.sr{clip-path:inset(50%);white-space:nowrap;width:1px;height:1px;position:absolute;overflow:hidden}.top{border-bottom:1.5px solid var(--ink);view-transition-name:chapter-top;grid-template-columns:auto minmax(0,1fr);align-items:center;gap:8px 28px;padding:12px 24px 10px;display:grid}.top nav{grid-area:2/1/auto/-1;min-width:0}@media (prefers-reduced-motion:no-preference){@view-transition{navigation:auto}}.brand{align-items:center;gap:8px;margin:0;font-size:14px;font-weight:800;display:inline-flex}.brand a{align-items:center;gap:8px;text-decoration:none;display:inline-flex}.brand span{color:var(--muted);font-weight:400}.credit{color:var(--muted);margin:0 0 0 auto;font-size:11.5px}.credit a{color:var(--ink)}.top ol{scrollbar-width:none;flex-wrap:nowrap;gap:6px;margin:0;padding:2px 4px 4px 0;list-style:none;display:flex;position:relative;overflow-x:auto}.top ol::-webkit-scrollbar{display:none}.top nav li{flex:none}.top nav a{color:var(--muted);border:1.5px solid #0000;border-radius:999px;align-items:center;gap:6px;padding:4px 10px;font-size:12.5px;text-decoration:none;display:inline-flex}.top nav a:hover{border-color:var(--rule)}.top nav .num{font-weight:800}.top nav .num:before{content:"";width:1.1em;display:inline-block}.top nav a[data-mark=current]{border-color:var(--ink);background:var(--card);color:var(--ink);box-shadow:2px 2px 0 var(--ink)}.top nav a[data-mark=done]{color:var(--ink)}.top nav a[data-mark=done] .num:before{content:"✓";color:var(--ok)}.top nav a[data-mark=skipped] .num:before{content:"↷";color:var(--warn)}.top nav a[data-mark=current] .num:before{display:none}main{padding:16px 24px 32px}.eyebrow{letter-spacing:.1em;text-transform:uppercase;color:var(--muted);margin:0;font-size:11px}.chapter{grid-template-columns:minmax(0,1.75fr) minmax(340px,1fr);align-items:start;gap:24px;display:grid}.stage{border:1.5px solid var(--rule);border-radius:16px;flex-direction:column;justify-content:center;align-items:center;padding:16px;display:flex}.stage figure{width:100%;margin:0}.stage figcaption{text-align:center;color:var(--muted);margin-top:8px;font-size:13px}.side{flex-direction:column;gap:16px;display:flex}@media (width>=861px){body{flex-direction:column;height:100dvh;display:flex;overflow:hidden}main{flex:1;min-height:0;padding-bottom:16px}.chapter{height:100%}.stage{height:100%;overflow:auto}:where(.stage) svg{max-height:calc(100dvh - 220px)}.side{scrollbar-gutter:stable;height:100%;padding:2px 10px 24px 2px;overflow-y:auto}}.intro{flex-direction:column;gap:10px;font-size:14px;line-height:1.55;display:flex}.intro h1{margin:0;font-size:22px;font-weight:800;line-height:1.25}.intro p{margin:0}.intro .story{font-size:15px}.intro .goal{border-left:3px solid var(--acc);padding:2px 0 2px 10px}.intro .lbl{letter-spacing:.1em;text-transform:uppercase;color:var(--muted);margin:0;font-size:11px}.intro ul{flex-direction:column;gap:4px;margin:4px 0 0;padding-left:18px;display:flex}.intro .terms summary{cursor:pointer;font-weight:700}.intro dl{flex-direction:column;gap:8px;margin:8px 0 0;display:flex}.intro dt{font-weight:800}.intro dd{color:var(--ink);margin:0}.intro .how{color:var(--muted);font-size:13px}.intro .resume{align-self:flex-start}.log{border-top:1.5px dashed var(--rule);color:var(--muted);flex-direction:column;gap:10px;margin:0;padding:12px 0 0;font-size:13.5px;line-height:1.5;list-style:none;display:flex}.log li{padding-left:22px;position:relative}.log li:before{content:"✓";color:var(--ok);font-weight:800;position:absolute;left:0}.card{background:var(--card);border:1.5px solid var(--ink);box-shadow:3px 3px 0 var(--ink);border-radius:14px;flex-direction:column;gap:14px;padding:18px;display:flex}.card .count{letter-spacing:.1em;text-transform:uppercase;color:var(--muted);margin:0;font-size:11px}.card .narration{margin:4px 0 0;font-size:16px;font-weight:700;line-height:1.45}.card .hint{border-left:3px solid var(--acc);margin:0;padding:2px 0 2px 10px;font-size:13px}.recover{border-top:1px dashed var(--rule);flex-wrap:wrap;gap:8px;padding-top:12px;display:flex}.recover .chip{box-shadow:none;border-color:var(--rule);font-size:12px}.recover .chip:disabled{opacity:.4;cursor:default}.opts{flex-wrap:wrap;gap:8px;display:flex}.chip{font:inherit;color:var(--ink);background:var(--card);border:1.5px solid var(--ink);cursor:pointer;box-shadow:2px 2px 0 var(--ink);border-radius:8px;padding:6px 12px;font-size:13px}.chip[aria-pressed=true],.chip[aria-checked=true]{background:var(--ink);color:var(--paper);box-shadow:none}.big{background:var(--acc);border:1.5px solid var(--ink);box-shadow:3px 3px 0 var(--ink);border-radius:999px;align-self:flex-start;padding:8px 16px;font-size:14px;font-weight:800;text-decoration:none}.quiz{border:0;flex-direction:column;gap:10px;margin:0;padding:0;display:flex}.quiz legend{margin-bottom:8px;padding:0;font-size:14px}.quiz .opts{flex-direction:column;align-items:stretch}.quiz .chip{text-align:left}.feedback p{margin:6px 0 0;font-size:13px}.feedback summary{cursor:pointer;margin-top:8px;font-size:13px}.feedback ul,.tips ul,.closing ul{flex-direction:column;gap:6px;margin:6px 0 0;padding-left:18px;font-size:13px;display:flex}.challenge{flex-direction:column;gap:12px;display:flex}.challenge .count{gap:10px;display:flex}.challenge .count [data-current]{color:var(--ink);font-weight:800}.challenge .count [data-solved]{color:var(--ok)}.challenge .chip[data-wrong]{background:var(--card);color:var(--muted);border-color:var(--rule);box-shadow:none;text-decoration:line-through}.challenge .chip:disabled:not([data-wrong]){opacity:.5;box-shadow:none}.tips .lbl{letter-spacing:.1em;text-transform:uppercase;color:var(--muted);margin:0;font-size:11px}.closing{border-top:1px dashed var(--rule);padding-top:12px}.closing h2{margin:0;font-size:16px}.closing p{margin:6px 0 0;font-size:13px}.closing a{white-space:nowrap;margin-left:6px}.stamp{letter-spacing:.14em;border:2px solid;border-radius:6px;padding:1px 7px;font-size:11px;font-weight:900;display:inline-block;transform:rotate(-2deg)}.stamp.correct{color:var(--ok)}.stamp.wrong{color:var(--bad)}.stamp.neutral{color:var(--ink)}.quiz .chip[aria-disabled=true]{opacity:.5;box-shadow:none;cursor:default}.feedback:focus{outline:none}.drawer{background:var(--card);border:1.5px solid var(--ink);border-radius:14px;padding:14px 18px;font-size:13.5px}.drawer header{justify-content:space-between;align-items:center;gap:8px;display:flex}.drawer h2{letter-spacing:.1em;text-transform:uppercase;color:var(--muted);margin:0;font-size:11px}.drawer .chip{box-shadow:none;padding:2px 9px}@media (width<=860px){.top{grid-template-columns:minmax(0,1fr);gap:6px;padding:12px 16px 8px}.credit{grid-row:3;margin:0}.top nav a:not([data-mark=current]) .name{display:none}main{padding:12px 16px 24px}.chapter{grid-template-columns:minmax(0,1fr);gap:16px}.stage{min-height:0;padding:8px}.drawer{scroll-margin-top:12px}.drawer.sheet{z-index:20;max-height:62dvh;box-shadow:0 -4px 0 var(--ink);border-bottom:0;border-radius:14px 14px 0 0;position:fixed;bottom:0;left:0;right:0;overflow-y:auto}.drawer.sheet header{background:var(--card);padding:4px 0;position:sticky;top:-14px}}
