:root{--bg:#faf9f7;--panel:#fff;--ink:#1a1c20;--muted:#6b7280;--line:#e3e1dc;--accent:#c2410c;--accent-soft:#ffedd5;--cell-bg:#fff;--cell-line:#94a3b8;--style-active:#f59e0b;--style-active-bg:#fef3c7;--style-compare:#3b82f6;--style-compare-bg:#dbeafe;--style-done:#64748b;--style-done-bg:#e2e8f0;--style-reject:#dc2626;--style-reject-bg:#fee2e2;--style-found:#16a34a;--style-found-bg:#dcfce7;--code-bg:#fff;--hl-line:#fff3c4}@media (prefers-color-scheme:dark){:root{--bg:#111317;--panel:#191c22;--ink:#e5e7eb;--muted:#9ca3af;--line:#2a2e37;--accent:#fb923c;--accent-soft:#43200b;--cell-bg:#1f242c;--cell-line:#4b5563;--style-active-bg:#453510;--style-compare-bg:#172a54;--style-done-bg:#262d3a;--style-reject-bg:#481318;--style-found-bg:#12341d;--code-bg:#0d1117;--hl-line:#3b3416}.shiki,.shiki span{color:var(--shiki-dark)!important;background-color:#0000!important}.code-box .shiki{background-color:var(--code-bg)!important}}*{box-sizing:border-box}body{background:var(--bg);color:var(--ink);margin:0;font:15px/1.55 -apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif}a{color:var(--accent);text-decoration:none}a:hover{text-decoration:underline}h1{margin:8px 0 6px;font-size:26px}h2{margin:22px 0 8px;font-size:19px}.muted{color:var(--muted)}.err{color:var(--style-reject)}.app{max-width:1180px;margin:0 auto;padding:0 16px 60px}.topbar{border-bottom:1px solid var(--line);align-items:center;gap:24px;margin-bottom:18px;padding:14px 2px;display:flex}.brand{color:var(--ink);letter-spacing:-.5px;font-size:20px;font-weight:800}.brand span{color:var(--accent)}.topbar nav a{color:var(--muted);margin-right:14px}.topbar nav a.on{color:var(--ink);font-weight:600}.crumbs{color:var(--muted);margin:2px 0 0;font-size:13px}.tier-head{color:var(--muted);text-transform:uppercase;letter-spacing:.06em;margin-top:28px;font-size:14px}.pattern-grid{grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:12px;display:grid}.pattern-card{background:var(--panel);border:1px solid var(--line);color:var(--ink);border-radius:12px;padding:14px;display:block}.pattern-card:hover{border-color:var(--accent);text-decoration:none}.pattern-card.soon{opacity:.45;pointer-events:none}.pattern-title{font-weight:700}.pattern-summary{color:var(--muted);margin:4px 0 8px;font-size:13px}.pattern-meta{color:var(--accent);font-size:12px}.problem-list{padding-left:20px}.problem-list li{margin:8px 0}.problem-list li.soon{opacity:.5}.prob-link{margin-right:8px;font-weight:600}.axis{color:var(--muted);margin-left:8px;font-size:13px}.soon-tag{color:var(--muted);border:1px solid var(--line);border-radius:6px;margin-left:8px;padding:1px 6px;font-size:11px}.diff{text-transform:uppercase;border-radius:6px;padding:2px 7px;font-size:11px;font-weight:700}.diff-easy{background:var(--style-found-bg);color:var(--style-found)}.diff-medium{background:var(--style-active-bg);color:var(--style-active)}.diff-hard{background:var(--style-reject-bg);color:var(--style-reject)}.prob-head{flex-wrap:wrap;align-items:baseline;gap:12px;display:flex}.canonical{color:var(--muted);font-size:13px}.tabbar{border-bottom:1px solid var(--line);flex-wrap:wrap;gap:4px;margin:14px 0;display:flex}.tab{color:var(--muted);cursor:pointer;background:0 0;border:none;border-bottom:2px solid #0000;padding:8px 14px;font-size:14px}.tab.on{color:var(--ink);border-bottom-color:var(--accent);font-weight:600}.tab.copy{margin-left:auto}.btn{background:var(--accent);color:#fff;cursor:pointer;border:none;border-radius:8px;padding:8px 14px;font-size:14px}.hints{background:var(--panel);border:1px solid var(--line);border-radius:12px;margin-top:18px;padding:12px 16px}.hint-item{margin:8px 0}.solution-split{grid-template-columns:minmax(340px,1fr) minmax(340px,1fr);align-items:start;gap:18px;display:grid}@media (width<=900px){.solution-split{grid-template-columns:1fr}}.prose{max-width:760px}.prose pre{background:var(--code-bg);border:1px solid var(--line);border-radius:10px;padding:12px;font-size:13.5px;overflow-x:auto}.prose code{font-family:ui-monospace,SF Mono,Menlo,monospace;font-size:.92em}.prose h1{font-size:22px}.prose blockquote{border-left:3px solid var(--accent);color:var(--muted);margin-left:0;padding-left:14px}.code-tabs{background:var(--panel);border:1px solid var(--line);border-radius:12px;overflow:hidden}.code-tabbar{border-bottom:1px solid var(--line);display:flex}.code-box{max-height:560px;overflow:auto}.code-box .shiki{margin:0;padding:14px 0;font-size:13.5px;line-height:1.5;background:var(--code-bg)!important}.code-box .line{width:100%;padding:0 14px;transition:background-color .25s;display:inline-block}.code-box .line.line-hl{background:var(--hl-line)}.player{background:var(--panel);border:1px solid var(--line);border-radius:12px;outline:none;padding:12px}.player:focus-visible{border-color:var(--accent)}.player-svg{width:100%;height:auto;max-height:440px;display:block}.player-caption{min-height:44px;padding:8px 4px 4px;font-size:14px}.player-vars{flex-wrap:wrap;gap:8px;padding-top:8px;display:flex}.var-chip{background:var(--accent-soft);color:var(--ink);border-radius:8px;padding:2px 8px;font-family:ui-monospace,Menlo,monospace;font-size:12.5px}.player-controls{align-items:center;gap:6px;padding-top:6px;display:flex}.player-controls button{background:var(--bg);color:var(--ink);border:1px solid var(--line);cursor:pointer;border-radius:8px;padding:5px 10px;font-size:13px}.player-controls button:disabled{opacity:.4}.player-controls .play-btn{background:var(--accent);color:#fff;border-color:var(--accent);min-width:42px}.player-scrub{accent-color:var(--accent);flex:1;min-width:60px}.player-count{color:var(--muted);white-space:nowrap;font-size:12px}.player-controls select{background:var(--bg);color:var(--ink);border:1px solid var(--line);border-radius:6px;padding:4px}.prim{transition:transform .35s cubic-bezier(.35,0,.25,1),opacity .3s}.prim.enter,.prim.exit{opacity:0}.cell-shape{fill:var(--cell-bg);stroke:var(--cell-line);stroke-width:1.4px;transition:fill .3s,stroke .3s}.cell-text{fill:var(--ink);text-anchor:middle;dominant-baseline:central;font-family:ui-monospace,Menlo,monospace;font-size:15px}.style-active .cell-shape{fill:var(--style-active-bg);stroke:var(--style-active);stroke-width:2px}.style-compare .cell-shape{fill:var(--style-compare-bg);stroke:var(--style-compare);stroke-width:2px}.style-done .cell-shape{fill:var(--style-done-bg);stroke:var(--style-done)}.style-reject .cell-shape{fill:var(--style-reject-bg);stroke:var(--style-reject)}.style-found .cell-shape{fill:var(--style-found-bg);stroke:var(--style-found);stroke-width:2.2px}.viz-label{fill:var(--muted);text-anchor:middle;font-size:11px}.prim-label.entlabel .viz-label{text-anchor:start;fill:var(--ink);font-size:12px;font-weight:600}.prim-label.idx .viz-label{fill:var(--muted);font-family:ui-monospace,Menlo,monospace}.ptr-tick{fill:var(--accent)}.ptr-text{fill:var(--accent);text-anchor:middle;font-family:ui-monospace,Menlo,monospace;font-size:12px;font-weight:700}.edge-path{stroke:var(--cell-line);stroke-width:1.6px;fill:none;transition:stroke .3s,d .35s}.prim-edge.style-active .edge-path{stroke:var(--style-active);stroke-width:2.4px}.prim-edge.style-compare .edge-path{stroke:var(--style-compare);stroke-width:2.4px}.prim-edge.style-done .edge-path{stroke:var(--style-done)}.prim-edge.style-reject .edge-path{stroke:var(--style-reject)}.prim-edge.style-found .edge-path{stroke:var(--style-found);stroke-width:2.6px}.arrowhead{fill:var(--cell-line)}.bracket-path{stroke:var(--accent);stroke-width:2px;fill:none}.outline-rect{stroke:var(--accent);stroke-width:2px;fill:none;stroke-dasharray:5 3}.auth-widget{align-items:center;gap:10px;margin-left:auto;font-size:13px;display:flex}.linkish{color:var(--accent);cursor:pointer;background:0 0;border:none;padding:0;font-size:13px}.enroll-link{font-size:13px}.enroll-form{gap:10px;margin:14px 0;display:flex}.enroll-form input{background:var(--panel);color:var(--ink);border:1px solid var(--line);border-radius:8px;min-width:220px;padding:9px 12px;font-size:15px}.rate-bar{border-top:1px solid var(--line);flex-wrap:wrap;align-items:center;gap:8px;margin-top:26px;padding-top:14px;display:flex}.rate{border:1px solid var(--line);background:var(--panel);color:var(--ink);cursor:pointer;border-radius:8px;padding:6px 14px;font-size:13.5px}.rate-again:hover{border-color:var(--style-reject);color:var(--style-reject)}.rate-hard:hover{border-color:var(--style-active);color:var(--style-active)}.rate-good:hover{border-color:var(--style-compare);color:var(--style-compare)}.rate-easy:hover{border-color:var(--style-found);color:var(--style-found)}.progress-grid{flex-direction:column;gap:8px;max-width:560px;display:flex}.progress-row{grid-template-columns:180px 1fr auto;align-items:center;gap:10px;font-size:13.5px;display:grid}.bar{background:var(--line);border-radius:4px;height:8px;overflow:hidden}.bar-fill{background:var(--accent);border-radius:4px;height:100%;transition:width .3s}.attempt-toolbar{align-items:center;gap:8px;margin-bottom:8px;display:flex}.attempt-toolbar .spacer{flex:1}.editor-host{border:1px solid var(--line);border-radius:10px;overflow:hidden}.editor-host .cm-editor{min-height:220px;max-height:480px}.editor-host .cm-scroller{overflow:auto}.run-result{background:var(--panel);border:1px solid var(--line);border-radius:12px;margin-top:14px;padding:12px 16px}.run-head{margin:2px 0 8px;font-weight:700}.run-head.ok{color:var(--style-found)}.run-head.bad{color:var(--style-reject)}.fail-case{border-top:1px solid var(--line);padding:8px 0;font-size:13.5px}.fail-title code{font-size:12.5px}.ev{flex-direction:column;gap:2px;margin-top:4px;display:flex}.debug-out{background:var(--code-bg);border:1px solid var(--line);white-space:pre-wrap;border-radius:8px;max-height:220px;padding:8px 10px;font-size:12.5px;overflow:auto}.debug-out.stderr{color:var(--style-reject)}.debug-details summary{cursor:pointer;color:var(--muted);margin:6px 0;font-size:13px}.coach-bar{border-top:1px solid var(--line);flex-wrap:wrap;align-items:center;gap:6px;margin-top:10px;padding-top:10px;display:flex}.coach-hint{background:var(--accent-soft);border-radius:12px;margin-top:10px;padding:10px 14px}.coach-level{text-transform:uppercase;letter-spacing:.05em;color:var(--accent);font-size:11px;font-weight:700}.coach-text{white-space:pre-wrap;margin-top:4px;font-size:14px}.debug-viz-item{margin-bottom:28px}@media (width<=640px){.player-svg{max-height:300px}h1{font-size:21px}}