:root{--bg:#0d1117;--panel:#161b22;--inset:#010409;--border:#30363d;--border-muted:#21262d;--text:#e6edf3;--muted:#8b949e;--subtle:#6e7681;--accent:#2f81f7;--accent-emphasis:#1f6feb;--ok:#3fb950;--ok-emphasis:#238636;--ok-hover:#2ea043;--warn:#d29922;--err:#f85149;--purple:#bc8cff;--mono:ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;--sans:-apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans", Helvetica, Arial, sans-serif}*{box-sizing:border-box}body{background:var(--bg);color:var(--text);font-family:var(--sans);margin:0;font-size:14px}.app{flex-direction:column;height:100vh;display:flex;overflow:hidden}.content{flex:1;min-height:0;overflow:auto}.muted{color:var(--muted);font-weight:400}.small{font-size:12px}h3{margin:18px 0 8px;font-size:13px}.topbar{border-bottom:1px solid var(--border);background:var(--panel);align-items:center;gap:18px;padding:10px 18px;display:flex}.topbar>strong{white-space:nowrap;font-size:15px}.chapters{gap:4px;display:flex}.chapters a{color:var(--muted);outline-offset:2px;border:1px solid #0000;border-radius:7px;align-items:center;gap:7px;padding:5px 12px 5px 7px;font-size:13px;font-weight:500;text-decoration:none;display:flex}.chapters a:hover{color:var(--text);background:var(--border-muted)}.chapters a.active{color:var(--text);background:var(--bg);border-color:var(--border)}.chapters a:focus-visible{outline:2px solid var(--accent)}.chapter-num{background:var(--border-muted);width:18px;height:18px;color:var(--muted);font-variant-numeric:tabular-nums;border-radius:50%;place-items:center;font-size:11px;display:inline-grid}.chapters a.active .chapter-num{background:var(--accent-emphasis);color:#fff}.code-toggle{font-family:var(--mono);margin-left:auto}.code-toggle.on{background:var(--accent-emphasis);color:#fff;border-color:var(--accent-emphasis)}.stage{border-bottom:1px solid var(--border);background:radial-gradient(120% 90% at 50% -10%, #2f81f714, transparent 60%), var(--panel);grid-template-columns:1fr 340px;gap:0;height:208px;display:grid}.stage-field{position:relative;overflow:hidden}.node{background:var(--bg);border:1px solid var(--border);border-radius:9px;flex-direction:column;gap:1px;width:150px;padding:10px 12px;transition:border-color .25s,box-shadow .25s;display:flex;position:absolute;top:52%;transform:translateY(-50%)}.node-consumer{left:3.5%}.node-provider{right:3.5%}.node-network{text-align:center;border-style:dashed;align-items:center;width:168px;top:16px;left:50%;transform:translate(-50%)}.node.lit{border-color:var(--accent);box-shadow:0 0 0 1px var(--accent), 0 0 22px #2f81f740}.node-title{font-size:13px;font-weight:600}.node-role{color:var(--accent);font-size:11px;font-family:var(--mono)}.node-blurb{color:var(--muted);margin-top:4px;font-size:11px;line-height:1.4}.wire{background:linear-gradient(90deg, transparent, var(--border) 10%, var(--border) 90%, transparent);height:2px;position:absolute;top:52%;left:16%;right:16%}.wire-drop{border-left:1px dashed var(--border);height:calc(52% - 56px);position:absolute;top:56px}.drop-consumer{left:33%}.drop-provider{right:33%}.packet{font-family:var(--mono);color:#fff;white-space:nowrap;border-radius:11px;padding:3px 9px;font-size:11px;font-weight:600;position:absolute;top:52%;transform:translate(-50%,-50%);box-shadow:0 2px 10px #0006}.packet.to-right{animation:.85s both packet-right}.packet.to-left{animation:.85s both packet-left}.packet-req{background:var(--accent-emphasis)}.packet-ack{background:var(--ok-emphasis)}.packet-cb{background:#8957e5}.packet-miss,.packet-err{background:var(--err)}@keyframes packet-right{0%{left:16%}to{left:84%}}@keyframes packet-left{0%{left:84%}to{left:16%}}@media (prefers-reduced-motion:reduce){.packet.to-right{animation:none;left:84%}.packet.to-left{animation:none;left:16%}}.trail{border-left:1px solid var(--border);background:var(--bg);margin:0;padding:10px;list-style:none;overflow:auto}.trail-empty{padding:12px;font-size:13px;line-height:1.5}.trail-row{border-radius:6px;grid-template-columns:10px auto 1fr auto;align-items:center;gap:8px;padding:6px 8px;font-size:12px;display:grid}.trail-row:hover,.trail-row.active{background:var(--border-muted)}.trail-dot{background:var(--border);border-radius:50%;width:8px;height:8px}.phase-req .trail-dot{background:var(--accent)}.phase-ack .trail-dot{background:var(--ok)}.phase-cb .trail-dot{background:var(--purple)}.phase-miss .trail-dot,.phase-err .trail-dot{background:var(--err)}.trail-dir{color:var(--subtle)}.trail-label{color:var(--text);text-overflow:ellipsis;white-space:nowrap;overflow:hidden}.trail-inspect{border:1px solid var(--border);color:var(--accent);cursor:pointer;background:0 0;border-radius:5px;padding:1px 7px;font-size:11px}.trail-inspect:hover{background:var(--accent-emphasis);color:#fff;border-color:var(--accent-emphasis)}.chapter{max-width:1080px;margin:0 auto;padding:22px 24px 60px}.workspace.two-col{grid-template-columns:1fr 1fr;gap:16px;display:grid}.pane{background:var(--panel);border:1px solid var(--border);border-radius:10px;min-width:0;padding:16px 18px}.pane h2:first-child{margin-top:0}h2{text-transform:uppercase;letter-spacing:.06em;color:var(--muted);margin:22px 0 10px;font-size:12px}h2 .ok{color:var(--ok);text-transform:none;letter-spacing:0}h2 .err{color:var(--err);text-transform:none;letter-spacing:0}.lede{margin-bottom:8px}.lede h1{margin:0 0 10px;font-size:26px;line-height:1.2}.lede p{max-width:70ch;margin:0 0 18px;font-size:15px;line-height:1.6}.lede strong{color:var(--text)}.cta-row{flex-wrap:wrap;gap:10px;display:flex}.cta{background:var(--ok-emphasis);color:#fff;border:1px solid #f0f6fc1a;border-radius:7px;padding:9px 16px;font-size:14px;font-weight:600;text-decoration:none;display:inline-block}.cta:hover{background:var(--ok-hover)}.cta.ghost-cta{background:var(--border-muted);color:var(--text);border-color:var(--border);font-weight:500}.cta.ghost-cta:hover{background:var(--border)}.anatomy{grid-template-columns:repeat(3,1fr);gap:14px;display:grid}.card{background:var(--panel);border:1px solid var(--border);border-left:3px solid var(--border);border-radius:9px;padding:14px}.card-tag{font-size:12px;font-weight:700}.card p{margin:6px 0 10px;line-height:1.5}.card pre{margin:0}.accent-accent{border-left-color:var(--accent)}.accent-accent .card-tag{color:var(--accent)}.accent-ok{border-left-color:var(--ok)}.accent-ok .card-tag{color:var(--ok)}.accent-purple{border-left-color:var(--purple)}.accent-purple .card-tag{color:var(--purple)}.glossary{background:var(--border);border:1px solid var(--border);border-radius:9px;gap:1px;margin:0;display:grid;overflow:hidden}.glossary-row{background:var(--panel);grid-template-columns:200px 1fr;gap:14px;padding:11px 14px;display:grid}.glossary dt{font-weight:600}.glossary dd{margin:0;line-height:1.5}button.ghost,.copy{background:var(--border-muted);color:var(--text);border:1px solid var(--border);cursor:pointer;border-radius:6px;padding:4px 10px;font-size:12px;font-weight:500}button.ghost:hover,.copy:hover{background:var(--border)}button.ghost:disabled{opacity:.5;cursor:not-allowed}button.run{background:var(--ok-emphasis);color:#fff;cursor:pointer;border:1px solid #f0f6fc1a;border-radius:6px;margin:14px 0 4px;padding:8px 16px;font-size:13px;font-weight:600;display:block}button.run:hover{background:var(--ok-hover)}button.run:disabled{opacity:.5;cursor:not-allowed;background:var(--ok-emphasis)}.starter-toggle{margin-top:6px}label{color:var(--muted);margin:12px 0 4px;font-size:11px;display:block}.field{width:100%;font:inherit;border:1px solid var(--border);background:var(--inset);color:var(--text);border-radius:6px;margin:4px 0 6px;padding:8px 10px;font-size:13px}.field::placeholder{color:var(--subtle)}.field:focus{border-color:var(--accent);outline:none}.toggle{color:var(--muted);cursor:pointer;align-items:center;gap:6px;margin:10px 0;font-size:13px;display:flex}.toggle code{color:var(--accent)}.controls{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:10px;margin-top:10px;display:flex}textarea{resize:vertical;background:var(--inset);width:100%;min-height:84px;color:var(--text);border:1px solid var(--border);font-family:var(--mono);border-radius:6px;margin-bottom:6px;padding:10px;font-size:12px;line-height:1.5}.meta{color:var(--muted);font-family:var(--mono);margin-bottom:8px;font-size:12px}.meta code,.toggle code{color:var(--accent)}.field-head{justify-content:space-between;align-items:center;gap:8px;display:flex}.field-head label{margin:12px 0 4px}.cm-editor{border:1px solid var(--border);border-radius:6px;overflow:hidden}.cm-editor.cm-focused{border-color:var(--accent);outline:none}.cm-errorLine{background:#f8514926}pre.mono{font-family:var(--mono);background:var(--inset);border:1px solid var(--border);border-radius:6px;margin:0;padding:8px;overflow:auto}pre.small{font-size:12px;line-height:1.45}pre.wrap{white-space:pre-wrap;word-break:break-word}.flow{flex-wrap:wrap;gap:6px;margin:8px 0 4px;display:flex}.chip{font-family:var(--mono);border:1px solid var(--border);color:var(--muted);border-radius:12px;padding:3px 8px;font-size:12px}.chip.fwd{color:var(--accent);border-color:var(--accent)}.chip.cb{color:var(--ok);border-color:var(--ok)}.match{margin-bottom:14px}.match h3{margin:6px 0}.kv{grid-template-columns:90px 1fr;gap:4px 10px;margin:0;display:grid}.kv dt{color:var(--muted)}.kv dd{margin:0}.findings{margin:6px 0 0;padding:0;list-style:none}.finding{border-left:3px solid var(--border);background:var(--bg);border-radius:0 6px 6px 0;margin-bottom:4px;padding:6px 10px;font-size:13px}.finding code{color:var(--text);margin-right:4px}.finding.ok{border-left-color:var(--ok)}.finding.warn{border-left-color:var(--warn)}.finding.err{border-left-color:var(--err)}.ok{color:var(--ok)}.err{color:var(--err)}.starter{margin-top:12px}.starter-code{max-height:320px}.drawer{background:var(--panel);border-left:1px solid var(--border);z-index:50;flex-direction:column;width:min(460px,92vw);transition:transform .22s;display:flex;position:fixed;top:0;bottom:0;right:0;transform:translate(100%);box-shadow:-16px 0 40px #01040980}.drawer.open{transform:translate(0)}.drawer-head{border-bottom:1px solid var(--border);justify-content:space-between;align-items:flex-start;gap:10px;padding:14px 16px;display:flex}.drawer-head strong{font-size:14px}.drawer-sub{margin:2px 0 0}.drawer-actions{align-items:center;gap:6px;display:flex}.drawer-intro{margin:12px 16px 0;line-height:1.5}.drawer-code{flex:1;margin:12px 16px 16px;overflow:auto}.ion-chapter{max-width:1080px}.ion-intro h1{margin:0 0 6px;font-size:22px}.ion-intro p{max-width:80ch;margin:0 0 4px;line-height:1.5}.subtabs{border-bottom:1px solid var(--border);flex-wrap:wrap;gap:6px;margin:16px 0 18px;display:flex}.subtabs button{appearance:none;color:var(--muted);font:inherit;cursor:pointer;background:0 0;border:none;border-bottom:2px solid #0000;padding:8px 10px;font-size:13px}.subtabs button:hover{color:var(--text)}.subtabs button.active{color:var(--text);border-bottom-color:var(--accent)}.subtabs button:focus-visible{outline:2px solid var(--accent);border-radius:4px}select.field{appearance:none;cursor:pointer}.chip:focus-visible{outline:2px solid var(--accent)}button.chip{appearance:none;font:inherit;cursor:pointer;background:0 0}.ion-flow-head select{max-width:280px}.ion-stage-wrap{border:1px solid var(--border);border-radius:9px;margin-bottom:18px;overflow:hidden}.ion-stage-wrap .stage{border-bottom:none}.ion-steps{counter-reset:step;margin:0;padding:0;list-style:none}.ion-step{border-top:1px solid var(--border-muted);padding:10px 0}.ion-step:first-child{border-top:none}.ion-step-head{flex-wrap:wrap;align-items:center;gap:8px;display:flex}.ion-step-name{color:var(--accent);font-weight:600}.ion-step-dir{color:var(--subtle);font-family:var(--mono);font-size:11px}.ion-fields{border-left:2px solid var(--border);margin:6px 0 0;padding:0 0 0 10px;list-style:none}.ion-fields li{color:var(--muted);padding:1px 0}.ion-conditional{margin-top:6px}.ion-conditional summary{cursor:pointer}@media (width<=820px){.workspace.two-col,.anatomy{grid-template-columns:1fr}.stage{grid-template-columns:1fr;height:auto}.trail{max-height:180px}}