/* unsigned/learn — instrument panel. Canon: ../.impeccable.md */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #0a0a0a;
  --surface: #111111;
  --surface-2: #161616;
  --surface-3: #1c1c1c;
  --border: rgba(255,255,255,0.06);
  --border-hover: rgba(255,255,255,0.14);
  --dim: rgba(255,255,255,0.42);      /* decorative / large text only */
  --mid: rgba(255,255,255,0.62);      /* AA on bg for body text */
  --bright: rgba(255,255,255,0.87);
  --white: #eaeaea;
  --green: #00e599;
  --green-dim: rgba(0,229,153,0.12);
  --green-glow: rgba(0,229,153,0.06);
  --blue: #4d9fff;
  --purple: #a78bfa;
  --orange: #f59e0b;
  --red: #ef4444;
  --mono: 'JetBrains Mono', ui-monospace, monospace;
  --sans: 'Inter', -apple-system, sans-serif;
  --rail-w: 248px;
  --ease: cubic-bezier(0.16, 1, 0.3, 1); /* ease-out-expo-ish */
}

html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}

body {
  background: var(--bg);
  color: var(--white);
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.65;
  overflow-x: hidden;
}

/* faint grid, same as landing */
body::after {
  content: '';
  position: fixed; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.02) 1px, transparent 1px);
  background-size: 60px 60px;
  pointer-events: none; z-index: 0;
}

::selection { background: var(--green-dim); color: var(--white); }

a { color: var(--green); text-decoration: none; }
a:hover { text-decoration: underline; }

:focus-visible {
  outline: 2px solid var(--green);
  outline-offset: 2px;
  border-radius: 2px;
}
/* main receives programmatic focus for a11y — never show a ring on it */
main:focus, main:focus-visible { outline: none; }

/* ---------- shell ---------- */
header.top {
  position: fixed; top: 0; left: 0; right: 0; z-index: 90;
  display: flex; justify-content: space-between; align-items: center;
  padding: 14px 28px;
  border-bottom: 1px solid var(--border);
  background: rgba(10,10,10,0.92);
}
.logo { font-family: var(--mono); font-size: 16px; color: var(--white); letter-spacing: -0.02em; }
.logo b { color: var(--green); font-weight: 500; }
.logo span { color: var(--dim); }
.top-right { display: flex; align-items: center; gap: 18px; }

.kbd-hint {
  font-family: var(--mono); font-size: 11px; color: var(--dim);
  border: 1px solid var(--border); border-radius: 4px; padding: 3px 8px;
  background: var(--surface); cursor: pointer;
}
.kbd-hint:hover { color: var(--mid); border-color: var(--border-hover); }
kbd {
  font-family: var(--mono); font-size: 10px; color: var(--mid);
  border: 1px solid var(--border-hover); border-bottom-width: 2px;
  border-radius: 3px; padding: 1px 5px; background: var(--surface-2);
}

.gate-chip {
  display: inline-flex; align-items: center; gap: 7px;
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.06em;
  padding: 4px 10px; border-radius: 4px; border: 1px solid var(--border);
}
.gate-chip .led { width: 7px; height: 7px; border-radius: 50%; }
.gate-chip.unverified { color: var(--orange); }
.gate-chip.unverified .led { background: var(--orange); }
.gate-chip.verified { color: var(--green); border-color: rgba(0,229,153,0.3); }
.gate-chip.verified .led { background: var(--green); box-shadow: 0 0 8px var(--green); }

/* ---------- rail ---------- */
nav.rail {
  position: fixed; top: 53px; bottom: 0; left: 0; width: var(--rail-w);
  border-right: 1px solid var(--border);
  padding: 20px 0 32px; overflow-y: auto; z-index: 80;
  background: var(--bg);
}
.rail-group {
  font-family: var(--mono); font-size: 10px; letter-spacing: 0.14em;
  color: var(--dim); padding: 18px 24px 6px;
}
.rail a.item {
  display: flex; align-items: baseline; gap: 10px;
  padding: 7px 24px; color: var(--mid); font-size: 13.5px;
  border-left: 2px solid transparent;
}
.rail a.item:hover { color: var(--bright); text-decoration: none; background: var(--surface); }
.rail a.item[aria-current="page"] {
  color: var(--white); border-left-color: var(--green); background: var(--green-glow);
}
.rail .hex { font-family: var(--mono); font-size: 11px; color: var(--dim); min-width: 34px; }
.rail a.item[aria-current="page"] .hex { color: var(--green); }
.rail a.item.locked { color: var(--dim); }
.rail a.item.locked::after { content: '▝▘'; font-family: var(--mono); font-size: 9px; margin-left: auto; color: var(--dim); }
.rail a.item .badge-t { margin-left: auto; }

.badge-t, .badge-demo, .badge-live {
  font-family: var(--mono); font-size: 9px; letter-spacing: 0.1em;
  padding: 2px 6px; border-radius: 3px;
}
.badge-t { color: var(--purple); border: 1px solid rgba(167,139,250,0.35); }
.badge-demo { color: var(--orange); border: 1px solid rgba(245,158,11,0.4); }
.badge-live { color: var(--green); border: 1px solid rgba(0,229,153,0.4); }

/* ---------- main ---------- */
main {
  position: relative; z-index: 1;
  margin: 53px 0 0 var(--rail-w);
  padding: clamp(28px, 5vw, 64px) clamp(24px, 6vw, 96px) 120px;
  max-width: 1040px;
}
.view-enter { animation: rise 0.5s var(--ease) both; }
@keyframes rise { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: none; } }

.crumb { font-family: var(--mono); font-size: 11px; color: var(--dim); letter-spacing: 0.08em; margin-bottom: 14px; }
.crumb .addr { color: var(--green); }
h1 { font-size: clamp(26px, 3.4vw, 38px); font-weight: 600; letter-spacing: -0.02em; line-height: 1.15; }
.lede { color: var(--mid); font-size: 16px; margin: 12px 0 0; max-width: 62ch; }
h2 { font-size: 19px; font-weight: 600; margin: 44px 0 10px; letter-spacing: -0.01em; }
h3 { font-size: 15px; font-weight: 600; margin: 26px 0 8px; }
p { color: var(--mid); max-width: 68ch; margin: 10px 0; }
p strong, li strong { color: var(--bright); font-weight: 600; }
ul, ol { color: var(--mid); margin: 10px 0 10px 22px; max-width: 66ch; }
li { margin: 5px 0; }
code {
  font-family: var(--mono); font-size: 0.88em; color: var(--bright);
  background: var(--surface-2); border: 1px solid var(--border);
  padding: 1px 5px; border-radius: 3px;
}
pre {
  font-family: var(--mono); font-size: 12.5px; line-height: 1.7;
  background: var(--surface); border: 1px solid var(--border); border-radius: 6px;
  padding: 16px 18px; overflow-x: auto; margin: 14px 0; color: var(--bright);
  position: relative;
}
pre .c { color: var(--dim); }
pre .g { color: var(--green); }
.copy-btn {
  position: absolute; top: 8px; right: 8px;
  font-family: var(--mono); font-size: 10px; color: var(--dim);
  background: var(--surface-2); border: 1px solid var(--border); border-radius: 4px;
  padding: 3px 8px; cursor: pointer;
}
.copy-btn:hover { color: var(--green); border-color: var(--border-hover); }

/* interactive panel — the centerpiece of each explainer */
.panel {
  border: 1px solid var(--border); border-radius: 8px;
  background: var(--surface); margin: 26px 0; overflow: hidden;
}
.panel-bar {
  display: flex; align-items: center; gap: 12px;
  padding: 10px 16px; border-bottom: 1px solid var(--border);
  font-family: var(--mono); font-size: 11px; color: var(--dim); letter-spacing: 0.08em;
}
.panel-bar .spacer { flex: 1; }
.panel-body { padding: 22px; }

button.btn {
  font-family: var(--mono); font-size: 12px; letter-spacing: 0.04em;
  color: var(--green); background: var(--green-dim);
  border: 1px solid rgba(0,229,153,0.35); border-radius: 5px;
  padding: 7px 16px; cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
}
button.btn:hover { background: rgba(0,229,153,0.2); }
button.btn.ghost { color: var(--mid); background: transparent; border-color: var(--border); }
button.btn.ghost:hover { color: var(--bright); border-color: var(--border-hover); }
button.btn:disabled { opacity: 0.4; cursor: not-allowed; }

/* step-through / play sequences */
.seq { display: flex; flex-direction: column; gap: 0; }
.seq-stage { display: flex; gap: 14px; align-items: flex-start; padding: 10px 0; }
.seq-node {
  font-family: var(--mono); font-size: 12px; color: var(--mid);
  border: 1px solid var(--border); border-radius: 6px; padding: 10px 14px;
  min-width: 170px; background: var(--surface-2);
  transition: border-color 0.3s, color 0.3s, background 0.3s;
}
.seq-node .t { display: block; font-size: 10px; color: var(--dim); letter-spacing: 0.1em; margin-bottom: 3px; }
.seq-node.on { border-color: rgba(0,229,153,0.5); color: var(--white); background: var(--green-glow); }
.seq-node.on .t { color: var(--green); }
.seq-node.err { border-color: rgba(239,68,68,0.5); }
.seq-node.err .t { color: var(--red); }
.seq-arrow { color: var(--dim); font-family: var(--mono); padding: 12px 2px 0; user-select: none; }
.seq-note { font-size: 12.5px; color: var(--mid); padding: 8px 2px 0; flex: 1; min-width: 180px; }
.seq-note.on { color: var(--bright); }

/* toggles */
.toggle-row { display: flex; align-items: center; gap: 12px; margin: 10px 0; }
.switch {
  position: relative; width: 38px; height: 20px; border-radius: 10px;
  background: var(--surface-3); border: 1px solid var(--border-hover); cursor: pointer;
  transition: background 0.2s; flex: none;
}
.switch::after {
  content: ''; position: absolute; top: 2px; left: 2px; width: 14px; height: 14px;
  border-radius: 50%; background: var(--mid); transition: transform 0.2s var(--ease), background 0.2s;
}
.switch[aria-checked="true"] { background: var(--green-dim); border-color: rgba(0,229,153,0.4); }
.switch[aria-checked="true"]::after { transform: translateX(18px); background: var(--green); }
.toggle-row label { font-family: var(--mono); font-size: 12.5px; color: var(--mid); cursor: pointer; }

input[type="range"] { accent-color: var(--green); width: 100%; }
input[type="text"], textarea, select {
  font-family: var(--mono); font-size: 13px; color: var(--white);
  background: var(--surface-2); border: 1px solid var(--border-hover); border-radius: 6px;
  padding: 10px 12px; width: 100%;
}
textarea { min-height: 120px; resize: vertical; line-height: 1.6; }
textarea::placeholder, input::placeholder { color: var(--dim); }

/* verdicts */
.verdict { font-family: var(--mono); font-size: 12.5px; border-radius: 6px; padding: 10px 14px; margin-top: 12px; display: none; }
.verdict.ok { display: block; color: var(--green); background: var(--green-glow); border: 1px solid rgba(0,229,153,0.3); }
.verdict.no { display: block; color: var(--red); background: rgba(239,68,68,0.06); border: 1px solid rgba(239,68,68,0.3); }

/* source-of-truth footer on explainers */
.sot {
  margin-top: 48px; padding-top: 16px; border-top: 1px solid var(--border);
  font-family: var(--mono); font-size: 11.5px; color: var(--dim); line-height: 2;
}
.sot b { color: var(--mid); font-weight: 500; letter-spacing: 0.08em; }

.pager { display: flex; justify-content: space-between; margin-top: 28px; gap: 12px; }
.pager a {
  font-family: var(--mono); font-size: 12px; color: var(--mid);
  border: 1px solid var(--border); border-radius: 6px; padding: 10px 16px; flex: 1;
}
.pager a:hover { color: var(--white); border-color: var(--border-hover); text-decoration: none; }
.pager a span { display: block; font-size: 10px; color: var(--dim); letter-spacing: 0.1em; margin-bottom: 2px; }
.pager a.next { text-align: right; }

/* ---------- gate wizard ---------- */
.bitfield { display: flex; gap: 6px; margin: 20px 0 6px; align-items: flex-end; }
.bit {
  width: 40px; height: 52px; border: 1px solid var(--border-hover); border-radius: 5px;
  display: grid; place-items: center; font-family: var(--mono); font-size: 18px;
  color: var(--dim); background: var(--surface-2);
  transition: all 0.4s var(--ease);
}
.bit.set { color: var(--bg); background: var(--green); border-color: var(--green); font-weight: 600; }
.bit.ghost { border-style: dashed; opacity: 0.45; height: 44px; width: 34px; font-size: 12px; }
.bitfield-label { font-family: var(--mono); font-size: 11px; color: var(--dim); margin-bottom: 26px; letter-spacing: 0.06em; }
.bitfield-label .g { color: var(--green); }

.gate-step { border: 1px solid var(--border); border-radius: 8px; margin: 18px 0; background: var(--surface); }
.gate-step > summary {
  list-style: none; cursor: pointer; padding: 16px 20px;
  display: flex; align-items: center; gap: 14px;
}
.gate-step > summary::-webkit-details-marker { display: none; }
.gate-step .num {
  font-family: var(--mono); font-size: 12px; color: var(--dim);
  border: 1px solid var(--border-hover); border-radius: 4px; padding: 2px 8px;
}
.gate-step.done .num { color: var(--bg); background: var(--green); border-color: var(--green); }
.gate-step .st-title { font-weight: 600; font-size: 15px; }
.gate-step .st-state { margin-left: auto; font-family: var(--mono); font-size: 11px; color: var(--dim); letter-spacing: 0.08em; }
.gate-step.done .st-state { color: var(--green); }
.gate-step .st-body { padding: 4px 20px 22px; border-top: 1px solid var(--border); }

/* ---------- dashboard ---------- */
.dash-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); gap: 1px; background: var(--border); border: 1px solid var(--border); border-radius: 8px; overflow: hidden; margin: 24px 0; }
.tile { background: var(--surface); padding: 18px 20px; }
.tile .k { font-family: var(--mono); font-size: 10px; letter-spacing: 0.12em; color: var(--dim); }
.tile .v { font-family: var(--mono); font-size: 26px; color: var(--white); margin-top: 6px; line-height: 1.2; }
.tile .v small { font-size: 13px; color: var(--mid); }
.tile .v.ok { color: var(--green); }
.tile .v.warn { color: var(--orange); }
.tile .sub { font-size: 11.5px; color: var(--dim); font-family: var(--mono); margin-top: 4px; }

/* ---------- cost ---------- */
.cost-grid { display: grid; grid-template-columns: minmax(240px, 1fr) 1.4fr; gap: 28px; align-items: start; }
.cost-controls label { display: block; font-family: var(--mono); font-size: 11.5px; color: var(--mid); margin: 16px 0 4px; letter-spacing: 0.04em; }
.cost-controls output { color: var(--green); }
.cost-bars { display: flex; flex-direction: column; gap: 14px; }
.cbar .cb-head { display: flex; justify-content: space-between; font-family: var(--mono); font-size: 12px; color: var(--mid); margin-bottom: 5px; }
.cbar .cb-head b { color: var(--white); font-weight: 500; }
.cbar .track { height: 10px; background: var(--surface-2); border: 1px solid var(--border); border-radius: 5px; overflow: hidden; }
.cbar .fill { height: 100%; background: var(--green); border-radius: 4px; transition: width 0.4s var(--ease); min-width: 2px; }
.cbar.alt .fill { background: var(--blue); }
.cbar.alt2 .fill { background: var(--purple); }
.cbar .cb-note { font-size: 11px; color: var(--dim); font-family: var(--mono); margin-top: 4px; }

/* ---------- command palette ---------- */
.palette-wrap { position: fixed; inset: 0; z-index: 200; display: none; }
.palette-wrap.open { display: block; }
.palette-wrap .scrim { position: absolute; inset: 0; background: rgba(0,0,0,0.6); }
.palette {
  position: relative; margin: 12vh auto 0; width: min(560px, calc(100vw - 32px));
  background: var(--surface); border: 1px solid var(--border-hover); border-radius: 10px;
  overflow: hidden; animation: rise 0.18s var(--ease) both;
}
.palette input {
  border: none; border-bottom: 1px solid var(--border); border-radius: 0;
  background: transparent; padding: 16px 18px; font-size: 14px;
}
.palette input:focus-visible { outline: none; }
.palette ul { list-style: none; margin: 0; max-height: 320px; overflow-y: auto; padding: 6px; }
.palette li {
  display: flex; align-items: baseline; gap: 12px; margin: 0;
  padding: 9px 12px; border-radius: 6px; cursor: pointer;
  font-size: 13.5px; color: var(--mid);
}
.palette li .hx { font-family: var(--mono); font-size: 11px; color: var(--dim); min-width: 34px; }
.palette li .k2 { margin-left: auto; font-family: var(--mono); font-size: 10px; color: var(--dim); }
.palette li[aria-selected="true"] { background: var(--green-glow); color: var(--white); }
.palette li[aria-selected="true"] .hx { color: var(--green); }
.palette .empty { padding: 22px 16px; font-family: var(--mono); font-size: 12px; color: var(--dim); }

/* help overlay */
.help-keys { display: grid; grid-template-columns: auto 1fr; gap: 8px 18px; font-size: 13px; color: var(--mid); margin-top: 14px; }

/* lock screen for gated views */
.locked-view { text-align: left; border: 1px dashed var(--border-hover); border-radius: 8px; padding: 40px; margin-top: 30px; }
.locked-view .lk { font-family: var(--mono); color: var(--orange); font-size: 12px; letter-spacing: 0.1em; }

/* footnote */
.foot-note { font-size: 12px; color: var(--dim); font-family: var(--mono); margin-top: 10px; }

/* mobile */
@media (max-width: 900px) {
  nav.rail { display: none; }
  main { margin-left: 0; }
  .cost-grid { grid-template-columns: 1fr; }
  .mobile-nav-btn { display: inline-flex; }
}
.mobile-nav-btn { display: none; }
@media (max-width: 900px) {
  nav.rail.open { display: block; width: min(300px, 84vw); box-shadow: 24px 0 60px rgba(0,0,0,0.5); }
}