:root{
  --bg:#0a0d10;
  --panel:#12161a;
  --panel-2:#161b20;
  --line:#262d34;
  --line-soft:#1c2228;
  --line-strong:#333c46;
  --text:#e6ecf1;
  --muted:#8b96a3;
  --muted-dim:#5d6773;
  --amber:#ffb020;
  --amber-dim:#8a611c;
  --green:#4ade80;
  --green-dim:#1f4a34;
  --blue:#38bdf8;
  --blue-dim:#1a4d63;
  --purple:#a78bfa;
  --red:#ff6b6b;
  --mono:'JetBrains Mono',monospace;
  --sans:'IBM Plex Sans',sans-serif;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  font-family:var(--sans);
  background:var(--bg);
  color:var(--text);
  line-height:1.7;
  overflow-x:hidden;
}
body::before{
  content:"";
  position:fixed;inset:0;
  background-image:
    linear-gradient(rgba(255,255,255,.025) 1px,transparent 1px),
    linear-gradient(90deg,rgba(255,255,255,.025) 1px,transparent 1px);
  background-size:36px 36px;
  pointer-events:none;
  z-index:0;
}
a{color:inherit}
img{max-width:100%;display:block}
::selection{background:var(--amber);color:#0a0d10}
:focus-visible{outline:2px solid var(--amber);outline-offset:3px}

.led{
  width:7px;height:7px;border-radius:50%;
  background:var(--green);
  box-shadow:0 0 6px 1px rgba(74,222,128,.7);
  display:inline-block;
  animation:blink 2.4s ease-in-out infinite;
  flex-shrink:0;
}
.led.amber{background:var(--amber);box-shadow:0 0 6px 1px rgba(255,176,32,.7)}
.led.blue{background:var(--blue);box-shadow:0 0 6px 1px rgba(56,189,248,.7)}
@keyframes blink{0%,60%{opacity:1}62%,68%{opacity:.25}70%,100%{opacity:1}}
@media (prefers-reduced-motion: reduce){
  .led{animation:none}
  *{animation-duration:.001ms !important;animation-iteration-count:1 !important;scroll-behavior:auto !important}
}

/* ---------- Nav ---------- */
nav{
  position:sticky;top:0;z-index:99;
  display:flex;justify-content:space-between;align-items:center;
  padding:16px 8%;
  background:rgba(10,13,16,.9);
  border-bottom:1px solid var(--line);
}
.logo{
  font-family:var(--mono);font-weight:600;font-size:.95rem;
  display:flex;align-items:center;gap:8px;color:var(--text);
  text-decoration:none;
}
.logo .path{color:var(--muted-dim)}
.logo .user{color:var(--amber)}
.logo .back{color:var(--muted);margin-right:2px}
nav .links{display:flex;gap:24px;font-family:var(--mono);font-size:.8rem;align-items:center}
nav .links a{color:var(--muted);text-decoration:none}
nav .links a:hover{color:var(--amber)}
nav .links .repo-btn{
  border:1px solid var(--line);padding:7px 14px;border-radius:3px;color:var(--text);
  transition:.2s;
}
nav .links .repo-btn:hover{border-color:var(--amber);color:var(--amber)}

/* ---------- Breadcrumb / Hero ---------- */
header{padding:64px 8% 50px;position:relative;z-index:1}
.crumb{
  font-family:var(--mono);font-size:.8rem;color:var(--green);
  background:var(--panel);border:1px solid var(--line);
  display:inline-flex;align-items:center;gap:8px;
  padding:8px 14px;border-radius:3px;margin-bottom:26px;
}
.crumb .prompt{color:var(--muted-dim)}

h1{
  font-family:var(--mono);font-weight:700;
  font-size:clamp(2rem,4.2vw,3.1rem);
  line-height:1.2;margin-bottom:16px;letter-spacing:-.01em;
  max-width:900px;
}
.hero-sub{font-size:1.05rem;color:var(--muted);max-width:760px;margin-bottom:26px}

.badge-row{display:flex;flex-wrap:wrap;gap:10px;margin-bottom:34px}
.badge{
  font-family:var(--mono);font-size:.76rem;display:flex;align-items:center;gap:7px;
  border:1px solid var(--line);padding:6px 12px;border-radius:20px;color:var(--muted);
  background:var(--panel);
}
.badge.status{color:var(--green);border-color:var(--green-dim)}

.btn-row{display:flex;gap:14px;flex-wrap:wrap}
.btn{
  display:inline-flex;align-items:center;gap:9px;
  padding:12px 20px;border-radius:3px;
  font-family:var(--mono);font-size:.85rem;font-weight:600;
  text-decoration:none;transition:.2s ease;border:1px solid transparent;
}
.btn.primary{background:var(--amber);color:#161200}
.btn.primary:hover{background:#ffc350;transform:translateY(-2px)}
.btn.secondary{border-color:var(--line);color:var(--text)}
.btn.secondary:hover{border-color:var(--amber);color:var(--amber);transform:translateY(-2px)}
.btn .dot{width:6px;height:6px;border-radius:50%;background:currentColor}

/* ---------- Sections ---------- */
section{padding:64px 8%;position:relative;z-index:1;border-top:1px solid var(--line-soft)}
.section-tag{font-family:var(--mono);color:var(--muted-dim);font-size:.78rem;letter-spacing:.04em;margin-bottom:10px}
.section-tag::before{content:"$ ";color:var(--green)}
.section-title{font-family:var(--mono);font-size:1.55rem;font-weight:700;margin-bottom:16px}
.section-sub{color:var(--muted);max-width:760px;margin-bottom:34px;font-size:.98rem}
.prose{color:var(--muted);max-width:760px;font-size:.98rem}
.prose p{margin-bottom:16px}
.prose strong{color:var(--text)}

/* ---------- Signature hop diagram ---------- */
.hoppanel{
  background:var(--panel);border:1px solid var(--line);border-radius:4px;
  padding:20px 20px 8px;max-width:980px;
}
.hoppanel .hdr{
  display:flex;justify-content:space-between;align-items:center;
  font-family:var(--mono);font-size:.72rem;color:var(--muted-dim);
  padding-bottom:10px;border-bottom:1px solid var(--line-soft);margin-bottom:6px;
  letter-spacing:.04em;text-transform:uppercase;
}
.hoppanel svg{width:100%;height:auto;display:block}

/* ---------- Rack frame (for imported diagrams/screenshots) ---------- */
.rack{
  background:var(--panel);border:1px solid var(--line);border-radius:4px;
  padding:16px;margin-top:28px;max-width:980px;
}
.rack .cap{
  font-family:var(--mono);font-size:.74rem;color:var(--muted-dim);
  padding-top:12px;letter-spacing:.02em;
}
.rack img{border-radius:2px}

/* ---------- SFP stack chips ---------- */
.sfp-grid{display:flex;flex-wrap:wrap;gap:10px}
.sfp{
  font-family:var(--mono);font-size:.8rem;color:var(--text);
  border:1px solid var(--line);background:var(--panel);
  padding:9px 14px 9px 30px;border-radius:3px;position:relative;
}
.sfp::before{
  content:"";position:absolute;left:12px;top:50%;transform:translateY(-50%);
  width:6px;height:6px;border-radius:50%;background:var(--green);
  box-shadow:0 0 5px rgba(74,222,128,.7);
}

/* ---------- Route table cards ---------- */
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:18px}
.route-card{
  background:var(--panel);border:1px solid var(--line);border-radius:4px;padding:20px;
}
.route-card .rt-hdr{
  font-family:var(--mono);font-size:.68rem;color:var(--muted-dim);
  display:flex;justify-content:space-between;align-items:center;
  padding-bottom:12px;border-bottom:1px solid var(--line-soft);margin-bottom:12px;
  letter-spacing:.04em;text-transform:uppercase;
}
.rt-row{display:flex;justify-content:space-between;gap:14px;padding:7px 0;font-size:.86rem}
.rt-row .cidr{font-family:var(--mono);color:var(--amber)}
.rt-row .purpose{color:var(--muted);text-align:right}

/* ---------- BGP peering ---------- */
.peer-wrap{
  background:var(--panel);border:1px solid var(--line);border-radius:4px;
  padding:28px;max-width:980px;
}
.peer-row{display:flex;align-items:center;justify-content:space-between;gap:18px;flex-wrap:wrap}
.peer-node{
  flex:1;min-width:220px;background:var(--panel-2);border:1px solid var(--line-strong);
  border-radius:4px;padding:18px 20px;text-align:center;
}
.peer-node .name{font-family:var(--mono);font-weight:700;font-size:.98rem;margin-bottom:6px}
.peer-node .asn{font-family:var(--mono);font-size:.78rem;color:var(--amber)}
.peer-link{
  flex:0 0 auto;text-align:center;font-family:var(--mono);font-size:.72rem;color:var(--muted-dim);
  padding:0 10px;min-width:160px;
}
.peer-link .line{height:2px;background:repeating-linear-gradient(90deg,var(--blue) 0 6px,transparent 6px 11px);margin:8px 0}

.learn-grid{display:grid;grid-template-columns:1fr 1fr;gap:1px;background:var(--line);margin-top:26px;border:1px solid var(--line);border-radius:4px;overflow:hidden}
.learn-col{background:var(--panel-2);padding:18px 20px}
.learn-col h4{font-family:var(--mono);font-size:.78rem;color:var(--green);margin-bottom:10px;letter-spacing:.03em}
.learn-col ul{list-style:none}
.learn-col li{font-family:var(--mono);font-size:.85rem;color:var(--muted);padding:4px 0}
.learn-note{font-family:var(--mono);font-size:.76rem;color:var(--muted-dim);margin-top:14px}

/* ---------- Module / advantage cards ---------- */
.module{background:var(--panel);border:1px solid var(--line);border-radius:4px;padding:22px}
.module h3{font-family:var(--mono);font-size:.95rem;color:var(--amber);margin-bottom:10px;display:flex;align-items:center;gap:8px}
.module p{color:var(--muted);font-size:.9rem}

/* ---------- Comparison chips ---------- */
.chip-list{display:flex;flex-wrap:wrap;gap:10px;margin-top:18px}
.chip{
  font-family:var(--mono);font-size:.76rem;color:var(--blue);
  border:1px solid var(--blue-dim);padding:6px 12px;border-radius:20px;background:var(--panel);
}

/* ---------- Screenshot grid ---------- */
.shot{background:var(--panel);border:1px solid var(--line);border-radius:4px;padding:14px;overflow:hidden}
.shot img{border-radius:2px;border:1px solid var(--line-soft)}
.shot .cap{font-family:var(--mono);font-size:.74rem;color:var(--muted-dim);padding-top:10px}

/* ---------- Config diff (roadmap) ---------- */
.diff-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.diff-col{background:var(--panel);border:1px solid var(--line);border-radius:4px;padding:20px}
.diff-col .dc-hdr{
  font-family:var(--mono);font-size:.72rem;letter-spacing:.04em;text-transform:uppercase;
  padding-bottom:12px;border-bottom:1px solid var(--line-soft);margin-bottom:12px;
}
.diff-col.committed .dc-hdr{color:var(--green)}
.diff-col.pending .dc-hdr{color:var(--amber)}
.diff-line{font-family:var(--mono);font-size:.85rem;padding:5px 0;display:flex;gap:10px}
.diff-line .mark{flex-shrink:0}
.diff-col.committed .mark{color:var(--green)}
.diff-col.pending .mark{color:var(--amber)}
.diff-line .val{color:var(--muted)}

/* ---------- Lessons ---------- */
.lessons{display:grid;grid-template-columns:1fr 1fr;gap:6px 40px;max-width:980px}
.lesson-line{font-family:var(--mono);font-size:.86rem;color:var(--muted);padding:6px 0}
.lesson-line .hash{color:var(--muted-dim);margin-right:8px}

footer{
  text-align:center;padding:44px;color:var(--muted-dim);
  border-top:1px solid var(--line);font-family:var(--mono);font-size:.78rem;
  position:relative;z-index:1;
}
footer a{color:var(--amber);text-decoration:none}
footer a:hover{text-decoration:underline}

@media(max-width:900px){
  nav{padding:14px 6%}
  nav .links{gap:14px}
  header{padding:48px 6% 36px}
  section{padding:48px 6%}
  .learn-grid{grid-template-columns:1fr}
  .diff-grid{grid-template-columns:1fr}
  .lessons{grid-template-columns:1fr}
  .peer-row{flex-direction:column}
  .peer-link{transform:rotate(90deg);min-width:auto;padding:14px 0}
}

/* Lightbox */
.shot a{display:block;cursor:zoom-in}
.shot img{transition:.25s ease}
.shot:hover img{transform:scale(1.02);border-color:var(--amber)}
.lightbox{display:none;position:fixed;z-index:9999;left:0;top:0;width:100%;height:100%;background:rgba(0,0,0,.92);align-items:center;justify-content:center;padding:40px}
.lightbox img{max-width:95%;max-height:90%;border:2px solid var(--amber);border-radius:6px;box-shadow:0 0 40px rgba(0,0,0,.6)}
.lightbox .close{position:absolute;top:20px;right:30px;font-size:42px;color:#fff;cursor:pointer;font-family:Arial}

/* ===== Sprint 1 redesign ===== */

body{
 background:
 radial-gradient(circle at top,#17304f 0,#0a0d10 55%) fixed;
}
nav{
 backdrop-filter:blur(18px);
 border:1px solid rgba(255,255,255,.08);
 border-radius:18px;
 width:min(1200px,94%);
 margin:18px auto 0;
 left:0;right:0;
}
header{padding-top:120px;min-height:90vh}
.hero-bg{
 position:absolute;inset:0;
 background:
 radial-gradient(circle at 20% 10%,rgba(56,189,248,.18),transparent 30%),
 radial-gradient(circle at 80% 20%,rgba(255,176,32,.15),transparent 28%);
 z-index:-1;
}
.project-label{
 display:inline-block;
 letter-spacing:.25rem;
 color:#7dd3fc;
 font:700 .8rem var(--mono);
 margin-bottom:1rem;
}
.hero-small{
 font-size:1.2rem;
 color:#7dd3fc;
 letter-spacing:.2rem;
}
.hero-main{
 font-size:clamp(3.4rem,8vw,5.8rem);
 line-height:.95;
}
.hero-accent{color:var(--amber)}
.hero-panel{
 margin:2rem 0;
 max-width:700px;
 padding:22px;
 border:1px solid rgba(255,255,255,.08);
 background:rgba(255,255,255,.04);
 backdrop-filter:blur(18px);
 border-radius:20px;
 box-shadow:0 20px 60px rgba(0,0,0,.35);
}
.module,.route-card,.peer-wrap,.rack,.shot,.hoppanel{
 border-radius:18px;
 box-shadow:0 18px 40px rgba(0,0,0,.25);
 transition:.25s;
}
.module:hover,.route-card:hover,.shot:hover{
 transform:translateY(-6px);
 border-color:#38bdf8;
}
.btn{
 border-radius:999px;
}
.btn.primary{
 box-shadow:0 12px 30px rgba(255,176,32,.35);
}
.section-title{
 font-size:2.2rem;
}