/* Shared design language with the rest of the portfolio (it-job-radar): the palette is a set
   of variables and dark mode swaps the variables rather than restating the design. The
   diagram is inline SVG for the same reason — it inherits these colours instead of shipping
   a second, hard-coded palette baked into an image. */
:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --surface: #f6f8fa;
  --border: #e3e7ee;
  /* The control boundary. SC 1.4.11 asks 3:1 of it and --border gives 1.17:1;
     this is 3.27:1 on --surface, the binding ground of the two. */
  --border-control: #808a9c;
  --text: #1c2430;
  --muted: #5b6472;
  --accent: #2563eb;
  --accent-soft: #5b93e4;  /* 3.12:1 on --bg; #93c5fd was 1.80:1, under the 3:1 a mark needs */
  /* This page is the one that paints --positive as body text - .ledger td.probe-ok and
     .verdict .ok, both outside every card, so the ground is --bg. #059669 measured 3.77:1
     against AA's 4.5:1 for text this size; #047857 is 5.48:1. */
  --positive: #047857;
  --warn: #b45309;
  --violet: #7c3aed;
  --slate: #64748b;
  --radius: 10px;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1319;
    --surface: #161c25;
    --border: #263041;
    --border-control: #596a89;  /* 3.14:1 on --surface; --border is 1.29:1 */
    --text: #e6eaf2;
    --muted: #98a3b6;
    --accent: #6ea8fe;
    --accent-soft: #4167a6;  /* 3.30:1 on the dark page; #2c4a7c was 2.11:1 */
    --positive: #34d399;
    --warn: #fbbf24;
    --violet: #a78bfa;
    --slate: #94a3b8;
  }
}

* { box-sizing: border-box; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue",
    Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  max-width: 62rem;
  margin: 0 auto;
  padding: 2.5rem 1.25rem 4rem;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

a { color: var(--accent); }
a:focus-visible, summary:focus-visible, button:focus-visible,
input:focus-visible, select:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 3px;
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--muted);
  margin: 0 0 0.5rem;
}

h1 {
  font-size: clamp(1.75rem, 1.2rem + 2.2vw, 2.75rem);
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin: 0 0 0.75rem;
}

h2 {
  font-size: 1.3rem;
  letter-spacing: -0.01em;
  margin: 2.75rem 0 0.35rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

h2:first-of-type { border-top: none; padding-top: 0; }
h3 { font-size: 1rem; margin: 1.5rem 0 0.25rem; }
p { margin: 0.5rem 0; }
.lead { font-size: 1.1rem; color: var(--muted); max-width: 46rem; }
.note { color: var(--muted); font-size: 0.9rem; }
.hint { display: block; color: var(--muted); font-size: 0.85rem; font-weight: 400; }

.kpis {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(11rem, 1fr));
  gap: 0.75rem;
  margin: 1.75rem 0;
  padding: 0;
  list-style: none;
}

.kpi {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.9rem 1rem;
}

.kpi-value { font-size: 1.6rem; font-weight: 700; letter-spacing: -0.02em; }
.kpi-label { font-size: 0.85rem; font-weight: 600; }
.kpi-note { font-size: 0.78rem; color: var(--muted); line-height: 1.35; }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.2rem;
  margin: 1.25rem 0;
}

.card.caution { border-left: 3px solid var(--warn); }

figure { margin: 1rem 0 0; }
figcaption { color: var(--muted); font-size: 0.85rem; margin-top: 0.35rem; }

/* Wide content scrolls inside its own box; the page itself never scrolls sideways. */
.scroll-x { overflow-x: auto; }

table { border-collapse: collapse; width: 100%; font-size: 0.92rem; }
th, td { text-align: left; padding: 0.4rem 0.6rem; border-bottom: 1px solid var(--border); }
th { font-weight: 600; color: var(--muted); font-size: 0.82rem; }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; }
td.mono, th.mono { font-family: var(--mono); font-size: 0.85em; }

details { margin: 0.75rem 0; }
summary { cursor: pointer; font-size: 0.9rem; color: var(--accent); }
pre {
  overflow-x: auto;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.85rem 1rem;
  font-size: 0.8rem;
  line-height: 1.5;
  font-family: var(--mono);
}
code { font-size: 0.9em; font-family: var(--mono); }

footer {
  margin-top: 3rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.85rem;
}

/* ---------------------------------------------------------------- simulator controls */

.controls {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(12rem, 1fr));
  gap: 0.75rem 1.1rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.2rem;
  margin: 1.25rem 0 0.75rem;
}

.field { display: flex; flex-direction: column; gap: 0.15rem; min-width: 0; }
.field > label { font-size: 0.82rem; font-weight: 600; }
.field .flag { font-family: var(--mono); font-weight: 400; color: var(--muted); }

.field select, .field input[type="range"] { width: 100%; }

.field select, .field input[type="number"] {
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border-control);
  border-radius: 6px;
  padding: 0.35rem 0.4rem;
  font: inherit;
  font-size: 0.9rem;
}

.field input[type="range"] { accent-color: var(--accent); margin: 0.35rem 0 0; }
.field output { font-family: var(--mono); font-size: 0.85rem; color: var(--muted); }

.transport { display: flex; flex-wrap: wrap; gap: 0.5rem; align-items: center; margin: 0.75rem 0; }

button {
  font: inherit;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--bg);
  background: var(--accent);
  border: 1px solid var(--accent);
  border-radius: 6px;
  padding: 0.35rem 0.9rem;
  cursor: pointer;
}

button.secondary { background: transparent; color: var(--accent); }
button:disabled { opacity: 0.45; cursor: not-allowed; }

.errors {
  color: var(--warn);
  font-size: 0.88rem;
  font-family: var(--mono);
  margin: 0.5rem 0;
  white-space: pre-line;
}
.errors:empty { display: none; }

.checkbox { flex-direction: row; align-items: center; gap: 0.45rem; align-self: end; }
.checkbox input { accent-color: var(--accent); }

/* ---------------------------------------------------------------- path diagram */

.diagram { display: block; }
.diagram text { font-size: 11px; fill: var(--text); }
.diagram .lane { stroke: var(--border); stroke-width: 2; }
.diagram .node { fill: var(--bg); stroke: var(--slate); stroke-width: 2; }
.diagram .node.endpoint { stroke: var(--text); }
.diagram .node.active { stroke: var(--accent); fill: var(--accent-soft); }
.diagram .node.replied { stroke: var(--positive); }
.diagram .node.silent { stroke: var(--warn); stroke-dasharray: 3 3; }
/* Beyond --max-hops: still on the path, but this run will never send a probe that far. */
.diagram .node.out-of-range { opacity: 0.32; }
.diagram .node-label { font-size: 10px; fill: var(--muted); text-anchor: middle; }
.diagram .node-addr { font-size: 10px; fill: var(--text); text-anchor: middle; font-family: var(--mono); }
.diagram .node-index { font-size: 10px; fill: var(--muted); text-anchor: middle; font-weight: 600; }
.diagram .probe { fill: var(--accent); }
.diagram .probe-ttl { fill: var(--bg); font-size: 9px; font-weight: 700; text-anchor: middle; }
.diagram .reply { fill: var(--positive); }
.diagram .reply.final { fill: var(--violet); }
.diagram .expiry { stroke: var(--warn); stroke-width: 2.5; stroke-linecap: round; }
.diagram .caption { font-size: 11px; fill: var(--muted); }

/* ---------------------------------------------------------------- terminal + ledger */

.terminal {
  min-height: 9rem;
  white-space: pre;
  tab-size: 4;
}

.terminal .cursor { background: var(--accent); color: var(--bg); }

/* `0007` §5 clause 3: every table sits in `.table-wrap`, which computes to `overflow-x: auto`.
   The house name carries the scrolling; `.ledger-wrap` is left holding only what is peculiar
   to the ledger — a height cap with sticky headers inside a bordered box — so the second
   table can take the wrapper without inheriting a look that is not its own. */
.table-wrap { overflow-x: auto; }
.ledger-wrap { max-height: 20rem; overflow-y: auto; border: 1px solid var(--border); border-radius: var(--radius); }
.ledger { font-size: 0.86rem; }
.ledger thead th { position: sticky; top: 0; background: var(--bg); }
.ledger td.probe-ok { color: var(--positive); font-weight: 600; }
.ledger td.probe-miss { color: var(--warn); font-weight: 700; }
.ledger td.note { color: var(--muted); font-size: 0.8rem; }
tr.matched { background: color-mix(in srgb, var(--accent-soft) 28%, transparent); }

/* ---------------------------------------------------------------- packet anatomy */

.hexdump {
  font-family: var(--mono);
  font-size: 0.78rem;
  line-height: 1.9;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.85rem 1rem;
  min-width: 30rem;
}

.hexdump .row { white-space: pre; }
.hexdump .off { color: var(--muted); }

/* Field identity is carried by a background tint, but every byte also belongs to a named row
   in the table below — colour is a second reading, never the only one. */
.b { padding: 0.1rem 0.15rem; border-radius: 2px; }
.b-outer { background: color-mix(in srgb, var(--slate) 22%, transparent); }
.b-icmp { background: color-mix(in srgb, var(--accent) 22%, transparent); }
.b-inner { background: color-mix(in srgb, var(--violet) 22%, transparent); }
.b-udp { background: color-mix(in srgb, var(--positive) 22%, transparent); }
.b-dport {
  background: color-mix(in srgb, var(--warn) 38%, transparent);
  outline: 1.5px solid var(--warn);
  font-weight: 700;
}

.legend { display: flex; flex-wrap: wrap; gap: 0.35rem 1rem; list-style: none; padding: 0; margin: 0.6rem 0 0; font-size: 0.82rem; color: var(--muted); }
.legend li { display: flex; align-items: center; gap: 0.35rem; }
.swatch { width: 0.8rem; height: 0.8rem; border-radius: 3px; display: inline-block; }
.swatch.s-outer { background: color-mix(in srgb, var(--slate) 45%, transparent); }
.swatch.s-icmp { background: color-mix(in srgb, var(--accent) 45%, transparent); }
.swatch.s-inner { background: color-mix(in srgb, var(--violet) 45%, transparent); }
.swatch.s-udp { background: color-mix(in srgb, var(--positive) 45%, transparent); }
.swatch.s-dport { background: color-mix(in srgb, var(--warn) 55%, transparent); outline: 1.5px solid var(--warn); }

.verdict { font-family: var(--mono); font-size: 0.85rem; margin: 0.75rem 0 0; }
.verdict .ok { color: var(--positive); font-weight: 700; }
.verdict .no { color: var(--warn); font-weight: 700; }

.empty { color: var(--muted); font-size: 0.9rem; font-style: italic; }

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}

@media print {
  body { max-width: none; }
  details, .controls, .transport { display: none; }
}