.crumbs[data-astro-cid-ivjjushy] a[data-astro-cid-ivjjushy]{color:var(--ink-2);font-weight:600;text-decoration:none}.shell[data-astro-cid-ivjjushy]{grid-template-columns:250px minmax(0,1fr) 210px;gap:48px;max-width:1360px;margin:0 auto;padding:32px 24px 96px;display:grid}.side[data-astro-cid-ivjjushy],.toc[data-astro-cid-ivjjushy]{max-height:calc(100vh - 96px);font-family:var(--sans);align-self:start;font-size:.85rem;position:sticky;top:76px;overflow:auto}.side[data-astro-cid-ivjjushy] ol[data-astro-cid-ivjjushy],.toc[data-astro-cid-ivjjushy] ol[data-astro-cid-ivjjushy]{gap:2px;margin:12px 0 0;padding:0;list-style:none;display:grid}.side[data-astro-cid-ivjjushy] li[data-astro-cid-ivjjushy]>a[data-astro-cid-ivjjushy],.side[data-astro-cid-ivjjushy] li[data-astro-cid-ivjjushy]>span[data-astro-cid-ivjjushy]{color:var(--ink-2);border-radius:6px;gap:10px;padding:6px 8px;line-height:1.35;text-decoration:none;display:flex}.side[data-astro-cid-ivjjushy] li[data-astro-cid-ivjjushy]>a[data-astro-cid-ivjjushy]:hover{background:var(--sunk)}.side[data-astro-cid-ivjjushy] li[data-astro-cid-ivjjushy].here>a[data-astro-cid-ivjjushy]{background:var(--accent-soft);color:var(--ink);font-weight:600}.side[data-astro-cid-ivjjushy] li[data-astro-cid-ivjjushy].soon>span[data-astro-cid-ivjjushy]{color:var(--muted);opacity:.7}.side[data-astro-cid-ivjjushy] .n[data-astro-cid-ivjjushy]{color:var(--muted);min-width:1.4em;padding-top:1px;font-size:.78rem}.toc[data-astro-cid-ivjjushy] a[data-astro-cid-ivjjushy]{border-left:2px solid var(--rule);color:var(--muted);padding:4px 0 4px 12px;line-height:1.35;text-decoration:none;display:block}.toc[data-astro-cid-ivjjushy] a[data-astro-cid-ivjjushy].on{color:var(--ink);border-color:var(--accent);font-weight:600}.toc[data-astro-cid-ivjjushy] a[data-astro-cid-ivjjushy]{position:relative}.toc[data-astro-cid-ivjjushy] a[data-astro-cid-ivjjushy].done{color:var(--good);padding-right:18px}.toc[data-astro-cid-ivjjushy] a[data-astro-cid-ivjjushy].done:after{content:"✓";font-weight:700;position:absolute;top:4px;right:0}.toc[data-astro-cid-ivjjushy] a[data-astro-cid-ivjjushy].pop:after{animation:.6s cubic-bezier(.2,.9,.3,1.6) tick-pop}@keyframes tick-pop{0%{transform:scale(0)}60%{transform:scale(1.7)}to{transform:scale(1)}}.cp-count[data-astro-cid-ivjjushy]{color:var(--muted);margin-top:10px;font-size:.78rem}.cp-count[data-astro-cid-ivjjushy] .num[data-astro-cid-ivjjushy]{color:var(--ink);font-weight:600}.sheet-link[data-astro-cid-ivjjushy]{margin-top:14px;font-size:.8rem;font-weight:600;text-decoration:none;display:inline-block}.toast[data-astro-cid-ivjjushy]{left:50%;bottom:calc(24px + env(safe-area-inset-bottom,0px));opacity:0;z-index:40;background:var(--ink);min-width:240px;max-width:calc(100vw - 32px);color:var(--paper);font:.88rem/1.35 var(--sans);border-radius:12px;gap:2px;padding:12px 18px 12px 48px;transition:transform .35s cubic-bezier(.2,.9,.3,1.2),opacity .3s;display:grid;position:fixed;transform:translate(-50%,20px);box-shadow:0 10px 30px #00000040}.toast[data-astro-cid-ivjjushy]:before{content:"✓";background:var(--good);width:22px;height:22px;color:var(--paper);border-radius:50%;place-items:center;font-size:.8rem;font-weight:800;display:grid;position:absolute;top:50%;left:14px;translate:0 -50%}.toast[data-astro-cid-ivjjushy].in{opacity:1;transform:translate(-50%)}.toast[data-astro-cid-ivjjushy].out{opacity:0;transform:translate(-50%,10px)}.toast[data-astro-cid-ivjjushy] span{opacity:.75}.finale[data-astro-cid-ivjjushy]{z-index:50;background:color-mix(in srgb, var(--paper) 55%, transparent);backdrop-filter:blur(6px);opacity:0;place-items:center;padding:16px;transition:opacity .25s;display:grid;position:fixed;inset:0}.finale[data-astro-cid-ivjjushy].open{opacity:1}#confetti[data-astro-cid-ivjjushy]{pointer-events:none;width:100%;height:100%;position:fixed;inset:0}.finale-card[data-astro-cid-ivjjushy]{background:var(--surface);border:1px solid var(--rule);text-align:center;width:min(520px,100%);font-family:var(--sans);border-radius:18px;padding:28px;transition:transform .45s cubic-bezier(.2,.9,.3,1.2);position:relative;transform:translateY(18px)scale(.97);box-shadow:0 24px 60px #00000038}.finale[data-astro-cid-ivjjushy].open .finale-card[data-astro-cid-ivjjushy]{transform:none}.finale-seal[data-astro-cid-ivjjushy]{place-items:center;margin-bottom:10px;display:grid}.finale-seal[data-astro-cid-ivjjushy] .tick[data-astro-cid-ivjjushy]{stroke-dasharray:48;stroke-dashoffset:48px}.finale[data-astro-cid-ivjjushy].open .tick[data-astro-cid-ivjjushy]{animation:.6s ease-out .25s forwards draw}@keyframes draw{to{stroke-dashoffset:0}}.finale-card[data-astro-cid-ivjjushy] h2[data-astro-cid-ivjjushy]{margin:8px 0 18px;font-size:1.35rem}.finale-stats[data-astro-cid-ivjjushy]{grid-template-columns:repeat(3,1fr);gap:8px;display:grid}.finale-stats[data-astro-cid-ivjjushy] div[data-astro-cid-ivjjushy]{background:var(--sunk);border-radius:10px;gap:2px;padding:12px 6px;display:grid}.finale-stats[data-astro-cid-ivjjushy] b[data-astro-cid-ivjjushy]{color:var(--accent);font-size:1.5rem}.finale-stats[data-astro-cid-ivjjushy] span[data-astro-cid-ivjjushy]{color:var(--muted);font-size:.74rem;line-height:1.3}.finale-note[data-astro-cid-ivjjushy]{color:var(--ink-2);margin:16px auto;font-size:.92rem}.finale-actions[data-astro-cid-ivjjushy]{flex-wrap:wrap;justify-content:center;gap:8px;display:flex}.finale-actions[data-astro-cid-ivjjushy] a[data-astro-cid-ivjjushy]{text-decoration:none}.bar[data-astro-cid-ivjjushy]{background:var(--rule);border-radius:2px;height:3px;margin-top:16px;overflow:hidden}.bar[data-astro-cid-ivjjushy] i[data-astro-cid-ivjjushy]{background:var(--accent);width:0;height:100%;display:block}.lesson[data-astro-cid-ivjjushy]{min-width:0;max-width:820px}.lesson-head[data-astro-cid-ivjjushy]{padding-bottom:8px}.dek[data-astro-cid-ivjjushy]{color:var(--ink-2);margin:0 0 1.4em;font-size:1.2rem}.goals[data-astro-cid-ivjjushy]{border:1px solid var(--rule);background:var(--surface);border-radius:var(--radius);font-family:var(--sans);padding:14px 18px;font-size:.92rem}.goals[data-astro-cid-ivjjushy] ul[data-astro-cid-ivjjushy]{gap:4px;margin:8px 0 0;padding-left:1.2em;display:grid}.lesson-foot[data-astro-cid-ivjjushy]{border-top:1px solid var(--rule);flex-wrap:wrap;gap:10px;margin-top:4em;padding-top:2em;display:flex}.lesson-foot[data-astro-cid-ivjjushy] .btn[data-astro-cid-ivjjushy]{text-decoration:none}@media (width<=1180px){.shell[data-astro-cid-ivjjushy]{grid-template-columns:220px minmax(0,1fr)}.toc[data-astro-cid-ivjjushy]{display:none}}@media (width<=860px){.shell[data-astro-cid-ivjjushy]{grid-template-columns:1fr;gap:0;padding:20px 16px 72px}.side[data-astro-cid-ivjjushy]{display:none}}.callout[data-astro-cid-q2ml7llr]{border-radius:0 var(--radius) var(--radius) 0;border-left:3px solid var(--c);background:var(--bg);max-width:var(--measure);margin:1.6em 0;padding:14px 18px}.callout-key[data-astro-cid-q2ml7llr]{--c:var(--accent);--bg:var(--accent-soft)}.callout-trap[data-astro-cid-q2ml7llr]{--c:var(--bad);--bg:var(--bad-soft)}.callout-def[data-astro-cid-q2ml7llr]{--c:var(--ink-2);--bg:var(--sunk)}.callout-intuition[data-astro-cid-q2ml7llr]{--c:var(--gold);--bg:var(--gold-soft)}.eyebrow[data-astro-cid-q2ml7llr]{color:var(--c)}.callout-title[data-astro-cid-q2ml7llr]{color:var(--ink-2);letter-spacing:.04em}.callout-body[data-astro-cid-q2ml7llr] p{margin:.4em 0 0}.callout-body[data-astro-cid-q2ml7llr] p:first-child{margin-top:.3em}.formula[data-astro-cid-ggshasbz]{border:1px solid color-mix(in srgb, var(--accent) 35%, var(--rule));border-radius:var(--radius);background:linear-gradient(var(--surface), var(--surface)) padding-box, var(--surface);max-width:100%;font-family:var(--sans);margin:1.8em 0;padding:0;overflow:hidden}figcaption[data-astro-cid-ggshasbz]{background:var(--accent-soft);border-bottom:1px solid color-mix(in srgb, var(--accent) 25%, var(--rule));flex-wrap:wrap;align-items:center;gap:10px;padding:10px 16px;display:flex}.f-name[data-astro-cid-ggshasbz]{color:var(--ink);font-size:.92rem;font-weight:700}.f-tag[data-astro-cid-ggshasbz]{font:600 .68rem var(--sans);letter-spacing:.08em;text-transform:uppercase;color:var(--accent);border:1px solid;border-radius:999px;padding:1px 7px}.f-sheet[data-astro-cid-ggshasbz]{margin-left:auto;font-size:.78rem;font-weight:600;text-decoration:none}.f-eq[data-astro-cid-ggshasbz]{padding:10px 16px;font-size:1.12rem}.f-eq[data-astro-cid-ggshasbz] .katex-display{margin:.5em 0}.f-legend[data-astro-cid-ggshasbz]{border-top:1px dashed var(--rule);grid-template-columns:auto 1fr;gap:6px 14px;margin:0;padding:12px 16px;font-size:.86rem;display:grid}.f-legend[data-astro-cid-ggshasbz] dt[data-astro-cid-ggshasbz]{text-align:right}.f-legend[data-astro-cid-ggshasbz] dd[data-astro-cid-ggshasbz]{color:var(--ink-2);margin:0}.f-use[data-astro-cid-ggshasbz]{border-top:1px dashed var(--rule);color:var(--ink-2);max-width:none;margin:0;padding:10px 16px;font-size:.86rem}.f-use[data-astro-cid-ggshasbz] span[data-astro-cid-ggshasbz]{color:var(--ink);margin-right:4px;font-weight:700}.check-q{margin:0 0 12px;font-size:1rem;font-weight:550}.check-opts{gap:8px;display:grid}.check-opt{text-align:left;background:var(--surface);width:100%;color:var(--ink);border:1px solid var(--rule);cursor:pointer;font:inherit;border-radius:8px;align-items:flex-start;gap:12px;padding:10px 12px;transition:border-color .15s,background .15s;display:flex}.check-opt:hover:not(:disabled){border-color:var(--accent)}.check-opt:disabled{opacity:.45;cursor:default}.check-opt.right{border-color:var(--good);background:var(--good-soft);opacity:1}.check-opt.wrong{border-color:var(--bad);background:var(--bad-soft)}.check-key{font:600 .75rem var(--mono);color:var(--muted);border:1px solid var(--rule);border-radius:4px;flex:none;margin-top:2px;padding:1px 6px}.check-why{border-left:3px solid;border-radius:8px;margin-top:12px;padding:10px 14px}.check-why.right{background:var(--good-soft);border-color:var(--good)}.check-why.wrong{background:var(--bad-soft);border-color:var(--bad)}.check-retry{color:var(--muted)}.check-badge{font:600 .75rem var(--sans);color:var(--good);background:var(--good-soft);border-radius:999px;padding:2px 8px}.check.is-solved{border-color:color-mix(in srgb, var(--good) 40%, var(--rule))}.numeric-row{flex-wrap:wrap;align-items:center;gap:8px;display:flex}.numeric-row input{font:500 1rem var(--mono);border:1px solid var(--rule);background:var(--paper);width:9em;color:var(--ink);border-radius:8px;padding:8px 10px}.reveal{background:var(--sunk);border-radius:8px;margin-top:12px;padding:12px 14px}.reveal ol{margin:6px 0 0;padding-left:1.3em}.reveal li{margin:6px 0}.check{transition:border-color .3s}.just-solved{animation:.6s cubic-bezier(.2,.9,.3,1.3) solved-lift}.just-solved .check-badge{animation:.45s cubic-bezier(.2,.9,.3,1.4) badge-in}@keyframes solved-lift{0%{box-shadow:0 0 0 0 color-mix(in srgb, var(--good) 45%, transparent);transform:none}35%{transform:translateY(-3px)}to{transform:none;box-shadow:0 0 0 10px #0000}}@keyframes badge-in{0%{opacity:0;transform:scale(.4)}to{opacity:1;transform:none}}.fc:focus{outline:none}.fc-card{text-align:center;cursor:pointer;width:100%;min-height:180px;font:500 1.1rem/1.45 var(--serif);background:var(--paper);color:var(--ink);border:1px solid var(--rule);border-radius:10px;align-content:center;place-items:center;gap:14px;padding:28px 20px;display:grid}.fc-card:hover{border-color:var(--accent)}.fc-back{color:var(--accent);border-top:1px solid var(--rule);width:100%;max-width:46ch;padding-top:14px;font-weight:600}.fc-hint{font:.8rem var(--sans);color:var(--muted)}.fc-row{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:10px;min-height:40px;margin-top:12px;display:flex}.fc-left{color:var(--muted);font-size:.82rem}.fc-grades{flex-wrap:wrap;gap:6px;display:flex}.fc-grades kbd{font:.7rem var(--mono);color:var(--muted);margin-left:4px}.fc-g0{color:var(--bad)}.fc-g2{color:var(--good)}.fc-done p{margin:0 0 12px}