px;justify-content:center}@media (max-width: 900px){.lessonnav{flex-direction:column}.lessonnav__btn:last-child{text-align:left}}.viz-loading{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:14px;min-height:320px;color:var(--muted);font-size:14px}.viz-loading__spinner{width:38px;height:38px;border-radius:50%;border:3px solid var(--border);border-top-color:var(--accent);animation:viz-spin .7s linear infinite}@keyframes viz-spin{to{transform:rotate(360deg)}}.planned{margin-top:40px;text-align:center;background:var(--panel);border:1px dashed var(--border);border-radius:16px;padding:50px 30px}.planned__icon{font-size:46px}.planned h2{margin:10px 0}.planned p{color:var(--muted);max-width:56ch;margin:8px auto;line-height:1.6}.planned__hint{font-size:14px}.link{background:none;border:none;color:var(--accent);cursor:pointer;padding:0;font:inherit}.sidebar__item{align-items:flex-start}.sidebar__dot{margin-top:6px}@media (max-width: 900px){.app{display:block}.topbar{display:flex;align-items:center;gap:12px;position:sticky;top:0;z-index:30;background:var(--panel);border-bottom:1px solid var(--border);padding:10px 14px;padding-top:max(10px,env(safe-area-inset-top))}.topbar__menu{background:var(--panel-2);border:1px solid var(--border);color:var(--text);width:38px;height:38px;border-radius:9px;font-size:18px;cursor:pointer;flex-shrink:0}.topbar__logo{width:30px;height:30px;display:grid;place-items:center;flex-shrink:0;background:linear-gradient(135deg,var(--accent),var(--accent-2));border-radius:8px;color:#0d1117;font-weight:800}.topbar__title{font-weight:600;font-size:15px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.sidebar{position:fixed;top:0;left:0;height:100dvh;width:min(86vw,320px);z-index:50;transform:translate(-100%);transition:transform .25s ease;box-shadow:0 0 40px #00000080;padding-top:max(20px,env(safe-area-inset-top));padding-bottom:max(20px,env(safe-area-inset-bottom));padding-left:max(14px,env(safe-area-inset-left))}.sidebar.is-open{transform:translate(0)}.sidebar__close{display:grid;place-items:center;margin-left:auto;width:32px;height:32px;border-radius:8px;background:var(--panel-2);border:1px solid var(--border);color:var(--text);cursor:pointer;font-size:14px}.content{max-width:none;padding:20px max(18px,env(safe-area-inset-right)) calc(64px + env(safe-area-inset-bottom)) max(18px,env(safe-area-inset-left))}.content__title{font-size:26px}.content__summary{font-size:15px}.viz__controls{gap:16px;padding:14px}.control{min-width:140px;flex:1}}@media (min-width: 901px){.scrim{display:none}}@media (min-width: 1000px){.content{max-width:min(94vw,1400px)}.mul__svg,.add__svg,.viz__stage svg,.ns__line{max-width:100%}.viz__stage{min-height:360px;padding:30px}.viz__intro{font-size:17px}}@media (min-width: 1400px){.content{max-width:min(92vw,1760px)}.viz__stage{min-height:460px}}@media (min-width: 2000px){.content{max-width:min(90vw,2200px)}.viz__stage{min-height:560px}}@media (pointer: coarse){.action,.lessonnav__test,.lessonnav__btn,.segmented__btn,.quiz__option,.modal__btn,.tutor__chip{min-height:44px}.control{min-width:200px}}