:root{--color-bg:#fdfaf5;--color-text:#1a1a1a;--color-accent:#2b6f5c;--color-accent-contrast:#fff;--color-token:#d9862c;--color-border:#c8c0b4;--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light}*{box-sizing:border-box}body{background:var(--color-bg);color:var(--color-text);margin:0;font-family:Atkinson Hyperlegible,Segoe UI,system-ui,sans-serif}.app,.app-loading{flex-direction:column;align-items:center;gap:1rem;min-height:100vh;padding:1.5rem;display:flex}.status-banner{background:#eee;border-radius:.5rem;padding:.5rem 1rem;font-size:1rem}.status-banner--error{color:#58151c;background:#f8d7da}.accessibility-controls{align-self:flex-end;gap:1rem;font-size:.95rem;display:flex}.toggle{cursor:pointer;align-items:center;gap:.4rem;display:flex}.main-menu{text-align:center;max-width:32rem}.main-menu h1{margin-bottom:.25rem;font-size:2rem}.main-menu__options{flex-wrap:wrap;justify-content:center;gap:1.5rem;margin-top:1.5rem;display:flex}.menu-option{border:3px solid var(--color-border);cursor:pointer;background:#fff;border-radius:1rem;flex-direction:column;align-items:center;gap:.4rem;min-width:12rem;padding:1.5rem 2rem;font-size:1.1rem;display:flex}.menu-option:focus-visible,.step-button:focus-visible,.primary-button:focus-visible,.link-button:focus-visible{outline-offset:2px;outline:3px solid #1a5fb4}.menu-option__title{color:var(--color-accent);font-size:1.4rem;font-weight:700}.game-screen{flex-direction:column;align-items:center;gap:1.5rem;width:100%;max-width:40rem;display:flex}.game-screen__header{justify-content:space-between;align-items:center;width:100%;display:flex}.link-button{color:var(--color-accent);cursor:pointer;background:0 0;border:none;font-size:1rem;text-decoration:underline}.number-line{width:100%;padding:4.5rem 1rem 1rem}.number-line__track{border-top:4px solid var(--color-text);min-height:2.5rem;padding-top:.5rem;position:relative}.number-line__arcs{pointer-events:none;width:100%;height:3.4rem;position:absolute;bottom:100%;left:0;right:0;overflow:visible}.number-line__arc{stroke-width:3px;fill:none;transform-origin:bottom;animation:.35s ease-out number-line-arc-in}.number-line__arcs--instant .number-line__arc{animation:none}.number-line__arc--right{stroke:var(--color-accent)}.number-line__arc--left{stroke:#9a4b1f}@keyframes number-line-arc-in{0%{opacity:0;transform:scaleY(.3)}to{opacity:1;transform:scaleY(1)}}.number-line__arc-label{white-space:nowrap;font-size:.85rem;font-weight:700;position:absolute;top:-2.55rem;transform:translate(-50%)}.number-line__arc-label--right{color:var(--color-accent)}.number-line__arc-label--left{color:#9a4b1f}.number-line__tick{flex-direction:column;align-items:center;gap:.25rem;display:flex;position:absolute;top:0;transform:translate(-50%)}.number-line__tick-mark{background:var(--color-text);width:2px;height:.75rem;margin-top:-.85rem}.number-line__tick-label{font-size:1.1rem;font-weight:600}.number-line__token{background:var(--color-token);clip-path:polygon(0% 0%,100% 0%,50% 100%);width:1.7rem;height:1.4rem;transition:left .5s ease-in-out;position:absolute;top:-1.4rem;transform:translate(-50%)}.number-line__token--instant{transition:none}.number-line__direction{font-size:.95rem;line-height:1;position:absolute;top:-.95rem;left:50%;transform:translate(-50%)}.number-line__direction--right{color:var(--color-accent)}.number-line__direction--left{color:#9a4b1f}.position-indicator{margin:0;font-size:1.05rem;font-weight:600}.step-button{background:var(--color-accent);color:var(--color-accent-contrast);cursor:pointer;border:none;border-radius:1rem;padding:.9rem 1.75rem;font-size:1.7rem;font-weight:700}.step-button--left{background:#9a4b1f}.step-button:disabled{opacity:.5;cursor:not-allowed}.game-screen__controls{align-items:center;gap:1rem;display:flex}.game-screen__submit{justify-content:center;margin-top:1.5rem;display:flex}.submit-button{border:2px solid var(--color-accent);color:var(--color-accent);cursor:pointer;background:#fff;border-radius:1rem;padding:.9rem 1.75rem;font-size:1.3rem;font-weight:700}.submit-button:focus-visible{outline-offset:2px;outline:3px solid #1a5fb4}.challenge-equation{margin:0;font-size:2rem;font-weight:700}.progress-bar{flex-direction:column;align-items:center;gap:.4rem;width:100%;display:flex}.progress-bar__segments{gap:.35rem;display:flex}.progress-bar__segment{border:1px solid var(--color-border);background:#e6e0d4;border-radius:.25rem;width:1.5rem;height:.75rem}.progress-bar__segment--filled{background:var(--color-accent);border-color:var(--color-accent)}.progress-bar__label{font-size:.95rem;font-weight:600}.feedback{margin:0;font-size:1.2rem;font-weight:700}.feedback--correct{color:var(--color-accent)}.feedback--incorrect{color:#9a4b1f}.celebration{text-align:center;border:2px solid var(--color-token);background:#fff7e0;border-radius:1rem;padding:1rem 1.5rem}.celebration__message{margin:0 0 .75rem;font-size:1.3rem;font-weight:700}.celebration__actions{justify-content:center;gap:1rem;display:flex}.primary-button{background:var(--color-accent);color:var(--color-accent-contrast);cursor:pointer;border:none;border-radius:.6rem;padding:.6rem 1.2rem;font-size:1rem}@media (prefers-contrast:more){:root{--color-border:#000}}