/* Pearl PSBT — machine-shop drafting table theme.
 * Dark graphite, luminous amber/brass, subtle blueprint grid.
 * Distinct from Drop's navy/cyan family; same layout skeleton. */
:root {
  --graphite-0: #141518;
  --graphite-1: #1b1d21;
  --graphite-2: #23262c;
  --graphite-3: #2d3138;
  --ink: #ece5d3;
  --ink-dim: #b9b09a;
  --ink-faint: #979282;
  --amber: #ffb340;
  --amber-hot: #ffd27a;
  --brass: #c9973f;
  --brass-dim: #8a6a2c;
  --steel: #6e7f96;
  --ok: #7fc97f;
  --bad: #e06c5b;
  --grid: rgba(201, 151, 63, 0.055);
  --mono: ui-monospace, "SF Mono", "Cascadia Mono", Menlo, Consolas, monospace;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--graphite-0);
  background-image:
    repeating-linear-gradient(0deg, var(--grid) 0 1px, transparent 1px 28px),
    repeating-linear-gradient(90deg, var(--grid) 0 1px, transparent 1px 28px);
  color: var(--ink);
  font: 16px/1.55 -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
.mono { font-family: var(--mono); font-size: 0.86em; }
.hidden { display: none !important; }
.wrap { overflow-wrap: anywhere; word-break: break-all; }
.scroll { max-height: 320px; overflow: auto; }

/* ---------- hero ---------- */
.hero {
  position: relative;
  border-bottom: 2px solid var(--brass-dim);
  background: linear-gradient(180deg, #20232a 0%, var(--graphite-0) 100%);
  overflow: hidden;
}
.blueprint {
  position: absolute; inset: 0;
  background-image:
    repeating-linear-gradient(0deg, rgba(255,179,64,0.06) 0 1px, transparent 1px 56px),
    repeating-linear-gradient(90deg, rgba(255,179,64,0.06) 0 1px, transparent 1px 56px);
  mask-image: radial-gradient(ellipse 90% 100% at 50% 0%, #000 30%, transparent 100%);
  pointer-events: none;
}
.hero-inner { position: relative; max-width: 1080px; margin: 0 auto; padding: 40px 20px 28px; }
.kicker {
  margin: 0 0 6px; color: var(--brass); text-transform: uppercase;
  letter-spacing: 0.22em; font-size: 0.75rem; font-weight: 700;
}
h1 { margin: 0 0 10px; font-size: 2.4rem; letter-spacing: -0.01em; color: var(--amber-hot); }
.psbt-glyph { color: var(--brass); }
.sub { max-width: 72ch; color: var(--ink-dim); }
.sub strong { color: var(--ink); }

/* ---------- tabs ---------- */
.tabs { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 20px; }
.tabs button {
  appearance: none; cursor: pointer;
  background: var(--graphite-2); color: var(--ink-dim);
  border: 1px solid var(--graphite-3); border-bottom-width: 3px;
  border-radius: 6px 6px 0 0; padding: 9px 14px; font-size: 0.92rem; font-weight: 600;
}
.tabs button:hover { color: var(--amber-hot); border-color: var(--brass-dim); }
.tabs button.active {
  background: var(--graphite-1); color: var(--amber);
  border-color: var(--brass); border-bottom-color: var(--amber);
  box-shadow: 0 -2px 12px rgba(255, 179, 64, 0.12) inset;
}

/* ---------- panels ---------- */
main { max-width: 1080px; margin: 0 auto; padding: 24px 20px 40px; }
.panel {
  display: none;
  background: var(--graphite-1);
  border: 1px solid var(--graphite-3);
  border-top: 3px solid var(--brass-dim);
  border-radius: 0 0 10px 10px;
  padding: 26px 26px 30px;
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.45);
}
.panel.active { display: block; }
.panel h2 { margin: 0 0 8px; color: var(--amber); font-size: 1.35rem; }
.panel h3 { margin: 26px 0 10px; color: var(--brass); font-size: 1.02rem; }
.lede { color: var(--ink-dim); max-width: 78ch; }
.lede code, .hint code { color: var(--amber-hot); }
.hint { color: var(--ink-faint); font-size: 0.85rem; }
.warn {
  border: 1px solid var(--bad); border-left-width: 5px; border-radius: 6px;
  background: rgba(224, 108, 91, 0.08); padding: 10px 14px; margin: 14px 0;
  color: var(--ink);
}
.err { color: var(--bad); font-size: 0.9rem; align-self: center; }

/* ---------- forms ---------- */
.field { margin: 12px 0; }
.field label { display: block; margin-bottom: 6px; font-weight: 600; color: var(--ink); }
input[type="text"], input[type="password"], textarea, select {
  width: 100%; background: var(--graphite-0); color: var(--ink);
  border: 1px solid var(--graphite-3); border-radius: 6px;
  padding: 10px 12px; font-size: 0.95rem;
}
input:focus, textarea:focus, select:focus {
  outline: none; border-color: var(--brass);
  box-shadow: 0 0 0 2px rgba(201, 151, 63, 0.25);
}
textarea.tall { min-height: 150px; resize: vertical; }
textarea:not(.tall) { min-height: 84px; resize: vertical; }
.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 0 18px; }
@media (max-width: 640px) { .grid2 { grid-template-columns: 1fr; } }
.row { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin: 14px 0; }

/* ---------- buttons ---------- */
button { font: inherit; }
.primary {
  cursor: pointer; background: linear-gradient(180deg, var(--amber) 0%, var(--brass) 100%);
  color: #1a1408; border: none; border-radius: 6px; padding: 10px 20px; font-weight: 700;
  box-shadow: 0 2px 10px rgba(255, 179, 64, 0.25);
}
.primary:hover { filter: brightness(1.08); }
.primary:active { transform: translateY(1px); }
.ghost {
  cursor: pointer; background: transparent; color: var(--brass);
  border: 1px solid var(--brass-dim); border-radius: 6px; padding: 8px 14px; font-size: 0.9rem;
}
.ghost:hover { color: var(--amber-hot); border-color: var(--brass); }
.btn-link {
  display: inline-block; color: var(--brass); border: 1px solid var(--brass-dim);
  border-radius: 6px; padding: 8px 14px; font-size: 0.9rem; text-decoration: none;
}
.btn-link:hover { color: var(--amber-hot); border-color: var(--brass); }

/* ---------- outputs ---------- */
.out {
  margin-top: 18px; border: 1px dashed var(--brass-dim); border-radius: 8px;
  padding: 18px; background: rgba(201, 151, 63, 0.04);
}
.out h3 { margin-top: 18px; }
.out h3:first-child { margin-top: 0; }
pre {
  background: var(--graphite-0); border: 1px solid var(--graphite-3); border-radius: 6px;
  padding: 12px; overflow: auto; max-width: 100%; color: var(--ink);
}
code { color: var(--amber-hot); }
.kv {
  display: grid; grid-template-columns: 210px 1fr; gap: 6px 14px;
  padding: 8px 0; border-bottom: 1px solid var(--graphite-2); align-items: baseline;
}
.kv span { color: var(--ink-faint); font-size: 0.88rem; }
.kv.big code { font-size: 1.05rem; color: var(--amber); }
@media (max-width: 640px) { .kv { grid-template-columns: 1fr; } }
.stats { display: flex; flex-wrap: wrap; gap: 12px; margin: 6px 0 14px; }
.stat {
  background: var(--graphite-2); border: 1px solid var(--graphite-3);
  border-top: 2px solid var(--brass); border-radius: 6px; padding: 10px 16px; min-width: 110px;
}
.stat .num { display: block; font-size: 1.35rem; font-weight: 700; color: var(--amber); font-family: var(--mono); }
.stat .lbl { font-size: 0.78rem; color: var(--ink-faint); text-transform: uppercase; letter-spacing: 0.06em; }
.checklist { list-style: none; padding: 0; margin: 8px 0; }
.checklist li { padding: 7px 10px 7px 30px; position: relative; border-bottom: 1px solid var(--graphite-2); }
.checklist li::before { position: absolute; left: 8px; }
.checklist li.pass::before { content: "✓"; color: var(--ok); }
.checklist li.fail::before { content: "✗"; color: var(--bad); }
.checklist li.info::before { content: "·"; color: var(--brass); }
.checklist li.pass { color: var(--ink); }
.checklist li.fail { color: var(--bad); }
.tablewrap { overflow-x: auto; }
table.mono { width: 100%; border-collapse: collapse; font-size: 0.82rem; }
table.mono th, table.mono td {
  text-align: left; padding: 8px 10px; border-bottom: 1px solid var(--graphite-2);
  vertical-align: top;
}
table.mono th { color: var(--brass); font-weight: 700; text-transform: uppercase; font-size: 0.72rem; letter-spacing: 0.08em; }
.card {
  border: 1px solid var(--graphite-3); border-left: 4px solid var(--brass);
  border-radius: 6px; padding: 12px 16px; margin: 12px 0; background: var(--graphite-2);
}
.card h4 { margin: 0 0 8px; color: var(--amber); font-size: 0.98rem; }
.notes { color: var(--ink-dim); }
.notes li { margin-bottom: 10px; }
.notes strong { color: var(--ink); }

/* ---------- limits + footer ---------- */
.limits {
  max-width: 1080px; margin: 0 auto 30px; padding: 0 20px;
}
.limits > div {
  border: 1px solid var(--brass-dim); border-radius: 8px; padding: 16px 20px;
  background: rgba(201, 151, 63, 0.05);
}
.limits strong { color: var(--amber); }
.limits ul { margin: 8px 0 0; padding-left: 20px; color: var(--ink-dim); }
.limits li { margin-bottom: 6px; }
footer {
  border-top: 1px solid var(--graphite-3); padding: 22px 20px 40px;
  text-align: center; color: var(--ink-faint); font-size: 0.9rem;
}
footer a { color: var(--brass); }
footer .donate code { color: var(--amber-hot); word-break: break-all; }
footer .hint { margin-top: 8px; }

/* Keyboard focus: a visible ring in this app's accent on every interactive element (fleet focus-visible pass). */
:focus-visible { outline: 2px solid var(--amber); outline-offset: 2px; }

/* Skip link: the first Tab stop on the page — parked off-screen until keyboard focus reveals it (fleet skip-link pass). */
.skip-link { position: absolute; left: 12px; top: -64px; z-index: 1000; padding: 10px 16px; border: 2px solid var(--amber); border-radius: 8px; background: #0b0e14; color: var(--amber); font-weight: 700; text-decoration: none; transition: top .15s ease; }
.skip-link:focus-visible { top: 12px; }
main:focus { outline: none; }

/* Reduced motion: when the OS asks for reduced motion, animations and transitions finish near-instantly and scrolling is not smoothed (fleet reduced-motion pass). Near-zero durations — not animation: none — so fade-ins still land on their end state and no content can be stranded invisible. */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; scroll-behavior: auto !important; }
}