:root{
  --bg:#ffffff; --panel:#ffffff; --line:#e3e6ea; --ink:#16202c; --muted:#6b7684; --accent:#2563eb; --accent-bg:#e8f0fe;
  --ok:#0a8a4f; --warn:#b45309; --warn-bg:#fff4e0; --hl:#fff3a3;
  --mono:ui-monospace,"Cascadia Mono",Consolas,Menlo,monospace; --sans:system-ui,"Segoe UI",Roboto,sans-serif;
}
*{box-sizing:border-box}
html,body{margin:0;height:100%;background:var(--bg);color:var(--ink);font:14px/1.45 var(--sans)}
.hide{display:none!important}
.muted{color:var(--muted);font-size:12px}
button{font:inherit;cursor:pointer}
.top{display:flex;align-items:center;gap:14px;padding:8px 14px;border-bottom:1px solid var(--line);position:relative;height:52px}
.brand{white-space:nowrap;font-size:15px}.brand .sub{color:var(--muted);font-size:11.5px;margin-left:8px}
#chapters{display:flex;gap:6px;flex:1;overflow-x:auto;scrollbar-width:thin;padding:2px}
.chip{display:flex;align-items:center;gap:6px;border:1px solid var(--line);background:#fff;border-radius:999px;padding:4px 11px 4px 5px;font-size:12px;white-space:nowrap;color:var(--ink)}
.chip i{font-style:normal;background:#eef1f5;border-radius:999px;min-width:20px;height:20px;display:grid;place-items:center;font-size:11px;font-weight:600}
.chip.on{border-color:var(--accent);background:var(--accent-bg)}.chip.on i{background:var(--accent);color:#fff}
.chip.done i{background:var(--ok);color:#fff}
.chip.locked{opacity:.45;cursor:default}.chip.soon{font-style:italic}
.ghost{border:1px solid var(--line);background:#fff;border-radius:8px;padding:5px 10px}
.prog{position:absolute;left:0;bottom:-1px;height:3px;width:100%;background:transparent}
#progress{height:3px;background:var(--accent);width:0;transition:width .4s}

.grid{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(0,1fr);grid-template-rows:minmax(0,1fr) minmax(0,1fr);gap:10px;padding:10px;height:calc(100vh - 53px)}
.pane{border:1px solid var(--line);border-radius:10px;display:flex;flex-direction:column;min-height:0;min-width:0;background:var(--panel);overflow:hidden;transition:box-shadow .25s,border-color .25s}
.ph{display:flex;align-items:center;gap:10px;padding:7px 12px;border-bottom:1px solid var(--line);background:#fafbfc}
.ph h3{margin:0;font-size:13px;font-weight:650}
.pill{margin-left:auto;background:var(--accent-bg);color:var(--accent);border-radius:999px;padding:1px 9px;font-size:12px}
.sim{font-weight:500;font-size:10.5px;color:var(--muted);border:1px solid var(--line);border-radius:6px;padding:0 5px;margin-left:6px}

/* topology */
.palette-wrap{display:flex;align-items:center;gap:10px;padding:6px 12px;border-bottom:1px dashed var(--line)}
#palette{display:flex;gap:8px;flex-wrap:wrap}
.pal{display:flex;align-items:center;gap:7px;border:1.5px solid;border-radius:9px;padding:4px 9px;cursor:grab;user-select:none;touch-action:none;font-size:12.5px;background:#fff}
.pal .pal-dot{width:9px;height:9px;border-radius:3px;background:currentColor}
.pal .pal-c{background:#eef1f5;color:var(--ink);border-radius:999px;padding:0 7px;font-size:11px;font-weight:600}
.pal.empty{opacity:.35;cursor:not-allowed}
.k-spine{color:#3b6fd4;border-color:#3b6fd4}.k-leaf{color:#2e8b57;border-color:#2e8b57}.k-border{color:#e08a00;border-color:#e08a00}.k-host{color:#6b7280;border-color:#6b7280}.k-wan{color:#8a4fd0;border-color:#8a4fd0}
.pal .pal-l{color:var(--ink)}
.drag-ghost{position:fixed;transform:translate(-50%,-50%);pointer-events:none;z-index:50;background:#fff;border:2px solid;border-radius:10px;padding:8px 16px;font-weight:600;box-shadow:0 8px 24px rgba(0,0,0,.18)}
.canvas{flex:1;min-height:0;display:flex}
#topo{width:100%;height:100%}
.inspector{padding:5px 12px;border-top:1px solid var(--line);min-height:28px}
.tier{font:600 10px var(--sans);fill:#a0a8b4;letter-spacing:.08em}
.ghost-t{font:11px var(--sans);text-transform:uppercase;opacity:.7}
.ghost rect{opacity:.5}
#topo[data-drag="spine"] .ghost[data-kind="spine"] rect,#topo[data-drag="leaf"] .ghost[data-kind="leaf"] rect,#topo[data-drag="border"] .ghost[data-kind="border"] rect,#topo[data-drag="host"] .ghost[data-kind="host"] rect,#topo[data-drag="wan"] .ghost[data-kind="wan"] rect{opacity:1;stroke-width:2.5;fill:rgba(37,99,235,.06)}
.node{cursor:pointer}.node:hover rect:first-child{filter:brightness(.97)}
.node.sel rect:first-child{stroke-width:3}
.node.picked rect:first-child{stroke:var(--accent);stroke-width:4}
.node.hint rect:first-child{animation:hint 1.1s ease-in-out infinite}
@keyframes hint{50%{stroke-width:5;filter:drop-shadow(0 0 6px rgba(37,99,235,.7))}}
.n-name{font:700 13.5px var(--sans);fill:var(--ink)}.n-role{font:10px var(--sans);fill:var(--muted)}
.bdg{fill:#fff;stroke:#c9d1db}.bdg-t{font:600 10px var(--sans);fill:#1d4ed8}
.cab{stroke:#8b97a7;stroke-width:2}
.plab-bg{fill:#fff;stroke:#d3d9e1}.plab{font:9.5px var(--mono);fill:#475569}
.pulse{cursor:pointer}
.pulse .dot{fill:#ef4444;stroke:#fff;stroke-width:2}
.pulse .rip{fill:none;stroke:#ef4444;stroke-width:2.5;opacity:0;animation:rip 1.5s ease-out infinite}
.pulse .r2{animation-delay:.75s}
@keyframes rip{0%{r:8;opacity:.9}100%{r:34;opacity:0}}
.plbl-bg{fill:#ef4444}.plbl{font:600 10.5px var(--sans);fill:#fff}

/* console */
.tabs{display:flex;gap:4px;flex-wrap:wrap}
.tab{border:1px solid var(--line);background:#fff;border-radius:7px;padding:2px 9px;font-size:12px}
.tab.on{background:#111827;color:#fff;border-color:#111827}
.tab.flash{animation:flash 0.5s 3;border-color:var(--accent)}
@keyframes flash{50%{background:var(--hl)}}
.term{flex:1;min-height:0;overflow:auto;background:#0f172a;color:#e5e7eb;font:12.5px/1.5 var(--mono);padding:10px 12px;white-space:pre-wrap;word-break:break-word}
.ln.out{color:#aab4c4}.ln.dim{opacity:.6}.pr{color:#7dd3fc}.tx{color:#fff}
.cursor{display:inline-block;width:7px;height:14px;background:#e5e7eb;vertical-align:-2px;animation:cur 1s steps(1) infinite}
@keyframes cur{50%{opacity:0}}
.ctl{display:flex;align-items:center;gap:8px;flex-wrap:wrap;padding:7px 10px;border-top:1px solid var(--line);background:#fafbfc}
.btn{border:1px solid var(--line);background:#fff;border-radius:8px;padding:4px 11px;font-size:12.5px}
.btn:disabled{opacity:.45;cursor:default}
.btn.primary{background:var(--accent);color:#fff;border-color:var(--accent)}
.btn.primary:disabled{background:#c9d6f5;border-color:#c9d6f5;color:#fff}
.btn.big{padding:9px 20px;font-size:14px;border-radius:10px}
#btn-cont.wait{animation:glow 1s ease-in-out infinite}
@keyframes glow{50%{box-shadow:0 0 0 5px rgba(37,99,235,.3)}}
.spd,.opt{font-size:12px;color:var(--muted);display:flex;align-items:center;gap:5px}.spd input{width:80px}

/* explain */
.explain{flex:1;min-height:0;overflow:auto;padding:10px;display:flex;flex-direction:column;gap:8px}
.card{border:1px solid var(--line);border-radius:9px;padding:9px 11px;background:#fff;opacity:.72;transition:opacity .2s}
.card.current{opacity:1;border-color:var(--accent);box-shadow:0 0 0 3px rgba(37,99,235,.08)}
.c-cmd{display:flex;align-items:center;gap:8px;margin-bottom:5px;flex-wrap:wrap}
.card .c-cmd code{background:#0f172a;color:#fff;border-radius:6px;padding:2px 8px;font:12px var(--mono)}
.c-dev{font-size:11px;font-weight:600;background:#eef1f5;border-radius:6px;padding:1px 7px}.c-dev.wire{background:#fde8e8;color:#b91c1c}
.c-sec{font-size:13px;margin-top:4px}.c-sec b.c-h{display:block;font-size:10.5px;text-transform:uppercase;letter-spacing:.06em;color:var(--muted);margin-bottom:1px}
.c-sec.warn{background:var(--warn-bg);border-radius:7px;padding:5px 8px;color:#7c3a00}.c-sec.warn b.c-h{color:var(--warn)}
.c-sec.click{color:#b91c1c;font-size:12px}
.card.wire{border-color:#f3b4b4;background:#fffafa}.card.note{background:#f8fafc;opacity:.85}
.card code,.fnote code{font:12px var(--mono);background:#eef1f5;border-radius:4px;padding:0 4px}
a.lnk{color:var(--accent);cursor:pointer;text-decoration:underline}

/* wireshark */
#pane-ws.alert{border-color:#ef4444;animation:pane 1.1s ease-in-out infinite}
#pane-ws.flash{box-shadow:0 0 0 6px rgba(239,68,68,.35)}
@keyframes pane{50%{box-shadow:0 0 0 6px rgba(239,68,68,.28)}}
.wtabs{margin-left:auto;display:flex;gap:4px}.wtab{border:1px solid var(--line);background:#fff;border-radius:7px;padding:2px 10px;font-size:12px}.wtab.on{background:var(--accent-bg);border-color:var(--accent);color:var(--accent)}
#ws-packets{display:flex;flex-direction:column;flex:1;min-height:0}
.banner{display:flex;align-items:center;gap:8px;background:#fef2f2;color:#b91c1c;padding:5px 12px;font-size:12.5px;cursor:pointer;border-bottom:1px solid #fecaca}
.banner .dot{width:9px;height:9px;border-radius:50%;background:#ef4444;animation:blinkd 1s infinite}.banner u{margin-left:auto}
@keyframes blinkd{50%{opacity:.2}}
.wbar{display:flex;gap:8px;align-items:center;padding:4px 10px;border-bottom:1px solid var(--line);font-size:12px;flex-wrap:wrap}
.wbar input{flex:1;min-width:120px;border:1px solid var(--line);border-radius:6px;padding:2px 7px;font:12px var(--mono);background:#f4fbf4}
.fchip{border:1px solid var(--line);background:#fff;border-radius:6px;padding:0 7px;font-size:11px}
.pklist{height:38%;min-height:90px;overflow:auto;border-bottom:2px solid var(--line)}
.pklist table{width:100%;border-collapse:collapse;font:11.5px var(--mono)}
.pklist th{position:sticky;top:0;background:#eef1f5;text-align:left;padding:2px 8px;font:600 11px var(--sans);border-bottom:1px solid var(--line)}
.pklist td{padding:1.5px 8px;white-space:nowrap}
.pklist tr{cursor:pointer}.pklist tr.sel{outline:2px solid #1d4ed8;outline-offset:-2px;filter:brightness(.93)}
.pklist tr.fresh td{box-shadow:inset 0 0 0 100px rgba(239,68,68,.07)}
.pklist td.info{max-width:420px;overflow:hidden;text-overflow:ellipsis}
.pklist td.info.blink{animation:infoblink .8s steps(1) infinite;font-weight:700}
@keyframes infoblink{0%,100%{background:#facc15;color:#000}50%{background:transparent}}
.pkdetail{flex:1;min-height:0;overflow:auto;padding:6px 10px;font:12px var(--mono)}
.pkdetail details{margin-bottom:2px}.pkdetail summary{cursor:pointer;background:#f1f5f9;padding:1px 6px;border-radius:4px;font-weight:600}
.fld{padding:1px 0 1px 18px}.fk{color:#334155}.fv{color:#0b5fa5}
.kids{margin-left:14px;border-left:1px dotted #cbd5e1}
.fld.hl{background:#fffbe0}
.fld.key{background:var(--hl);animation:keyb 1s ease-in-out 4;outline:1.5px solid #eab308;border-radius:3px}
@keyframes keyb{50%{background:#fde047}}
.fnote{font:11.5px var(--sans);color:#7a5200;background:#fff7d6;border-radius:5px;padding:2px 7px;margin:2px 0 3px;max-width:560px;white-space:normal}
.empty-ws{color:var(--muted);padding:12px;font-family:var(--sans)}

/* encapsulation */
.encap{padding:12px;overflow:auto;height:100%}
#ws-encap{flex:1;min-height:0;overflow:auto}
.enc-note{color:var(--muted);font-size:12px;margin-bottom:8px}
.stack{display:flex;gap:3px;flex-wrap:wrap}
.seg{border-radius:8px;padding:6px 9px;border:1.5px solid;display:flex;flex-direction:column;min-width:110px;font-size:12px}
.seg b{font-size:12px}.seg small{color:var(--muted)}.seg span{font:11px var(--mono);word-break:break-all}
.s-out{background:#eaf2ff;border-color:#93b4ee}.s-vx{background:#fff2cf;border-color:#e0a800}.s-in{background:#e8f6ec;border-color:#86c79b}
.bits{display:flex;margin:12px 0;border:1.5px solid #e0a800;border-radius:8px;overflow:hidden;font-size:12px}
.bit{padding:6px 10px;text-align:center}.bit small{color:var(--muted)}.bit.f{flex:8;background:#fff8dc}.bit.r{flex:6;background:#f8fafc}.bit.v{flex:10;background:#ffe9a0;font-weight:700}
.enc-math{font-size:13px;background:#f8fafc;border:1px solid var(--line);border-radius:8px;padding:9px 12px}

/* coach */
#coach-wrap{position:fixed;inset:0;background:rgba(255,255,255,.72);backdrop-filter:blur(2px);display:none;align-items:center;justify-content:center;z-index:40}
#coach-wrap.on{display:flex}
.coach{width:min(560px,92vw);background:#fff;border:1px solid var(--line);border-radius:16px;padding:24px 26px;box-shadow:0 20px 60px rgba(15,23,42,.18)}
.coach h2{margin:0 0 8px;font-size:21px}.coach p{margin:0 0 10px;font-size:14.5px}.coach ul{margin:0 0 16px;padding-left:20px}.coach li{margin:3px 0}
#toast{position:fixed;left:50%;bottom:24px;transform:translate(-50%,20px);background:#111827;color:#fff;padding:10px 16px;border-radius:10px;max-width:min(620px,92vw);opacity:0;pointer-events:none;transition:.25s;z-index:60;font-size:13.5px}
#toast.show{opacity:1;transform:translate(-50%,0)}#toast.warn{background:#9a3412}#toast.ok{background:#166534}

@media (max-width:1000px){
  .grid{grid-template-columns:1fr;grid-template-rows:auto;height:auto}
  .pane{min-height:420px}
}

.bum{display:flex;align-items:center;gap:6px;font-size:12px;color:var(--muted);white-space:nowrap}
.bum>div{display:flex;border:1px solid var(--line);border-radius:8px;overflow:hidden}
.bum button{border:0;background:#fff;padding:4px 10px;font-size:12px}
.bum button.on{background:var(--accent);color:#fff}
#ws-rt{flex:1;min-height:0;overflow:auto}
table.rt{width:100%;border-collapse:collapse;font-size:12.5px;margin:8px 0}
table.rt th{text-align:left;background:#eef1f5;padding:4px 8px;font-size:11.5px}
table.rt td{padding:6px 8px;border-bottom:1px solid var(--line);vertical-align:top}
.tbadge{display:inline-grid;place-items:center;width:24px;height:24px;border-radius:50%;color:#fff;background:#64748b}
.tbadge.t1{background:#7c3aed}.tbadge.t2{background:#2563eb}.tbadge.t3{background:#0d9488}.tbadge.t4{background:#d97706}.tbadge.t5{background:#dc2626}

.fchip{white-space:nowrap}