/* The Cache & Edge Journal — network-diagram visual.
   Flat boxes, node/edge connector lines, blue links, sans typography, no rounded corners. */
:root {
  --bg: #f4f5f7;
  --panel: #ffffff;
  --ink: #1f2937;
  --muted: #64748b;
  --line: #d5dae2;
  --line-soft: #e4e8ee;
  --accent: #2563eb;
  --accent-dark: #1d4ed8;
  --cache: #2563eb;
  --case: #7c3aed;
  --lb: #0f766e;
  --perf: #b45309;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; }
body {
  font-family: -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.65;
  font-size: 16px;
}
.shell { max-width: 1100px; margin: 0 auto; padding: 0 20px; }
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-dark); text-decoration: underline; }

/* top bar — a flat node strip */
.topbar { background: var(--panel); border-bottom: 1px solid var(--line); }
.topbar-inner { display: flex; align-items: center; justify-content: space-between; padding: 15px 20px; }
.node-brand { display: flex; align-items: center; gap: 12px; color: var(--ink); }
.node-dot {
  width: 14px; height: 14px; background: var(--accent); display: inline-block; position: relative;
  box-shadow: 0 0 0 4px rgba(37, 99, 235, .12);
}
.node-dot::after {
  content: ""; position: absolute; right: -12px; top: 6px; width: 12px; height: 2px; background: var(--accent);
}
.node-text { display: flex; flex-direction: column; line-height: 1.2; margin-left: 6px; }
.node-name { font-weight: 700; letter-spacing: .2px; }
.node-tag { font-size: 11px; color: var(--muted); letter-spacing: .8px; text-transform: uppercase; }
.edge-nav { display: flex; gap: 20px; }
.edge-nav a { color: var(--ink); font-size: 14px; padding-bottom: 2px; border-bottom: 2px solid transparent; }
.edge-nav a:hover { border-bottom-color: var(--accent); text-decoration: none; }

/* hero + topology diagram */
.hero {
  background: var(--panel); border-bottom: 1px solid var(--line); padding: 44px 0;
  background-image: linear-gradient(var(--line-soft) 1px, transparent 1px),
                    linear-gradient(90deg, var(--line-soft) 1px, transparent 1px);
  background-size: 32px 32px;
}
.hero-kicker { color: var(--accent); font-size: 12px; letter-spacing: 2px; font-weight: 700; margin-bottom: 12px; }
.hero h1 { font-size: 34px; line-height: 1.15; font-weight: 700; margin-bottom: 14px; max-width: 760px; }
.hero-lede { max-width: 680px; color: var(--muted); font-size: 17px; }
.topology { display: flex; align-items: center; gap: 0; margin-top: 28px; flex-wrap: wrap; }
.topo-box {
  background: var(--panel); border: 1px solid var(--ink); padding: 12px 16px;
  display: flex; flex-direction: column; gap: 2px; min-width: 130px;
}
.topo-accent { border-color: var(--accent); border-width: 2px; }
.topo-role { font-size: 10px; letter-spacing: 1.4px; color: var(--muted); font-weight: 700; }
.topo-label { font-size: 15px; font-weight: 600; }
.topo-accent .topo-label { color: var(--accent-dark); }
.topo-edge { flex: 0 0 54px; height: 0; border-top: 2px dashed var(--accent); min-width: 30px; }

/* bands and key */
section { padding: 26px 0; }
.band-label { font-size: 12px; letter-spacing: 2px; text-transform: uppercase; color: var(--muted); margin-bottom: 16px; font-weight: 700; }
.layer-list { list-style: none; display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; }
.layer-list li { font-size: 14px; color: var(--ink); display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.policy-node {
  display: inline-block; font-size: 11px; font-weight: 700; letter-spacing: .6px; text-transform: uppercase;
  padding: 2px 9px; border: 1px solid currentColor; background: var(--panel);
}
.n-cache { color: var(--cache); }
.n-case { color: var(--case); }
.n-lb { color: var(--lb); }
.n-perf { color: var(--perf); }

/* topology node cards */
.topo-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.topo-node {
  position: relative; background: var(--panel); border: 1px solid var(--ink); padding: 16px 16px 16px 20px;
  display: flex; flex-direction: column; gap: 6px; color: var(--ink);
}
.topo-node:hover { border-color: var(--accent); border-width: 2px; padding: 15px 15px 15px 19px; text-decoration: none; }
.topo-port {
  position: absolute; left: -1px; top: 18px; width: 4px; height: 22px; background: currentColor;
}
.topo-node.n-cache .topo-port { background: var(--cache); }
.topo-node.n-case .topo-port { background: var(--case); }
.topo-node.n-lb .topo-port { background: var(--lb); }
.topo-node.n-perf .topo-port { background: var(--perf); }
.topo-count { font-size: 12px; color: var(--muted); }
.topo-name { font-weight: 700; font-size: 16px; }

/* clusters + policy grid */
.cluster-head { display: flex; align-items: baseline; justify-content: space-between; margin-bottom: 16px; }
.cluster-head h2 { font-size: 22px; font-weight: 700; }
.cluster-more { font-size: 13px; }
.policy-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.policy-card {
  position: relative; background: var(--panel); border: 1px solid var(--line); padding: 18px 16px;
  display: flex; flex-direction: column; gap: 10px; color: var(--ink);
}
.policy-card::before {
  content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 3px; background: var(--accent); opacity: .85;
}
.policy-card:hover { border-color: var(--accent); text-decoration: none; }
.policy-title { font-weight: 700; font-size: 16px; line-height: 1.3; }
.policy-ports { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; }
.port { display: flex; flex-direction: column; font-size: 13px; color: var(--ink); }
.port b { font-size: 10px; letter-spacing: .5px; text-transform: uppercase; color: var(--muted); font-weight: 700; margin-bottom: 1px; }
.policy-desc { font-size: 13px; color: var(--muted); }

/* page head */
.page-head { padding: 34px 0 10px; }
.crumb { font-size: 13px; color: var(--muted); margin-bottom: 8px; }
.crumb a { color: var(--muted); }
.page-head h1 { font-size: 30px; line-height: 1.2; font-weight: 700; }
.lede { color: var(--muted); margin-top: 8px; }

/* item layout — policy sheet + article */
.stack { display: grid; grid-template-columns: 320px 1fr; gap: 26px; padding-top: 22px; padding-bottom: 40px; align-items: start; }
.policy-sheet { background: var(--panel); border: 1px solid var(--ink); position: relative; }
.policy-sheet::before { content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 3px; background: var(--accent); }
.sheet-head { display: flex; align-items: center; justify-content: space-between; padding: 12px 14px; border-bottom: 1px solid var(--line); gap: 10px; }
.sheet-label { font-size: 11px; letter-spacing: 1px; text-transform: uppercase; color: var(--muted); font-weight: 700; }
.spec-list { font-variant-numeric: tabular-nums; }
.spec-row { display: flex; border-bottom: 1px solid var(--line-soft); font-size: 14px; }
.spec-row:last-child { border-bottom: 0; }
.spec-row dt { flex: 0 0 44%; padding: 9px 14px; color: var(--muted); border-right: 1px solid var(--line-soft); font-weight: 600; }
.spec-row dd { flex: 1; padding: 9px 14px; }
.article-body { background: var(--panel); border: 1px solid var(--line); padding: 26px 30px; }
.article-body .sec { margin-bottom: 24px; }
.article-body .sec:last-child { margin-bottom: 0; }
.article-body h2 { font-size: 19px; font-weight: 700; margin-bottom: 10px; display: flex; align-items: baseline; gap: 10px; }
.sec-num { color: var(--accent); font-variant-numeric: tabular-nums; font-size: 13px; border: 1px solid var(--accent); padding: 0 6px; }
.article-body p { margin-bottom: 12px; color: #2b3543; }
.article-body p:last-child { margin-bottom: 0; }
.article-body h2 { }
.related-list { list-style: none; margin: 0; padding: 0; }
.related-list li { padding: 7px 0; border-bottom: 1px solid var(--line-soft); }
.doc h2 { font-size: 18px; margin-top: 18px; }
.doc h2:first-child { margin-top: 0; }

/* bottom bar */
.bottombar { background: var(--panel); border-top: 1px solid var(--line); margin-top: 20px; padding: 30px 0; }
.bottombar-inner { display: flex; flex-wrap: wrap; gap: 20px; align-items: flex-start; }
.footer-brand { flex: 1 1 340px; }
.footer-brand p { color: var(--muted); font-size: 14px; margin-top: 6px; }
.footer-nav { display: flex; gap: 16px; }
.footer-nav a { color: var(--ink); font-size: 14px; }
.copyright { flex: 1 1 100%; font-size: 12px; color: var(--muted); margin-top: 10px; }

@media (max-width: 880px) {
  .topo-grid { grid-template-columns: repeat(2, 1fr); }
  .policy-grid { grid-template-columns: repeat(2, 1fr); }
  .layer-list { grid-template-columns: 1fr; }
  .stack { grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
  .topo-grid, .policy-grid { grid-template-columns: 1fr; }
  .topbar-inner { flex-direction: column; align-items: flex-start; gap: 10px; }
  .edge-nav { gap: 14px; }
  .hero h1 { font-size: 27px; }
  .topology { gap: 8px 0; }
  .topo-edge { flex: 0 0 26px; }
}