/* WTF is RFID? — same palette as the rfid.wtf landing page (always dark). */
:root {
  color-scheme: dark;
  --bg: #0d1117;
  --fg: #e6edf3;
  --muted: #8b949e;
  --accent: #58d6ff;
  --card: #161b22;
  --card-2: #1c232c;
  --border: #30363d;
  --lf: #f0b35a;
  --hf: #58d6ff;
  --uhf: #c792ea;
  --any: #8b949e;
  --ok: #3fb950;
  --warn: #f0b35a;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
}
* { box-sizing: border-box; }
html { scroll-padding-top: 1rem; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  line-height: 1.6;
  min-height: 100svh;
  display: flex;
  flex-direction: column;
}
a { color: var(--accent); }
main, .topbar, .foot { width: 100%; max-width: 46rem; margin: 0 auto; padding: 0 1rem; }
main { flex: 1; }

/* top bar */
.topbar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding-top: 1.25rem;
  padding-bottom: 1.25rem;
  font-family: var(--mono);
}
.topbar a { color: var(--fg); text-decoration: none; }
.topbar .home { font-weight: 700; }
.topbar .tld { color: var(--accent); }
.topbar .sep { color: var(--muted); }
.topbar .home-learn:hover, .topbar .home:hover { color: var(--accent); }
.copy-link {
  margin-left: auto;
  font: inherit;
  font-size: 0.8rem;
  color: var(--muted);
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.3rem 0.65rem;
  cursor: pointer;
}
.copy-link:hover { color: var(--fg); border-color: var(--accent); }
.copy-link.done { color: var(--ok); border-color: var(--ok); }

/* trail */
.trail {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 0.4rem;
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--muted);
}
.trail a { color: var(--muted); text-decoration: none; }
.trail a:hover { color: var(--accent); }
.trail > * + *::before { content: "›"; margin-right: 0.4rem; color: var(--border); }
.trail span { color: var(--fg); }

/* badges / chips / cards */
.badges { margin-top: 1.25rem; display: flex; flex-wrap: wrap; gap: 0.4rem; }
.badge {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  color: var(--muted);
}
.badge.band-lf { color: var(--lf); border-color: color-mix(in srgb, var(--lf) 45%, transparent); }
.badge.band-hf { color: var(--hf); border-color: color-mix(in srgb, var(--hf) 45%, transparent); }
.badge.band-uhf { color: var(--uhf); border-color: color-mix(in srgb, var(--uhf) 45%, transparent); }

.chips { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.chip {
  --c: var(--any);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.3rem 0.7rem;
  border-radius: 999px;
  background: var(--card);
  border: 1px solid var(--border);
  border-left: 3px solid var(--c);
  color: var(--fg);
  text-decoration: none;
  font-size: 0.9rem;
}
.chip:hover { border-color: var(--c); }
.band-lf { --c: var(--lf); }
.band-hf { --c: var(--hf); }
.band-uhf { --c: var(--uhf); }
.band-any { --c: var(--any); }
.seen::after {
  content: "✓";
  color: var(--ok);
  font-size: 0.85em;
  font-weight: 700;
}

.cards { display: grid; gap: 0.75rem; padding: 0; margin: 0; list-style: none; }
.card {
  position: relative;
  display: block;
  padding: 0.9rem 1.1rem;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--fg);
  text-decoration: none;
  transition: border-color 0.15s ease;
}
.card:hover { border-color: var(--accent); }
.card-title { display: block; font-weight: 600; color: var(--accent); }
.card-summary { display: block; margin-top: 0.2rem; font-size: 0.9rem; color: var(--muted); }
.card-badges { display: flex; gap: 0.35rem; margin-top: 0.6rem; flex-wrap: wrap; }
.card.seen::after { position: absolute; top: 0.8rem; right: 1rem; }

/* node page */
.node h1 { font-size: clamp(1.9rem, 6vw, 2.6rem); line-height: 1.15; margin: 0.6rem 0 0; letter-spacing: -0.01em; }
.lede { font-size: 1.1rem; color: var(--muted); margin: 0.6rem 0 0; }
.builds-on {
  margin-top: 1.25rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 0.9rem;
  border: 1px dashed var(--border);
  border-radius: 10px;
}
.builds-on-label { font-size: 0.8rem; color: var(--muted); margin-right: 0.25rem; }
.builds-on.unread { border-color: var(--warn); }
.builds-on.unread .builds-on-label::after { content: " — you haven't read these yet"; color: var(--warn); }

.prose { margin-top: 1.5rem; }
.prose h2, .prose h3, .prose h4 { position: relative; line-height: 1.3; margin: 2rem 0 0.5rem; }
.prose h2 { font-size: 1.35rem; }
.prose h3 { font-size: 1.1rem; }
.prose .anchor {
  position: absolute;
  left: -1.1rem;
  color: var(--border);
  text-decoration: none;
  opacity: 0;
  font-weight: 400;
}
.prose :is(h2, h3, h4):hover .anchor, .prose .anchor:focus { opacity: 1; }
.prose p, .prose ul, .prose ol { margin: 0.8rem 0; }
.prose li + li { margin-top: 0.25rem; }
.prose code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: var(--card-2);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.05rem 0.3rem;
}
.prose pre {
  overflow-x: auto;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.9rem 1rem;
  font-size: 0.85rem;
  line-height: 1.45;
}
.prose pre code { background: none; border: 0; padding: 0; }
.prose table { width: 100%; border-collapse: collapse; font-size: 0.9rem; margin: 1rem 0; display: block; overflow-x: auto; }
.prose th, .prose td { text-align: left; padding: 0.45rem 0.6rem; border-bottom: 1px solid var(--border); vertical-align: top; }
.prose th { color: var(--muted); font-weight: 600; white-space: nowrap; }
.prose blockquote { margin: 1rem 0; padding-left: 1rem; border-left: 3px solid var(--border); color: var(--muted); }
.prose img { max-width: 100%; }

/* inline refs + peeks */
a.ref {
  color: var(--fg);
  text-decoration: underline dotted var(--accent);
  text-underline-offset: 3px;
  text-decoration-thickness: 2px;
}
a.ref:hover, a.ref[aria-expanded="true"] { color: var(--accent); }
a.ref.seen::after { content: none; }
.peek {
  margin: 0.5rem 0 1rem;
  padding: 0.8rem 1rem;
  background: var(--card-2);
  border: 1px solid var(--border);
  border-left: 3px solid var(--c, var(--accent));
  border-radius: 8px;
  font-size: 0.92rem;
  animation: peek-in 0.15s ease-out;
}
@keyframes peek-in { from { opacity: 0; transform: translateY(-4px); } }
.peek-head { display: flex; align-items: baseline; gap: 0.5rem; }
.peek-title { font-weight: 600; }
.peek-close {
  margin-left: auto;
  background: none;
  border: 0;
  color: var(--muted);
  font-size: 1.1rem;
  cursor: pointer;
  line-height: 1;
}
.peek-close:hover { color: var(--fg); }
.peek p { margin: 0.3rem 0 0.5rem; color: var(--muted); }
.peek-go { font-size: 0.85rem; font-family: var(--mono); }

/* callouts */
.callout {
  margin: 1.25rem 0;
  padding: 0.8rem 1rem;
  border-radius: 8px;
  background: var(--card);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
}
.callout > :first-child, .callout > .callout-label + * { margin-top: 0.25rem; }
.callout > :last-child { margin-bottom: 0; }
.callout-label {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
}
.callout-try { border-left-color: var(--ok); }
.callout-try .callout-label { color: var(--ok); }
.callout-try .callout-label::before { content: "👉 "; }
.callout-myth { border-left-color: var(--uhf); }
.callout-myth .callout-label { color: var(--uhf); }
.callout-myth .callout-label::before { content: "🙅 "; }
.callout-warning { border-left-color: var(--warn); }
.callout-warning .callout-label { color: var(--warn); }
.callout-weeds { border-left-color: var(--muted); }
.callout-weeds summary {
  cursor: pointer;
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--muted);
}
.callout-weeds summary:hover { color: var(--fg); }
.callout-weeds[open] summary { margin-bottom: 0.5rem; }

/* sections after the article */
.where-next, .used-by { margin-top: 2.5rem; }
.where-next h2, .used-by h2, .map h2, .track h2 {
  font-family: var(--mono);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
  margin: 0 0 0.75rem;
}

/* hub */
.hub-hero h1 {
  font-family: var(--mono);
  font-size: clamp(2.2rem, 9vw, 3.4rem);
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin: 0.5rem 0 0;
}
.progress { font-family: var(--mono); font-size: 0.85rem; color: var(--ok); margin: 0.75rem 0 0; }
.tracks { margin-top: 2.25rem; display: grid; gap: 2rem; }
.track-desc { margin: -0.4rem 0 0.9rem; color: var(--muted); font-size: 0.92rem; }
.track ol.cards { counter-reset: step; }
.track ol.cards > li { counter-increment: step; }
.track ol.cards .card-title::before {
  content: counter(step) ". ";
  color: var(--muted);
  font-family: var(--mono);
}
.map { margin-top: 3rem; }
.map-band + .map-band { margin-top: 1.25rem; }
.map-band h3 { font-family: var(--mono); font-size: 0.8rem; font-weight: 600; margin: 0 0 0.5rem; color: var(--c); }
.track .cards { grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr)); }

.foot {
  margin-top: 4rem;
  padding-top: 1.5rem;
  padding-bottom: 2rem;
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--muted);
}
.foot a { color: var(--muted); }

/* ---- widgets ------------------------------------------------------------ */
.widget {
  margin: 1.5rem 0;
  padding: 1rem;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 0.92rem;
}
.widget .w-title {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.75rem;
}
.widget .w-title::before { content: "⚡ "; }
.widget input[type="range"] { width: 100%; accent-color: var(--accent); }
.widget input[type="number"], .widget input[type="text"], .widget select {
  font: inherit;
  font-family: var(--mono);
  color: var(--fg);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.35rem 0.5rem;
  width: 100%;
  min-width: 0;
}
.widget input:focus, .widget select:focus { outline: none; border-color: var(--accent); }
.widget label { display: block; font-size: 0.78rem; color: var(--muted); margin-bottom: 0.25rem; }
.widget .w-row { display: grid; gap: 0.75rem; grid-template-columns: repeat(auto-fit, minmax(9rem, 1fr)); }
.widget .w-presets { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-top: 0.6rem; }
.widget button.w-btn {
  font: inherit;
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--fg);
  background: var(--card-2);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.25rem 0.7rem;
  cursor: pointer;
}
.widget button.w-btn:hover, .widget button.w-btn[aria-pressed="true"] { border-color: var(--accent); color: var(--accent); }
.widget .w-stats { display: grid; gap: 0.5rem; grid-template-columns: repeat(auto-fit, minmax(8.5rem, 1fr)); margin-top: 0.9rem; }
.widget .w-stat { background: var(--bg); border: 1px solid var(--border); border-radius: 8px; padding: 0.5rem 0.65rem; }
.widget .w-stat b { display: block; font-family: var(--mono); font-size: 1.05rem; color: var(--fg); font-weight: 600; }
.widget .w-stat span { font-size: 0.75rem; color: var(--muted); }
.widget .w-note { margin-top: 0.8rem; color: var(--muted); line-height: 1.5; }
.widget .w-note strong { color: var(--fg); }
.widget svg { display: block; width: 100%; height: auto; margin-top: 0.75rem; }
.widget .w-bits { display: flex; flex-wrap: wrap; gap: 3px; margin-top: 0.9rem; font-family: var(--mono); }
.widget .w-bit {
  width: 1.45rem;
  text-align: center;
  padding: 0.2rem 0;
  border-radius: 4px;
  background: var(--bg);
  border: 1px solid var(--border);
  font-size: 0.85rem;
}
.widget .w-bit.parity { border-color: var(--warn); color: var(--warn); }
.widget .w-bit.fc { border-color: var(--uhf); color: var(--uhf); }
.widget .w-bit.cn { border-color: var(--hf); color: var(--hf); }
.widget .w-legend { display: flex; flex-wrap: wrap; gap: 0.9rem; margin-top: 0.6rem; font-size: 0.78rem; color: var(--muted); }
.widget .w-legend i { display: inline-block; width: 0.7rem; height: 0.7rem; border-radius: 3px; margin-right: 0.3rem; vertical-align: -1px; border: 2px solid var(--c); }
.widget .w-mono { font-family: var(--mono); word-break: break-all; }
.widget .w-out { margin-top: 0.75rem; padding: 0.6rem 0.75rem; background: var(--bg); border: 1px solid var(--border); border-radius: 8px; }

/* mifare map */
.w-mf { display: grid; grid-template-columns: repeat(4, 1fr); gap: 4px; margin-top: 0.5rem; }
@media (min-width: 34rem) { .w-mf { grid-template-columns: repeat(8, 1fr); } }
.w-mf-sector { display: grid; gap: 2px; padding: 3px; border: 1px solid var(--border); border-radius: 6px; }
.w-mf-sector .s-no { font-family: var(--mono); font-size: 0.62rem; color: var(--muted); text-align: center; }
.w-mf-block {
  height: 0.9rem;
  border-radius: 2px;
  border: 0;
  padding: 0;
  cursor: pointer;
  background: color-mix(in srgb, var(--hf) 30%, var(--bg));
}
.w-mf-block.trailer { background: color-mix(in srgb, var(--warn) 55%, var(--bg)); }
.w-mf-block.mfr { background: color-mix(in srgb, var(--uhf) 60%, var(--bg)); }
.w-mf-block:hover, .w-mf-block[aria-pressed="true"] { outline: 2px solid var(--fg); outline-offset: 1px; }
.w-bytes { display: grid; grid-template-columns: repeat(8, 1fr); gap: 3px; margin-top: 0.6rem; font-family: var(--mono); font-size: 0.8rem; }
@media (min-width: 34rem) { .w-bytes { grid-template-columns: repeat(16, 1fr); } }
.w-byte { text-align: center; padding: 0.2rem 0; border-radius: 4px; background: var(--bg); border: 1px solid var(--c, var(--border)); color: var(--c, var(--fg)); }
.w-c1 { --c: var(--uhf); }
.w-c2 { --c: var(--warn); }
.w-c3 { --c: var(--hf); }
.w-c4 { --c: var(--ok); }
.w-c5 { --c: var(--lf); }

/* ndef */
.w-ndef-parts { display: grid; gap: 0.35rem; margin-top: 0.75rem; }
.w-ndef-part { display: grid; grid-template-columns: minmax(0, 9.5rem) 1fr; gap: 0.75rem; align-items: baseline; }
.w-ndef-part .bytes { font-family: var(--mono); font-size: 0.82rem; color: var(--c); word-break: break-all; }
.w-ndef-part .what { font-size: 0.8rem; color: var(--muted); }
@media (max-width: 30rem) { .w-ndef-part { grid-template-columns: 1fr; gap: 0; } }

/* tools */
.tool-select {
  margin-left: auto;
  max-width: 11rem;
  font: inherit;
  font-size: 0.8rem;
  color: var(--fg);
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.3rem 0.4rem;
}
.tool-select:not([hidden]) + .copy-link { margin-left: 0; }
.tool-select:focus { outline: none; border-color: var(--accent); }
.tool-fit {
  margin-top: 1rem;
  padding: 0.6rem 0.9rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  font-size: 0.9rem;
}
.tool-fit.fits { border-color: color-mix(in srgb, var(--ok) 50%, transparent); color: var(--ok); }
.tool-fit.no-fit { border-color: color-mix(in srgb, var(--warn) 50%, transparent); color: var(--warn); }
.tool-fit button { font: inherit; font-family: var(--mono); font-size: 0.85rem; color: var(--fg); background: var(--card-2); border: 1px solid var(--border); border-radius: 999px; padding: 0.3rem 0.8rem; cursor: pointer; }
.tool-fit button:hover { border-color: var(--accent); color: var(--accent); }
.tool-tip {
  margin: 1rem 0;
  padding: 0.6rem 0.9rem;
  border-radius: 8px;
  background: var(--card);
  border: 1px solid var(--border);
  border-left: 3px solid var(--ok);
}
.tool-tip summary { cursor: pointer; font-family: var(--mono); font-size: 0.8rem; color: var(--ok); }
.tool-tip summary::before { content: "🧰 "; }
.tool-tip[open] summary { margin-bottom: 0.4rem; }
.tool-tip > :last-child { margin-bottom: 0.2rem; }
.widget.w-soon { border-style: dashed; color: var(--muted); text-align: center; }
@media (max-width: 30rem) { .topbar .sep, .topbar .home-learn { display: none; } }

/* stubs */
.badge.badge-stub { border-style: dashed; }
.chip.is-stub { border-style: dashed; border-left-style: solid; color: var(--muted); }
.callout-stub { border-style: dashed; border-left: 3px solid var(--muted); }
.callout-stub .callout-label { color: var(--muted); }
.callout-stub .callout-label::before { content: "🚧 "; }
.callout-stub p { color: var(--muted); }

/* figures */
.fig {
  margin: 1.5rem 0;
  padding: 0.75rem;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
}
.fig img { display: block; width: 100%; height: auto; }
.fig figcaption { margin-top: 0.5rem; font-size: 0.85rem; color: var(--muted); line-height: 1.5; }

/* map graph */
.map-graph {
  margin: 0.75rem 0 1.5rem;
  overflow: auto;
  max-height: 80vh;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg);
  -webkit-overflow-scrolling: touch;
}
.map-graph-inner { padding: 0.75rem; width: max-content; }
.map-graph svg { display: block; max-width: none; }
.map-graph .node { cursor: pointer; }
.map-graph .node:hover rect { filter: brightness(1.4); }
.map-graph .map-tick { color: var(--ok); font-weight: 700; }
.mermaid-src { display: none; }