:root {
  --dg-default: #7b8794;   /* grey — default-route ribbons */
  --dg-localpref: #2e7d32; /* green — full-table ribbons (echoes the LPP report) */
  --dg-unreached: #c62828; /* red — the ✗ unreached anchor */
  --dg-covering: #d4a017;  /* amber — covering-route ASes (create the gap) */
  --dg-node: #8aa0b2;      /* slate — VP / transit ASes */
  --dg-bg: #fff;
  --dg-ink: #1f2933;
  --dg-muted: #647280;
  --dg-line: #e2e8f0;
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
body { margin: 0; font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  color: var(--dg-ink); background: var(--dg-bg); }
.dg-header { position: relative; padding: 18px 24px 10px; border-bottom: 1px solid var(--dg-line); }
.dg-header-actions { position: absolute; top: 16px; right: 24px; display: flex; gap: 8px; }
.dg-about-btn { cursor: pointer;
  border: 1px solid var(--dg-line); background: #f8fafc; color: var(--dg-ink);
  border-radius: 6px; padding: 5px 14px; font: inherit; font-size: 13px; }
.dg-about-btn:hover { background: #eef2f6; border-color: var(--dg-localpref); }
.dg-about { max-width: 760px; }
.dg-about-body { font-size: 13px; line-height: 1.5; color: var(--dg-ink); }
.dg-about-body h4 { font-size: 13px; margin: 14px 0 4px; }
.dg-about-body p { margin: 0 0 8px; }
.dg-about-body ul { margin: 0 0 8px; padding-left: 20px; }
.dg-about-body li { margin: 2px 0; }
.dg-about-body code { background: #f1f5f9; padding: 0 4px; border-radius: 3px; }
.dg-header h1 { font-size: 20px; margin: 0 0 4px; }
.dg-sub { margin: 0; color: var(--dg-muted); font-size: 13px; max-width: 70ch; }
.dg-legend { padding: 1px 6px; border-radius: 4px; color: #fff; font-size: 12px; }
.dg-default { background: var(--dg-default); }
.dg-localpref { background: var(--dg-localpref); }
.dg-layout { display: flex; min-height: calc(100vh - 70px); }
.dg-rail { width: 280px; flex: 0 0 280px; border-right: 1px solid var(--dg-line);
  overflow-y: auto; padding: 8px; }
.dg-rail-item { display: block; width: 100%; text-align: left; border: 1px solid transparent;
  background: none; padding: 8px 10px; border-radius: 6px; cursor: pointer; font: inherit; }
.dg-rail-item:hover { background: #f1f5f9; }
.dg-rail-item.active { background: #e8f0f4; border-color: var(--dg-localpref); }
.dg-rail-prefix { font-weight: 600; font-size: 13px; }
.dg-rail-covering { font-size: 11px; color: var(--dg-muted); margin-top: 1px; }
.dg-rail-origins { font-size: 11px; color: var(--dg-muted); margin-top: 1px; }
.dg-main { flex: 1; padding: 14px 20px; overflow: auto; }

/* In-body intro block (repeats the gist of the About page) + prominent CTA. */
.dg-intro { display: flex; gap: 16px; align-items: flex-start;
  justify-content: space-between; background: #f8fafc; border: 1px solid var(--dg-line);
  border-radius: 8px; padding: 12px 16px; margin-bottom: 12px; }
.dg-intro-text { font-size: 13px; line-height: 1.5; max-width: 82ch; }
.dg-intro-text p { margin: 0 0 6px; }
.dg-intro-text p:last-child { margin-bottom: 0; }
.dg-intro-legend { color: var(--dg-muted); }
.dg-about-cta { flex: 0 0 auto; cursor: pointer; border: 1px solid var(--dg-localpref);
  background: #fff; color: var(--dg-localpref); border-radius: 6px; padding: 8px 14px;
  font: inherit; font-size: 13px; font-weight: 600; white-space: nowrap; }
.dg-about-cta:hover { background: var(--dg-localpref); color: #fff; }

/* Landing overview: the thorough explanation shown when no prefix is selected. */
.dg-overview { max-width: 80ch; font-size: 14px; line-height: 1.55; }
.dg-overview h2 { font-size: 18px; margin: 4px 0 10px; }
.dg-overview h3 { font-size: 14px; margin: 16px 0 4px; }
.dg-overview p { margin: 0 0 10px; }
.dg-overview ul { margin: 0 0 10px; padding-left: 20px; }
.dg-overview li { margin: 3px 0; }
.dg-overview .dg-legend { color: #fff; }
.dg-overview-prompt { margin-top: 16px; padding: 10px 14px; border-radius: 8px;
  background: #f1f7f2; border: 1px solid #cde6d2; color: #22543d; font-weight: 600; }
.dg-overview-prompt.empty { background: #fef2f2; border-color: #f3c9c9; color: #7c2222; }

/* Per-prefix lineage table (more-specific up through every covering parent). */
.dg-lineage { margin-bottom: 12px; }
.dg-lineage-head { display: flex; align-items: baseline; gap: 12px; margin-bottom: 6px; }
.dg-lineage-head b { font-size: 14px; color: var(--dg-ink); }
.dg-lineage-counts { font-size: 12px; color: var(--dg-muted); }
.dg-lineage-table { border-collapse: collapse; width: 100%; font-size: 12px; }
.dg-lineage-table th { text-align: left; color: var(--dg-muted); font-weight: 600;
  padding: 2px 12px 4px 0; border-bottom: 1px solid var(--dg-line); }
.dg-lineage-table td { padding: 3px 12px 3px 0; vertical-align: top;
  font-variant-numeric: tabular-nums; }
.dg-lineage-table tr.dg-lineage-group td { border-top: 1px solid var(--dg-line); }
.dg-lineage-pfx { white-space: nowrap; }
.dg-lineage-pfxtext { font-weight: 600; }
.dg-aspath { color: var(--dg-ink); }
.dg-comm { display: inline-block; background: #f1f5f9; border-radius: 3px;
  padding: 0 5px; margin: 0 3px 3px 0; font-size: 11px; color: var(--dg-muted); }
.dg-tag { display: inline-block; margin-left: 6px; padding: 0 6px; border-radius: 8px;
  font-size: 10px; font-weight: 600; vertical-align: middle; }
.dg-tag.tag-specific { background: #fde68a; color: #7c5e10; }
.dg-tag.tag-re { background: #c6f6d5; color: #22543d; }
.dg-tag.tag-comm { background: #e2e8f0; color: #475569; }
.dg-graph { width: 100%; }
.dg-graph svg { max-width: 100%; height: auto; }
/* Node fill by role. Order matters: later rules win specificity ties, so an
   AS that is both covering and origin reads as origin (green). */
.dg-node rect { fill: var(--dg-node); stroke: #fff; stroke-width: 1; } /* VP / transit */
.dg-node text { font-size: var(--dg-label-font, 11px); fill: var(--dg-ink); }
.dg-node.role-covering rect { fill: var(--dg-covering); }
.dg-node.role-vp rect { stroke: #5a6b7b; stroke-width: 1.5; }
.dg-node.role-origin rect { fill: var(--dg-localpref); stroke: #1b5e20; stroke-width: 2; }
.dg-node.role-reached rect { fill: var(--dg-localpref); stroke: #1b5e20; stroke-width: 2; }
.dg-node.role-sink rect { fill: var(--dg-unreached); stroke: #8e1a1a; stroke-width: 2; }

/* On-canvas legend: ribbon key + node-colour key. */
.dg-graph-legend { display: flex; flex-wrap: wrap; gap: 8px 22px; margin: 0 0 10px;
  font-size: 12px; color: var(--dg-muted); }
.dg-leg-group { display: flex; flex-wrap: wrap; align-items: center; gap: 4px 12px; }
.dg-leg-title { font-weight: 600; color: var(--dg-ink); }
.dg-leg-item { display: inline-flex; align-items: center; gap: 5px; }
.dg-leg-sw { width: 14px; height: 10px; border-radius: 2px; display: inline-block; }
.dg-leg-sw.leg-localpref { background: var(--dg-localpref); }
.dg-leg-sw.leg-default { background: var(--dg-default); }
.dg-leg-sw.leg-origin { background: var(--dg-localpref); }
.dg-leg-sw.leg-covering { background: var(--dg-covering); }
.dg-leg-sw.leg-vp { background: var(--dg-node); }
.dg-leg-sw.leg-sink { background: var(--dg-unreached); }
.dg-link { opacity: 0.78; }
.dg-link:hover { opacity: 1; }
/* Ribbon selection: clicking one ribbon greys out the others. */
.dg-link.dg-dimmed { stroke: #c4ccd4; opacity: 0.4; }
.dg-link.dg-selected { opacity: 1; }
.dg-hint { font-size: 12px; color: var(--dg-muted); margin: 0 0 8px; }
/* Display controls (AS label size). */
.dg-controls { display: flex; align-items: center; gap: 8px; margin: 0 0 10px;
  font-size: 12px; color: var(--dg-muted); }
.dg-ctrl-label { font-weight: 600; color: var(--dg-ink); }
.dg-slider { width: 130px; accent-color: var(--dg-localpref); cursor: pointer; }
.dg-ctrl-val { font-variant-numeric: tabular-nums; min-width: 32px; }
/* Hop-by-hop trace detail, shown in an overlay modal. */
.dg-modal { position: fixed; inset: 0; z-index: 1000; display: flex;
  align-items: center; justify-content: center; background: rgba(15, 23, 33, 0.45); }
.dg-modal[hidden] { display: none; }
.dg-modal-box { background: var(--dg-bg); border-radius: 8px;
  box-shadow: 0 12px 44px rgba(0, 0, 0, 0.28); max-width: 860px; width: 90%;
  max-height: 82vh; overflow: auto; padding: 16px 20px; }
.dg-detail { font-size: 12px; }
.dg-detail-head { display: flex; align-items: baseline; justify-content: space-between; }
.dg-detail-head h3 { font-size: 13px; margin: 0 0 8px; }
.dg-detail-close { cursor: pointer; border: 1px solid var(--dg-line); background: #f8fafc;
  border-radius: 4px; padding: 2px 8px; font: inherit; }
.dg-vp { margin: 0 0 14px; }
.dg-vp-head { font-weight: 600; margin-bottom: 3px; }
.dg-vp-head .reached { color: #1b5e20; }
.dg-vp-head .unreached { color: var(--dg-unreached); font-weight: 600; }
.dg-hops { border-collapse: collapse; width: 100%; max-width: 760px; }
.dg-hops th, .dg-hops td { text-align: left; padding: 2px 10px 2px 0;
  border-bottom: 1px solid #f0f3f6; font-variant-numeric: tabular-nums; }
.dg-hops th { color: var(--dg-muted); font-weight: 600; }
.dg-hops td.masked { color: var(--dg-muted); font-style: italic; }

/* Snapshot picker + data-sources panel */
.dg-snapshot-picker {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.dg-snapshot-label {
  color: var(--dg-muted);
  font-size: 12px;
}
.dg-snapshot-picker select {
  font: inherit;
  font-size: 13px;
  color: var(--dg-ink);
  background: #f8fafc;
  border: 1px solid var(--dg-line);
  border-radius: 6px;
  padding: 3px 6px;
}
.dg-source-primary {
  border: 1px solid var(--dg-line);
  border-radius: 8px;
  background: #f8fafc;
  padding: 10px 14px;
  margin: 0 0 14px;
}
.dg-source-primary h4 { margin: 0 0 4px; font-size: 0.95rem; color: var(--dg-localpref); }
.dg-source-primary p { margin: 0; }
.dg-source-primary .dg-source-stats {
  margin-top: 4px;
  color: var(--dg-muted);
  font-size: 12px;
  font-variant-numeric: tabular-nums;
}
.dg-source-intro { margin: 0 0 8px; color: var(--dg-muted); }
.dg-source-links { margin: 0; padding-left: 20px; line-height: 1.5; color: var(--dg-ink); }
.dg-source-links li { margin: 0 0 7px; }