/* ===========================================================
   BingBong — Pseudonymous Audience Intelligence
   Industrial dark theme. System fonts only. No external deps.
   =========================================================== */

:root {
  /* Carbon + petroleum palette */
  --carbon-0:   #06080b;
  --carbon-1:   #0b1015;
  --carbon-2:   #11171f;
  --carbon-3:   #182029;
  --carbon-4:   #232c37;
  --rule:       #2b3744;
  --rule-soft:  #1d2731;

  --paper:      #e8eef3;
  --paper-dim:  #b6c2cd;
  --paper-mute: #8693a1;

  --petrol:     #0e2842;
  --petrol-2:   #163a5c;
  --tel:        #6fe1ff; /* telemetry cyan */
  --tel-2:      #36b8d8;
  --signal:     #58e08a; /* signal green */
  --warn:       #ffb454; /* warning amber */
  --ult:        #8d7cff; /* restrained UV — privacy boundary */

  --bad:        #ff6b6b;
  --ok:         #58e08a;
  --muted:      #4d5966;

  --grid:       rgba(255,255,255,0.04);
  --grid-2:     rgba(111,225,255,0.08);

  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 48px;
  --space-8: 64px;
  --space-9: 96px;

  --font-sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", Menlo, Consolas, "Liberation Mono", "DejaVu Sans Mono", monospace;

  --maxw: 1180px;
  --maxw-prose: 720px;
}

@media (prefers-color-scheme: light) {
  /* BingBong is intentionally dark-first; we keep it dark even in light UA mode for brand coherence */
  :root {}
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--carbon-0);
  color: var(--paper);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.55;
  text-rendering: geometricPrecision;
  -webkit-font-smoothing: antialiased;
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
}

a {
  color: var(--tel);
  text-decoration: none;
  border-bottom: 1px solid rgba(111,225,255,0.25);
}
a:hover { border-bottom-color: var(--tel); color: #b6efff; }
a:focus-visible {
  outline: 2px solid var(--tel);
  outline-offset: 3px;
  border-radius: 2px;
}

:focus-visible {
  outline: 2px solid var(--tel);
  outline-offset: 2px;
}

h1, h2, h3, h4, h5 {
  font-family: var(--font-sans);
  letter-spacing: -0.01em;
  line-height: 1.15;
  margin: 0 0 var(--space-4);
  color: var(--paper);
  font-weight: 700;
}
h1 { font-size: clamp(2.1rem, 4.5vw, 3.4rem); letter-spacing: -0.02em; }
h2 { font-size: clamp(1.5rem, 2.6vw, 2.1rem); }
h3 { font-size: 1.2rem; }
h4 { font-size: 1.0rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--paper-dim); }

p { margin: 0 0 var(--space-4); color: var(--paper-dim); max-width: 70ch; }
p.lead { font-size: 1.15rem; color: var(--paper); }

code, kbd, samp, pre {
  font-family: var(--font-mono);
  font-size: 0.92em;
}
code { color: var(--tel); background: rgba(111,225,255,0.08); padding: 1px 6px; border-radius: 3px; }
pre { background: var(--carbon-1); border: 1px solid var(--rule); padding: var(--space-4); overflow-x: auto; border-radius: 6px; color: var(--paper); }
pre code { background: transparent; color: inherit; padding: 0; }

hr { border: 0; border-top: 1px solid var(--rule); margin: var(--space-6) 0; }

ul, ol { padding-left: 1.2em; color: var(--paper-dim); }
li { margin-bottom: 6px; }

blockquote {
  border-left: 3px solid var(--ult);
  background: rgba(141,124,255,0.06);
  margin: var(--space-4) 0;
  padding: var(--space-3) var(--space-5);
  color: var(--paper);
}

img, svg { max-width: 100%; height: auto; }

/* ---------- Layout ---------- */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--tel);
  color: var(--carbon-0);
  font-weight: 700;
  padding: 8px 14px;
  border-radius: 0 0 6px 6px;
  z-index: 999;
}
.skip-link:focus {
  left: 8px; top: 8px;
  outline: 3px solid var(--paper);
}

.wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--space-5);
}
.wrap-prose { max-width: var(--maxw-prose); margin: 0 auto; padding: 0 var(--space-5); }

.staging-banner {
  background: repeating-linear-gradient(135deg, #1a1208, #1a1208 8px, #0e0b06 8px, #0e0b06 16px);
  color: var(--warn);
  border-bottom: 1px solid #2b1e08;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  padding: 6px 0;
  text-align: center;
}
.staging-banner b { color: #ffd089; letter-spacing: 0.1em; }

/* ---------- Nav ---------- */
.site-header {
  border-bottom: 1px solid var(--rule);
  background: linear-gradient(180deg, var(--carbon-1), var(--carbon-0));
  position: sticky; top: 0; z-index: 30;
  backdrop-filter: blur(6px);
}
.nav {
  display: flex; align-items: center; gap: var(--space-5);
  padding: 14px 0;
}
.brand {
  display: inline-flex; align-items: center; gap: 10px;
  color: var(--paper); border: 0; font-weight: 700; letter-spacing: -0.01em;
  font-size: 1.05rem;
}
.brand svg { width: 28px; height: 28px; }
.brand .word { font-family: var(--font-sans); }
.brand .word b { color: var(--tel); }

.nav-links {
  display: flex; gap: var(--space-2); margin-left: auto; flex-wrap: wrap;
  list-style: none; padding: 0; margin-block: 0;
}
.nav-links a {
  display: inline-block;
  padding: 6px 10px;
  border-radius: 4px;
  color: var(--paper-dim);
  border: 1px solid transparent;
  font-size: 0.92rem;
  letter-spacing: 0.02em;
}
.nav-links a:hover { color: var(--paper); background: var(--carbon-2); border-color: var(--rule); }
.nav-links a[aria-current="page"] { color: var(--paper); border-color: var(--rule-soft); background: var(--carbon-2); }

.nav-toggle {
  display: none;
  background: var(--carbon-2);
  border: 1px solid var(--rule);
  color: var(--paper);
  padding: 6px 10px; border-radius: 4px;
  margin-left: auto;
  font: inherit; cursor: pointer;
}

@media (max-width: 880px) {
  .nav-toggle { display: inline-block; }
  .nav-links {
    display: none;
    flex-direction: column;
    width: 100%;
    background: var(--carbon-1);
    border: 1px solid var(--rule);
    border-radius: 6px;
    padding: 8px;
    margin-top: 8px;
  }
  .nav-links.open { display: flex; }
  .nav-links a { width: 100%; }
}

/* ---------- Hero ---------- */
.hero {
  padding: var(--space-9) 0 var(--space-8);
  background:
    radial-gradient(ellipse at 75% -10%, rgba(22,58,92,0.7), transparent 55%),
    radial-gradient(ellipse at 10% 0%, rgba(141,124,255,0.10), transparent 50%),
    var(--carbon-0);
  border-bottom: 1px solid var(--rule);
  position: relative; overflow: hidden;
}
.hero::before {
  content: ""; position: absolute; inset: 0;
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none; opacity: 0.7;
  mask-image: linear-gradient(180deg, transparent, #000 25%, #000 70%, transparent);
}
.hero .wrap { position: relative; z-index: 1; }
.hero .eyebrow {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--tel);
  margin-bottom: var(--space-3);
}
.hero h1 { color: var(--paper); }
.hero h1 .acc { color: var(--tel); }
.hero .lede { max-width: 56ch; font-size: 1.15rem; color: var(--paper-dim); }
.hero .actions { margin-top: var(--space-6); display: flex; gap: 12px; flex-wrap: wrap; }

/* ---------- Buttons / tags ---------- */
.btn {
  display: inline-block;
  padding: 12px 20px;
  border-radius: 4px;
  border: 1px solid var(--rule);
  font-weight: 600; letter-spacing: 0.02em;
  font-family: var(--font-sans);
  background: var(--carbon-2);
  color: var(--paper);
}
.btn:hover { background: var(--carbon-3); border-color: var(--rule); color: var(--paper); }
.btn.primary {
  background: var(--tel); color: var(--carbon-0); border-color: var(--tel);
}
.btn.primary:hover { background: #b6efff; border-color: #b6efff; color: var(--carbon-0); }
.btn.ghost { background: transparent; color: var(--paper-dim); }

.tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 3px 8px;
  border: 1px solid var(--rule);
  border-radius: 3px;
  color: var(--paper-dim);
  background: var(--carbon-1);
}
.tag.tel   { color: var(--tel);   border-color: rgba(111,225,255,0.35); }
.tag.warn  { color: var(--warn);  border-color: rgba(255,180,84,0.35); }
.tag.sig   { color: var(--signal);border-color: rgba(88,224,138,0.35); }
.tag.ult   { color: var(--ult);   border-color: rgba(141,124,255,0.4);  }
.tag.muted { color: var(--paper-mute); }

/* ---------- Sections ---------- */
section { padding: var(--space-8) 0; }
section.tight { padding: var(--space-7) 0; }
section.flush-top { padding-top: var(--space-6); }
section.divide { border-top: 1px solid var(--rule); }

.section-head { margin-bottom: var(--space-6); }
.section-head .num {
  font-family: var(--font-mono);
  color: var(--tel);
  font-size: 0.85rem;
  letter-spacing: 0.18em;
}
.section-head h2 { margin-top: 6px; }

/* ---------- Cards / grids ---------- */
.grid { display: grid; gap: var(--space-4); }
.grid.cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid.cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid.cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
@media (max-width: 880px) {
  .grid.cols-2, .grid.cols-3, .grid.cols-4 { grid-template-columns: 1fr; }
}

.card {
  background: var(--carbon-1);
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: var(--space-5);
  position: relative;
  overflow: hidden;
}
.card::before {
  content: ""; position: absolute; left: 0; top: 0; height: 100%; width: 3px;
  background: linear-gradient(180deg, var(--tel), transparent 70%);
  opacity: 0.6;
}
.card .label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--paper-mute);
  margin-bottom: 8px;
}
.card h3 { margin-bottom: 8px; }
.card p { margin-bottom: 0; color: var(--paper-dim); font-size: 0.95rem; }

/* ---------- Stat strip ---------- */
.rail {
  display: grid;
  grid-template-columns: repeat(4, minmax(0,1fr));
  gap: 0;
  border: 1px solid var(--rule);
  border-radius: 6px;
  background: var(--carbon-1);
}
.rail .cell { padding: var(--space-5); border-right: 1px solid var(--rule-soft); }
.rail .cell:last-child { border-right: 0; }
.rail .k { font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.18em; text-transform: uppercase; color: var(--paper-mute); }
.rail .v { font-size: 1.6rem; font-weight: 700; color: var(--paper); }
.rail .u { font-family: var(--font-mono); color: var(--tel); margin-left: 6px; font-size: 1.1rem; }
@media (max-width: 880px) { .rail { grid-template-columns: 1fr 1fr; } .rail .cell:nth-child(2n) { border-right: 0; } .rail .cell:nth-child(-n+2) { border-bottom: 1px solid var(--rule-soft); } }

/* ---------- Tables ---------- */
table.data {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.93rem;
  border: 1px solid var(--rule);
  background: var(--carbon-1);
  border-radius: 6px;
  overflow: hidden;
}
table.data th, table.data td {
  text-align: left;
  padding: 10px 12px;
  border-bottom: 1px solid var(--rule-soft);
  vertical-align: top;
}
table.data thead th {
  background: var(--carbon-2);
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
table.data tbody tr:hover td { background: var(--carbon-2); }
table.data td .mono { font-family: var(--font-mono); color: var(--tel); }
@media (max-width: 880px) {
  table.data {
    display: block;
    max-width: 100%;
    overflow-x: auto;
    overscroll-behavior-inline: contain;
    -webkit-overflow-scrolling: touch;
  }
  table.data th, table.data td { min-width: 9rem; }
}

/* ---------- Diagram / flow ---------- */
.flow {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr 1fr;
  gap: 0;
  border: 1px solid var(--rule);
  border-radius: 6px;
  background: var(--carbon-1);
  overflow: hidden;
}
.flow .node { padding: var(--space-5); border-right: 1px solid var(--rule-soft); position: relative; }
.flow .node:last-child { border-right: 0; }
.flow .node .label { font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.16em; color: var(--paper-mute); text-transform: uppercase; }
.flow .node .glyph { font-family: var(--font-mono); color: var(--tel); font-size: 1.4rem; margin-bottom: 6px; }
.flow .node h3 { font-size: 1.0rem; margin-bottom: 6px; }
.flow .node p { font-size: 0.9rem; }
@media (max-width: 880px) {
  .flow { grid-template-columns: 1fr; }
  .flow .node { border-right: 0; border-bottom: 1px solid var(--rule-soft); }
  .flow .node:last-child { border-bottom: 0; }
}

/* ---------- Token demo ---------- */
.tdemo {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-5);
  border: 1px solid var(--rule);
  background: var(--carbon-1);
  border-radius: 6px;
  padding: var(--space-5);
}
.tdemo .pane h4 { color: var(--paper); }
.tdemo .row {
  display: grid;
  grid-template-columns: 110px 1fr;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  padding: 8px 0;
  border-bottom: 1px dashed var(--rule-soft);
  color: var(--paper-dim);
}
.tdemo .row:last-child { border-bottom: 0; }
.tdemo .row .k { color: var(--paper-mute); }
.tdemo .row .v { color: var(--paper); }
.tdemo .row .v.token { color: var(--tel); word-break: break-all; }
@media (max-width: 880px) { .tdemo { grid-template-columns: 1fr; } }

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--rule);
  background: var(--carbon-1);
  padding: var(--space-7) 0 var(--space-6);
  color: var(--paper-dim);
  margin-top: var(--space-9);
}
.site-footer .cols {
  display: grid; grid-template-columns: 1.4fr repeat(3, 1fr); gap: var(--space-5);
}
.site-footer h4 { color: var(--paper); margin-bottom: 10px; }
.site-footer ul { list-style: none; padding: 0; margin: 0; }
.site-footer li { margin-bottom: 6px; }
.site-footer a { color: var(--paper-dim); border-color: transparent; }
.site-footer a:hover { color: var(--paper); }
.site-footer .legal {
  border-top: 1px solid var(--rule-soft);
  margin-top: var(--space-6);
  padding-top: var(--space-4);
  font-size: 0.85rem;
  color: var(--paper-mute);
  display: flex; justify-content: space-between; gap: var(--space-4); flex-wrap: wrap;
}
@media (max-width: 880px) {
  .site-footer .cols { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 540px) {
  .site-footer .cols { grid-template-columns: 1fr; }
}

/* ---------- Page hero (small) ---------- */
.page-hero {
  padding: var(--space-8) 0 var(--space-5);
  border-bottom: 1px solid var(--rule);
  background: linear-gradient(180deg, var(--carbon-1), var(--carbon-0));
}
.page-hero .eyebrow {
  font-family: var(--font-mono); font-size: 0.78rem; letter-spacing: 0.2em; text-transform: uppercase; color: var(--tel);
}
.page-hero h1 { margin-top: 6px; }
.page-hero .lede { max-width: 60ch; }

/* ---------- Prose ---------- */
.prose p, .prose li { color: var(--paper-dim); }
.prose h2 { margin-top: var(--space-6); color: var(--paper); }
.prose h3 { margin-top: var(--space-5); color: var(--paper); }
.prose h2::before {
  content: "▍"; color: var(--tel); margin-right: 8px; font-family: var(--font-mono);
}

/* ---------- Forms ---------- */
.form-row { display: grid; gap: 6px; margin-bottom: var(--space-4); }
.form-row label { font-family: var(--font-mono); font-size: 0.78rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--paper-mute); }
.form-row input, .form-row textarea, .form-row select {
  background: var(--carbon-1); color: var(--paper); border: 1px solid var(--rule);
  padding: 10px 12px; border-radius: 4px; font-family: inherit; font-size: 0.95rem;
  width: 100%;
}
.form-row input:focus, .form-row textarea:focus, .form-row select:focus {
  border-color: var(--tel); outline: 2px solid rgba(111,225,255,0.4); outline-offset: 1px;
}
.notice {
  border: 1px dashed var(--warn);
  color: var(--warn);
  background: rgba(255,180,84,0.06);
  padding: var(--space-3) var(--space-4);
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
}

/* ---------- 404 ---------- */
.notfound { padding: var(--space-9) 0; text-align: center; }
.notfound .code { font-family: var(--font-mono); font-size: 5rem; color: var(--tel); letter-spacing: 0.05em; }

/* ---------- Utility ---------- */
.row { display: flex; gap: var(--space-4); flex-wrap: wrap; align-items: center; }
.row.between { justify-content: space-between; }
.mt-0 { margin-top: 0; } .mt-4 { margin-top: var(--space-4); } .mt-6 { margin-top: var(--space-6); }
.mb-0 { margin-bottom: 0; } .mb-4 { margin-bottom: var(--space-4); } .mb-6 { margin-bottom: var(--space-6); }
.muted { color: var(--paper-mute); }
.tel { color: var(--tel); }
.warn { color: var(--warn); }
.ult { color: var(--ult); }
.signal { color: var(--signal); }
.text-center { text-align: center; }
.text-mono { font-family: var(--font-mono); }
.kbd {
  display: inline-block; padding: 1px 6px; border: 1px solid var(--rule); border-bottom-width: 2px;
  border-radius: 3px; font-family: var(--font-mono); font-size: 0.85em; background: var(--carbon-1); color: var(--paper);
}

/* ---------- Visual: arch diagram ---------- */
.arch {
  background: var(--carbon-1);
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: var(--space-5);
}
.arch svg { width: 100%; height: auto; display: block; }
.arch figcaption { font-size: 0.85rem; color: var(--paper-mute); margin-top: 8px; text-align: center; }

/* ---------- Step list ---------- */
ol.steps { list-style: none; padding: 0; counter-reset: stepc; }
ol.steps > li {
  counter-increment: stepc;
  position: relative;
  padding: var(--space-4) var(--space-5) var(--space-4) calc(var(--space-7) + 6px);
  border: 1px solid var(--rule);
  border-radius: 6px;
  margin-bottom: var(--space-3);
  background: var(--carbon-1);
}
ol.steps > li::before {
  content: counter(stepc, decimal-leading-zero);
  position: absolute; left: var(--space-4); top: var(--space-4);
  font-family: var(--font-mono); color: var(--tel);
  font-size: 1.0rem;
}

/* ---------- Trust / claims rail ---------- */
.claims {
  display: grid; gap: 12px;
  grid-template-columns: repeat(4, minmax(0,1fr));
}
.claims .claim {
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: var(--space-4);
  background: var(--carbon-1);
  font-size: 0.9rem;
}
.claims .claim .status {
  font-family: var(--font-mono); font-size: 0.7rem; letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--paper-mute); margin-bottom: 6px;
}
@media (max-width: 880px) { .claims { grid-template-columns: 1fr 1fr; } }
@media (max-width: 540px) { .claims { grid-template-columns: 1fr; } }

/* ---------- Reduced motion note ---------- */
.motion-note {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--paper-mute);
  letter-spacing: 0.16em;
  text-transform: uppercase;
}