.unit-page[data-astro-cid-afw6mjhx]{color-scheme:light;max-width:1200px;margin:0 auto;padding:clamp(2rem,6vw,3.5rem) clamp(1.25rem,4vw,1.5rem) 5rem}.back-link[data-astro-cid-afw6mjhx]{display:inline-block;font-family:var(--font-mono);font-size:.78rem;letter-spacing:.05em;color:var(--ink-muted);text-decoration:none;margin-bottom:1.5rem}.back-link[data-astro-cid-afw6mjhx]:hover{color:var(--ink)}.unit-meta[data-astro-cid-afw6mjhx]{display:flex;align-items:center;justify-content:space-between;gap:1rem;margin-bottom:1.5rem}.eyebrow[data-astro-cid-afw6mjhx]{display:flex;align-items:center;gap:.55rem;font-family:var(--font-mono);font-size:.78rem;letter-spacing:.1em;text-transform:uppercase;color:var(--ink-muted);margin:0}.eyebrow-dot[data-astro-cid-afw6mjhx]{width:.5rem;height:.5rem;border-radius:50%;background:var(--stamp-progress);flex-shrink:0}#gj-app{--blue:#2c4f74;--pink:#466461;--ink:#1a1c1e;--muted:#43474e;--bg:#f4f3f7;--card:#ffffff;--line:#c3c6cf;--code-bg:#10385c;--code-fg:#eeedf1;--green:#466461;--amber:#e3d1ac;--radius:12px;--shadow:0 8px 24px rgba(0,80,120,.1);--font:"Segoe UI", system-ui, -apple-system, Roboto, Helvetica, Arial, sans-serif;--mono:"Consolas","SF Mono",Monaco,"Courier New",monospace;all:initial;display:block;width:100%;box-sizing:border-box;font-family:var(--font);color:var(--ink);background:var(--bg);line-height:1.55;padding:16px;border-radius:16px;-webkit-font-smoothing:antialiased}#gj-app *{box-sizing:border-box}#gj-app h1,#gj-app h2,#gj-app h3,#gj-app h4,#gj-app p{margin:0 0 .5em}#gj-app strong{color:var(--ink)}#gj-app :focus-visible{outline:3px solid var(--pink);outline-offset:2px;border-radius:8px}#gj-app .hero{background:linear-gradient(120deg,var(--blue),var(--pink));color:#fff;border-radius:var(--radius);padding:22px 22px 20px;box-shadow:var(--shadow);position:relative;overflow:hidden}#gj-app .hero:after{content:"TCP/IP · 0101";position:absolute;right:-6px;bottom:-14px;font-family:var(--mono);font-size:60px;font-weight:700;color:#ffffff1f;letter-spacing:-3px;white-space:nowrap}#gj-app .hero .kicker{font-size:12px;font-weight:700;letter-spacing:2px;text-transform:uppercase;opacity:.9}#gj-app .hero h1{font-size:34px;font-weight:800;line-height:1.05;margin:.15em 0}#gj-app .hero p{max-width:640px;position:relative;z-index:1}#gj-app .teacher{display:inline-flex;align-items:center;gap:8px;margin-top:8px;background:#ffffff2e;padding:6px 12px;border-radius:999px;font-weight:700;font-size:14px}#gj-app .tabs{display:flex;gap:8px;flex-wrap:wrap;margin:16px 0}#gj-app .tab{appearance:none;cursor:pointer;border:2px solid var(--line);background:var(--card);color:var(--ink);font-family:var(--font);font-weight:700;font-size:14px;padding:9px 14px;border-radius:999px;min-height:44px;transition:transform .12s ease,background .12s ease,color .12s ease,border-color .12s ease}#gj-app .tab:hover{border-color:var(--pink);transform:translateY(-1px)}#gj-app .tab:active{transform:scale(.97)}#gj-app .tab[aria-selected=true]{background:var(--blue);border-color:var(--blue);color:#fff;box-shadow:0 6px 14px #2c4f7459}#gj-app .panel{display:none;animation:gj-fade .25s ease}#gj-app .panel.active{display:block}@keyframes gj-fade{0%{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}#gj-app .card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:16px 18px;box-shadow:var(--shadow);margin:14px 0}#gj-app .card h2{font-size:20px;color:var(--blue);display:flex;align-items:center;gap:8px;flex-wrap:wrap}#gj-app .card h3{font-size:16px;color:var(--ink);margin-top:.9em}#gj-app .tag{display:inline-block;background:var(--pink);color:#fff;font-weight:700;font-size:11px;letter-spacing:.5px;text-transform:uppercase;padding:3px 9px;border-radius:999px;vertical-align:middle}#gj-app .grid2{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:14px}@media(max-width:640px){#gj-app .grid2{grid-template-columns:minmax(0,1fr)}#gj-app .hero h1{font-size:26px}}#gj-app ul.gj,#gj-app ol.gj{padding:0 0 0 1.3em;margin:.3em 0}#gj-app ul.gj li,#gj-app ol.gj li{padding:3px 0}#gj-app ul.gj li::marker{color:var(--pink)}#gj-app ol.gj li::marker{color:var(--blue);font-weight:800}#gj-app .keyterm{border-left:5px solid var(--pink);background:#eef4f2;padding:10px 14px;border-radius:8px;margin:12px 0}#gj-app .keyterm b{color:var(--pink)}#gj-app .tip{border-left:5px solid #8a5a9e;background:#f6eff8;padding:10px 14px;border-radius:8px;margin:12px 0}#gj-app .tip b{color:#6d3f80}#gj-app .disc{border-left:5px solid #b4561f;background:#fcf2ea;padding:10px 14px;border-radius:8px;margin:12px 0}#gj-app .disc>b:first-child{color:#93441a}#gj-app .qbox{border-left:5px solid var(--blue);background:#eef3f8;padding:10px 14px;border-radius:8px;margin:12px 0}#gj-app .qbox>b:first-child{color:var(--blue)}#gj-app .scroll{overflow-x:auto;border-radius:10px;border:1px solid var(--line);margin:10px 0}#gj-app table{border-collapse:collapse;width:100%;min-width:460px;font-size:14px;background:#fff}#gj-app th{background:var(--blue);color:#fff;text-align:left;padding:9px 12px;font-weight:700}#gj-app td{padding:8px 12px;border-top:1px solid var(--line);vertical-align:top}#gj-app tr:nth-child(2n) td{background:#f5f8fb}#gj-app td[contenteditable]{background:#fffdf6;outline-offset:-3px}#gj-app .mono{font-family:var(--mono)}#gj-app .bk-fig{margin:12px auto;max-width:min(100%,max(var(--w,640px),140px));text-align:center}#gj-app .bk-zoom{all:unset;box-sizing:border-box;display:block;cursor:zoom-in;background:#fff;border:1px solid var(--line);border-radius:10px;padding:6px;transition:transform .2s,box-shadow .2s}#gj-app .bk-zoom:hover{transform:translateY(-2px);box-shadow:var(--shadow)}#gj-app .bk-zoom:focus-visible{outline:3px solid var(--pink);outline-offset:2px}#gj-app .bk-zoom img{display:block;width:100%;height:auto;max-height:460px;object-fit:contain}#gj-app .bk-fig figcaption{font-size:13px;color:var(--muted);margin-top:6px;line-height:1.4}#gj-app .bk-fig figcaption b{color:var(--blue);margin-right:4px}dialog.bk-lb{border:none;padding:0;background:transparent;max-width:min(96vw,1200px);max-height:94vh;overflow:visible}dialog.bk-lb::backdrop{background:#0a1420d1}dialog.bk-lb figure{margin:0;background:#fff;border-radius:12px;padding:10px;display:flex;flex-direction:column;align-items:center}dialog.bk-lb img{display:block;max-width:100%;max-height:calc(94vh - 70px);width:auto;height:auto;object-fit:contain}dialog.bk-lb figcaption{font:600 14px/1.4 system-ui,sans-serif;color:#1a1c1e;padding:8px 4px 2px;text-align:center}dialog.bk-lb figcaption b{color:#2c4f74;margin-right:4px}dialog.bk-lb .bk-x{position:absolute;top:-16px;right:-16px;width:44px;height:44px;border-radius:50%;border:2px solid #fff;background:#2c4f74;color:#fff;font-size:18px;cursor:pointer}dialog.bk-lb .bk-x:focus-visible{outline:3px solid #e3d1ac}#gj-app .abtn{cursor:pointer;border:none;border-radius:8px;padding:9px 14px;min-height:44px;font-weight:800;font-family:var(--font);font-size:14px;color:#fff;background:var(--blue);transition:transform .12s,filter .12s}#gj-app .abtn:hover{filter:brightness(1.08);transform:translateY(-1px)}#gj-app .abtn:active{transform:scale(.97)}#gj-app .abtn.alt{background:var(--pink)}#gj-app .abtn.ghost{background:#fff;color:var(--blue);border:2px solid var(--line)}#gj-app .abtn:disabled{opacity:.5;cursor:default;transform:none}#gj-app .row{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin:8px 0}#gj-app .inp{font-family:var(--mono);font-size:15px;padding:8px 10px;min-height:44px;border:2px solid var(--line);border-radius:8px;width:9em;color:var(--ink);background:#fff}#gj-app .inp:focus{border-color:var(--blue);outline:none}#gj-app label.sl{display:flex;flex-wrap:wrap;align-items:center;gap:8px;max-width:100%;font-size:14px;font-weight:600}#gj-app label.sl>*{min-width:0;max-width:100%}#gj-app input[type=range]{accent-color:var(--blue);width:150px}#gj-app .res{font-weight:700;font-size:14px;min-height:20px;margin-top:6px}#gj-app .res.ok{color:#1f7a4f}#gj-app .res.no{color:#b3261e}#gj-app .prompt{background:#f4f7fa;border:1px dashed var(--line);border-radius:10px;padding:12px 14px;margin:8px 0;font-size:15px}#gj-app .choices{display:flex;flex-wrap:wrap;gap:8px;margin:8px 0}#gj-app .choice{cursor:pointer;border:2px solid var(--line);background:#fff;color:var(--ink);border-radius:999px;padding:8px 14px;min-height:44px;font:700 14px var(--font);transition:border-color .12s,background .12s}#gj-app .choice:hover{border-color:var(--blue)}#gj-app .choice:active{transform:scale(.97)}#gj-app .choice.correct{background:#e6f5ee;border-color:#1f7a4f;color:#1f7a4f}#gj-app .choice.wrong{background:#fdeeee;border-color:#b3261e;color:#b3261e}#gj-app .viz{background:linear-gradient(180deg,#10385c,#1c4560);color:#eaf6ff;border-radius:var(--radius);padding:16px;box-shadow:var(--shadow);margin:14px 0}#gj-app .viz h3{color:#fff;margin-top:0}#gj-app .viz strong{color:#fff}#gj-app .viz .prompt strong,#gj-app .viz .order strong{color:var(--blue)}#gj-app .viz label.sl{color:#eaf6ff}#gj-app .viz .abtn:not(.alt):not(.ghost){background:var(--amber);color:#10385c}#gj-app .viz .abtn.alt{background:#466461}#gj-app .viz .abtn.ghost{background:transparent;color:#eaf6ff;border-color:#ffffff59}#gj-app .viz .res.ok{color:#9ff5c8}#gj-app .viz .res.no{color:#ffb4ab}#gj-app .viz canvas{display:block;max-width:100%;height:auto;background:#0b2a45;border-radius:10px}#gj-app .log{background:#00000040;border-radius:10px;padding:10px 12px;font-family:var(--mono);font-size:13px;min-height:60px;max-height:190px;overflow-y:auto}#gj-app .log div{padding:2px 0;border-bottom:1px solid rgba(255,255,255,.06)}#gj-app .order{list-style:none;padding:0;margin:8px 0;display:flex;flex-direction:column;gap:6px}#gj-app .order li{display:flex;gap:8px;align-items:center;background:#fff;color:var(--ink);border:2px solid var(--line);border-radius:9px;padding:6px 8px}#gj-app .order li span{flex:1;font-size:14px}#gj-app .order li.good{border-color:#1f7a4f;background:#e6f5ee}#gj-app .order li.bad{border-color:#b3261e;background:#fdeeee}#gj-app .mv{all:unset;cursor:pointer;width:44px;height:44px;display:flex;align-items:center;justify-content:center;border-radius:8px;background:#eef3f8;color:var(--blue);font-weight:900;flex:0 0 auto}#gj-app .mv:hover{background:#dde8f2}#gj-app .mv:focus-visible{outline:3px solid var(--pink)}#gj-app .matrix{display:grid;grid-template-columns:28px repeat(5,minmax(0,1fr));gap:5px;max-width:420px}#gj-app .matrix .lbl{font:800 12px var(--mono);display:flex;align-items:center;justify-content:center;color:#a7c9f5}#gj-app .key{all:unset;box-sizing:border-box;cursor:pointer;height:46px;border-radius:8px;background:#e9eef3;color:#10385c;font:800 16px var(--mono);display:flex;align-items:center;justify-content:center;box-shadow:0 3px #8fa3b7;transition:transform .06s}#gj-app .key:active,#gj-app .key.down{transform:translateY(3px);box-shadow:none;background:#9ff5c8}#gj-app .key:focus-visible{outline:3px solid var(--amber)}#gj-app .key.hl{background:#cfe3f5}#gj-app .matrix .lbl.hl{color:#9ff5c8}#gj-app .cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:12px}#gj-app .flip{all:unset;display:block;box-sizing:border-box;perspective:900px;height:140px;cursor:pointer}#gj-app .flip:focus-visible{outline:3px solid var(--pink);outline-offset:2px;border-radius:10px}#gj-app .flip .inner{position:relative;display:block;width:100%;height:100%;transition:transform .5s;transform-style:preserve-3d}#gj-app .flip.on .inner{transform:rotateY(180deg)}#gj-app .flip .side{position:absolute;inset:0;backface-visibility:hidden;border-radius:10px;padding:12px;display:flex;flex-direction:column;justify-content:center;text-align:center;box-shadow:var(--shadow)}#gj-app .flip .front{background:var(--blue);color:#fff;font-weight:800;font-size:15px}#gj-app .flip .front small{font-weight:600;opacity:.85;font-size:11px;margin-top:6px}#gj-app .flip .back{background:#fff;border:2px solid var(--pink);color:var(--ink);font-size:13px;transform:rotateY(180deg)}#gj-app .acc{border:1px solid var(--line);border-radius:10px;overflow:hidden;margin:10px 0;background:#fff}#gj-app .acc .head{all:unset;box-sizing:border-box;width:100%;cursor:pointer;padding:12px 14px;min-height:44px;font-weight:700;background:#f4f8fb;display:flex;justify-content:space-between;gap:10px;align-items:center;color:var(--ink)}#gj-app .acc .head:hover{background:#e9f1f8}#gj-app .acc .head:focus-visible{outline:3px solid var(--pink);outline-offset:-3px}#gj-app .acc .chev{color:var(--pink);font-weight:900;transition:transform .2s}#gj-app .acc.on .chev{transform:rotate(90deg)}#gj-app .acc .body{display:none;padding:12px 14px;border-top:1px dashed var(--line)}#gj-app .acc.on .body{display:block}#gj-app .marks{font:700 12px var(--mono);color:var(--muted);white-space:nowrap}#gj-app .q{margin:14px 0;padding:14px;border:1px solid var(--line);border-radius:10px;background:#fff}#gj-app .q .opts{display:flex;flex-direction:column;gap:8px;margin-top:8px}#gj-app .opt{cursor:pointer;text-align:left;border:2px solid var(--line);background:#fff;color:var(--ink);border-radius:9px;padding:10px 12px;min-height:44px;font-family:var(--font);font-size:14px;font-weight:600;transition:border-color .12s}#gj-app .opt:hover{border-color:var(--blue)}#gj-app .opt.correct{background:#e6f5ee;border-color:#1f7a4f;color:#1f7a4f}#gj-app .opt.wrong{background:#fdeeee;border-color:#b3261e;color:#b3261e}#gj-app .opt:disabled{cursor:default}#gj-app .score{font-weight:800;color:var(--blue);font-size:16px;margin-top:6px}#gj-app .foot{text-align:center;color:var(--muted);font-size:12px;margin-top:14px}@media(hover:none){#gj-app .bk-zoom:hover,#gj-app .rung:hover{transform:none}}@media(prefers-reduced-motion:reduce){#gj-app *{animation:none!important;transition:none!important}}#gj-app .net{width:100%;max-width:680px;display:block;margin:6px auto;background:#0b2a45;border-radius:10px}#gj-app .net .edge{stroke:#5f86a8;stroke-width:3;stroke-linecap:round;transition:stroke .2s}#gj-app .net .edge.circ{stroke:#e3d1ac;stroke-width:6}#gj-app .net .edge.cut{stroke:#ff8a80;stroke-dasharray:6 7;opacity:.7}#gj-app .net .hit{stroke:transparent;stroke-width:18;cursor:pointer}#gj-app .net .node circle{fill:#1c4560;stroke:#a7c9f5;stroke-width:2}#gj-app .net .node.end circle{fill:#466461;stroke:#9ff5c8}#gj-app .net .node text{fill:#fff;font:700 12px var(--mono);text-anchor:middle;dominant-baseline:central;pointer-events:none}#gj-app .net .pkt{transition:transform .38s linear,opacity .3s}#gj-app .net .pkt circle{fill:#e3d1ac;stroke:#10385c;stroke-width:2}#gj-app .net .pkt.ack circle{fill:#9ff5c8}#gj-app .net .pkt.dead circle{fill:#ff8a80}#gj-app .net .pkt text{fill:#10385c;font:800 10px var(--mono);text-anchor:middle;dominant-baseline:central}#gj-app .buf{display:flex;gap:5px;flex-wrap:wrap;margin:8px 0}#gj-app .bslot{min-width:40px;height:40px;padding:0 6px;border-radius:7px;border:1px dashed rgba(255,255,255,.4);display:flex;flex-direction:column;align-items:center;justify-content:center;font:800 13px var(--mono);line-height:1.05}#gj-app .bslot small{font-size:9px;opacity:.75;font-weight:600}#gj-app .bslot.got{background:#4c6a67;border:1px solid #9ff5c8}#gj-app .bslot.lost{background:#7a3b2e;border:1px solid #ffb4ab}#gj-app .viz select,#gj-app .viz .inp{color:var(--ink)}#gj-app select.inp{width:auto;max-width:100%;font-family:var(--font)}#gj-app label.chk{display:inline-flex;align-items:center;gap:8px;font-size:14px;font-weight:600;min-height:44px}#gj-app label.chk input{width:20px;height:20px;accent-color:var(--amber)}#gj-app .stage{display:grid;grid-template-columns:150px 1fr;gap:14px;align-items:start}@media(max-width:620px){#gj-app .stage{grid-template-columns:minmax(0,1fr)}}#gj-app .lstack{display:flex;flex-direction:column;gap:5px}#gj-app .lstack span{padding:7px 10px;border-radius:7px;background:#ffffff14;font-weight:800;font-size:13px;text-align:center;border:2px solid transparent}#gj-app .lstack span.on{border-color:var(--amber);background:#e3d1ac2e}#gj-app .lstack span.dim{opacity:.4}#gj-app .encap{font:700 12px var(--mono);overflow-x:auto}#gj-app .wrapbox{display:flex;align-items:stretch;gap:4px;padding:4px;border-radius:8px;margin:4px 0;min-width:max-content}#gj-app .wrapbox>.hdr{padding:6px 8px;border-radius:6px;color:#fff;white-space:nowrap;display:flex;flex-direction:column;justify-content:center}#gj-app .wrapbox>.hdr small{font-weight:600;opacity:.85;font-size:10px}#gj-app .w-eth{background:#c48c3c40}#gj-app .w-eth>.hdr{background:#8a5a1f}#gj-app .w-ip{background:#468cbe40}#gj-app .w-ip>.hdr{background:#2f6f9f}#gj-app .w-tcp{background:#6eaa9640}#gj-app .w-tcp>.hdr{background:#3f6f63}#gj-app .dataq{background:#fff;color:#10385c;padding:6px 8px;border-radius:6px;white-space:pre;display:flex;align-items:center}#gj-app .bits{font:700 12px var(--mono);word-break:break-all;color:#9ff5c8;background:#00000040;padding:8px 10px;border-radius:8px}#gj-app .rt td,#gj-app .rt th{font-size:13px}#gj-app .rt tr.hit td{background:#fff3cd!important;font-weight:800}#gj-app .macbig{font:800 26px var(--mono);letter-spacing:1px;margin:8px 0;display:flex;flex-wrap:wrap;gap:2px}#gj-app .macbig .oui{color:var(--amber)}#gj-app .macbig .nic{color:#9ff5c8}#gj-app .ascii{display:flex;flex-wrap:wrap;gap:3px;margin:8px 0}#gj-app .ascii span{display:flex;flex-direction:column;align-items:center;min-width:28px;padding:3px 4px;border-radius:5px;background:#ffffff14;font:700 13px var(--mono)}#gj-app .ascii span small{font-size:10px;color:#a7c9f5}#gj-app .ascii span.ctl{background:#7a3b2e}#gj-app .mailgrid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin:8px 0}@media(max-width:620px){#gj-app .mailgrid{grid-template-columns:minmax(0,1fr)}}#gj-app .mbox{background:#ffffff12;border-radius:10px;padding:10px;min-height:120px}#gj-app .mbox h4{font-size:13px;margin-bottom:6px;color:#fff}#gj-app .mbox div{font:600 12px var(--mono);background:#ffffff1a;border-radius:6px;padding:5px 7px;margin:4px 0}#gj-app .hops{display:flex;flex-wrap:wrap;gap:6px;align-items:center;margin:8px 0}#gj-app .hopnode{background:#ffffff1a;padding:8px 10px;border-radius:8px;font-weight:800;font-size:13px}#gj-app .hopbtn{cursor:pointer;border:2px dashed rgba(255,255,255,.4);background:transparent;color:#e3d1ac;border-radius:999px;padding:6px 12px;min-height:44px;font:800 13px var(--mono)}#gj-app .hopbtn.on{background:#e3d1ac;color:#10385c;border-style:solid}#gj-app .swarm{border-collapse:separate;border-spacing:3px;min-width:0;background:transparent;font-size:12px}#gj-app .swarm th,#gj-app .swarm td{background:transparent!important;border:none;padding:0;color:#eaf6ff;text-align:center}#gj-app .swarm th{font:800 12px var(--mono);padding-right:8px;text-align:right;white-space:nowrap}#gj-app .swarm .ch{width:22px;height:22px;border-radius:4px;background:#ffffff1a}#gj-app .swarm .ch.have{background:#466461}#gj-app .swarm .ch.new{background:#e3d1ac}#gj-app .swarm .cnt{font:700 11px var(--mono);color:#a7c9f5}#gj-app .swarm tr.choked th{color:#ffb4ab}#gj-app .swarm tr.gone{opacity:.35}#gj-app .match{display:grid;grid-template-columns:1fr auto;gap:8px 12px;align-items:center;margin:10px 0}#gj-app .match .d{background:#f4f7fa;border:1px solid var(--line);border-radius:8px;padding:8px 10px;font-size:14px}#gj-app .match select{min-height:44px}#gj-app .match .good{border-color:#1f7a4f;background:#e6f5ee}#gj-app .match .bad{border-color:#b3261e;background:#fdeeee}#gj-app pre.code{background:var(--code-bg);color:var(--code-fg);font:600 14px/1.5 var(--mono);padding:10px 14px;border-radius:8px;overflow-x:auto;margin:8px 0}#gj-app .err{border-left:5px solid #b3261e;background:#fdeeee;padding:10px 14px;border-radius:8px;margin:12px 0;font-size:14px}#gj-app .err b{color:#b3261e}