/* JL.Software — Vehicle Pixel-Scale Lab
   Brand system: Space Grotesk / DM Sans / #7c3aed */

:root {
  --color-bg: #ffffff;
  --color-bg-alt: #f8fafc;
  --color-bg-surface: #f1f5f9;
  --color-text-primary: #0f172a;
  --color-text-secondary: #475569;
  --color-text-muted: #94a3b8;
  --color-accent: #7c3aed;
  --color-accent-blue: #4f46e5;
  --color-accent-light: #ede9fe;
  --color-border: #e2e8f0;
  --color-red: #dc2626;
  --color-red-light: #fef2f2;
  --color-orange: #d97706;
  --color-green: #16a34a;
  --color-green-light: #f0fdf4;
  --color-shadow: 15 23 42;
  --font-heading: "Space Grotesk", ui-sans-serif, system-ui, sans-serif;
  --font-body: "DM Sans", ui-sans-serif, system-ui, sans-serif;
  --radius: 14px;
  --ring: 0 0 0 3px rgba(124, 58, 237, 0.28);
}

html[data-theme="dark"] {
  --color-bg: #0b1020;
  --color-bg-alt: #121a2e;
  --color-bg-surface: #182238;
  --color-text-primary: #f1f5f9;
  --color-text-secondary: #b3c0d4;
  --color-text-muted: #7c8aa3;
  --color-accent: #a78bfa;
  --color-accent-blue: #818cf8;
  --color-accent-light: #241b45;
  --color-border: #26314b;
  --color-red: #f87171;
  --color-red-light: #2a1520;
  --color-green: #4ade80;
  --color-green-light: #10251c;
  --color-shadow: 0 0 0;
}

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

html { scroll-behavior: smooth; }

body {
  background:
    radial-gradient(1100px 520px at 50% -260px, rgba(124, 58, 237, 0.10), transparent 70%),
    var(--color-bg);
  color: var(--color-text-primary);
  font-family: var(--font-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  min-height: 100%;
}

a { color: var(--color-accent); }

:where(a, button, input, select, summary):focus-visible {
  outline: none;
  box-shadow: var(--ring);
  border-radius: 8px;
}

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

.skip-link {
  position: absolute; left: -9999px; top: 8px;
  background: var(--color-accent); color: #fff; padding: 10px 16px;
  border-radius: 8px; z-index: 40; font-weight: 600;
}
.skip-link:focus { left: 16px; }

.wrap { max-width: 1080px; margin: 0 auto; padding: 0 24px; }

/* ---------- masthead ---------- */
.masthead {
  display: flex; justify-content: space-between; align-items: flex-start;
  gap: 20px; flex-wrap: wrap;
  padding: 34px 0 24px; border-bottom: 1px solid var(--color-border);
}
.logo {
  font-family: var(--font-heading); font-weight: 700;
  font-size: 1.5rem; letter-spacing: -0.02em;
}
.logo .dot, footer .dot { color: var(--color-accent); }
.logo-tagline { font-size: 0.8rem; color: var(--color-text-muted); margin-top: 2px; }

.masthead-right { display: flex; align-items: flex-start; gap: 18px; flex-wrap: wrap; }
.meta { font-size: 0.76rem; text-align: right; }
.meta > div { display: flex; gap: 8px; justify-content: flex-end; margin-bottom: 3px; }
.meta dt { color: var(--color-text-muted); }
.meta dd { color: var(--color-text-primary); font-weight: 500; }

.theme-toggle {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--font-heading); font-size: 0.78rem; font-weight: 600;
  background: var(--color-bg-alt); color: var(--color-text-secondary);
  border: 1px solid var(--color-border); border-radius: 99px;
  padding: 7px 14px; cursor: pointer; transition: border-color .18s, color .18s, background .18s;
}
.theme-toggle:hover { border-color: var(--color-accent); color: var(--color-accent); }
.theme-icon {
  width: 12px; height: 12px; border-radius: 50%;
  background: var(--color-accent);
  box-shadow: inset -4px -2px 0 0 var(--color-bg-alt);
}
html[data-theme="dark"] .theme-icon { box-shadow: none; }

/* ---------- hero ---------- */
.hero { padding: 56px 0 34px; }
.eyebrow {
  font-family: var(--font-heading); font-size: 0.72rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.14em; color: var(--color-accent);
  margin-bottom: 16px;
}
h1 {
  font-family: var(--font-heading); font-weight: 700;
  font-size: clamp(2.1rem, 6vw, 3.4rem); line-height: 1.05;
  letter-spacing: -0.035em; margin-bottom: 18px;
}
.grad {
  background: linear-gradient(96deg, var(--color-accent), var(--color-accent-blue));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.lede { font-size: 1.08rem; color: var(--color-text-secondary); max-width: 660px; }

.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 26px; }

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  font-family: var(--font-heading); font-weight: 600; font-size: 0.88rem;
  padding: 12px 22px; border-radius: 99px; text-decoration: none;
  border: 1px solid transparent; cursor: pointer;
  transition: transform .16s ease, box-shadow .16s ease, background .16s, color .16s, border-color .16s;
}
.btn-sm { padding: 8px 16px; font-size: 0.8rem; }
.btn-primary {
  background: linear-gradient(96deg, var(--color-accent), var(--color-accent-blue));
  color: #fff; box-shadow: 0 8px 22px -10px rgba(124, 58, 237, 0.85);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 14px 28px -12px rgba(124, 58, 237, 0.95); }
.btn-ghost {
  background: var(--color-bg-alt); color: var(--color-text-primary);
  border-color: var(--color-border);
}
.btn-ghost:hover { border-color: var(--color-accent); color: var(--color-accent); }

/* ---------- stat cards ---------- */
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; margin: 10px 0 8px; }
.stat {
  background: var(--color-bg-alt); border: 1px solid var(--color-border);
  border-radius: var(--radius); padding: 22px 18px;
}
.stat .num {
  font-family: var(--font-heading); font-weight: 700; font-size: 1.8rem;
  letter-spacing: -0.02em; color: var(--color-accent); line-height: 1;
  font-variant-numeric: tabular-nums;
}
.stat .lbl { font-size: 0.78rem; color: var(--color-text-secondary); margin-top: 8px; }

/* ---------- sections ---------- */
.section { padding: 46px 0; border-top: 1px solid var(--color-border); margin-top: 30px; }
.section-heading {
  display: flex; justify-content: space-between; align-items: flex-end;
  gap: 18px; flex-wrap: wrap; margin-bottom: 26px;
}
.section-index {
  font-family: var(--font-heading); font-size: 0.7rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.16em;
  color: var(--color-text-muted); margin-bottom: 8px;
}
h2 {
  font-family: var(--font-heading); font-weight: 600;
  font-size: clamp(1.35rem, 3vw, 1.75rem); letter-spacing: -0.025em;
}
h3 { font-family: var(--font-heading); font-weight: 600; font-size: 1rem; }
.ledger-note, .section-note { font-size: 0.82rem; color: var(--color-text-muted); max-width: 340px; }

.card {
  background: var(--color-bg-alt); border: 1px solid var(--color-border);
  border-radius: var(--radius); padding: 24px;
}

/* ---------- segmented switch ---------- */
.seg-switch {
  display: inline-flex; gap: 4px; padding: 4px;
  background: var(--color-bg-surface); border: 1px solid var(--color-border);
  border-radius: 99px;
}
.seg-button {
  font-family: var(--font-heading); font-size: 0.78rem; font-weight: 600;
  padding: 7px 16px; border: none; border-radius: 99px; cursor: pointer;
  background: transparent; color: var(--color-text-secondary);
  transition: background .18s, color .18s;
}
.seg-button:hover { color: var(--color-accent); }
.seg-button.is-active {
  background: var(--color-bg); color: var(--color-accent);
  box-shadow: 0 1px 3px rgba(var(--color-shadow) / 0.14);
}

/* ---------- live diagram ---------- */
.diagram-frame {
  background: var(--color-bg-alt); border: 1px solid var(--color-border);
  border-radius: var(--radius); padding: 22px 22px 16px;
  overflow: hidden;
}
#scale-diagram { width: 100%; height: auto; display: block; }
.diagram-frame figcaption {
  font-size: 0.8rem; color: var(--color-text-muted);
  margin-top: 12px; padding-top: 12px; border-top: 1px solid var(--color-border);
}
.veh-body { transition: all .35s cubic-bezier(.4, 0, .2, 1); }
/* font-size is set per-element by app.js so labels stay legible at any width */
.veh-label { font-family: var(--font-heading); font-weight: 600; }
.veh-dim { font-family: var(--font-body); fill: var(--color-text-muted); }
.grid-line { stroke: var(--color-border); stroke-width: 1; }
.dim-line { stroke: var(--color-text-muted); stroke-width: 1; stroke-dasharray: 3 3; }

/* ---------- calculator ---------- */
.calculator-grid { display: grid; grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr); gap: 18px; align-items: start; }

.preset-row { display: grid; gap: 8px; margin-bottom: 20px; }
label {
  font-family: var(--font-heading); font-size: 0.76rem; font-weight: 600;
  color: var(--color-text-secondary); display: flex; gap: 6px; align-items: baseline;
}
label > span { color: var(--color-text-muted); font-weight: 500; }

input[type="number"], select {
  width: 100%; font-family: var(--font-body); font-size: 0.95rem;
  color: var(--color-text-primary); background: var(--color-bg);
  border: 1px solid var(--color-border); border-radius: 10px;
  padding: 10px 12px; font-variant-numeric: tabular-nums;
  transition: border-color .16s, box-shadow .16s;
}
input[type="number"]:hover, select:hover { border-color: var(--color-accent); }
input.is-invalid { border-color: var(--color-red); background: var(--color-red-light); }

.input-columns { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
fieldset {
  border: 1px solid var(--color-border); border-radius: 12px;
  padding: 16px; background: var(--color-bg);
}
legend {
  display: flex; align-items: center; gap: 8px; padding: 0 8px;
  font-size: 0.78rem;
}
legend .role { color: var(--color-text-muted); }
legend strong { font-family: var(--font-heading); color: var(--color-text-primary); }
.swatch { width: 10px; height: 10px; border-radius: 3px; display: inline-block; }
.swatch-ref { background: var(--color-text-secondary); }
.swatch-target { background: var(--color-accent); }
fieldset label { margin: 14px 0 6px; }
fieldset label:first-of-type { margin-top: 4px; }

.tolerance-row {
  display: flex; align-items: flex-end; gap: 14px; flex-wrap: wrap;
  margin-top: 20px; padding-top: 18px; border-top: 1px solid var(--color-border);
}
.tolerance-row label { margin-bottom: 6px; }
.tolerance-control { display: flex; align-items: center; gap: 6px; }
.tolerance-control input { width: 92px; }
.tolerance-control span { color: var(--color-text-muted); font-size: 0.85rem; }
.tolerance-row > .btn { margin-left: auto; }

.form-error {
  margin-top: 14px; color: var(--color-red); font-size: 0.85rem; font-weight: 600;
}

/* ---------- results ---------- */
.results-panel { position: sticky; top: 20px; display: grid; gap: 18px; }

.verdict {
  display: flex; align-items: center; gap: 14px;
  border-radius: 12px; padding: 14px 16px;
  border: 1px solid var(--color-border);
}
.verdict small { display: block; font-size: 0.72rem; color: var(--color-text-muted); text-transform: uppercase; letter-spacing: 0.1em; }
.verdict strong { font-family: var(--font-heading); font-size: 1.05rem; }
.verdict-mark {
  width: 34px; height: 34px; flex: none; border-radius: 50%;
  display: grid; place-items: center; font-weight: 700; color: #fff;
}
.verdict[data-state="pass"] { background: var(--color-green-light); border-color: color-mix(in srgb, var(--color-green) 32%, transparent); }
.verdict[data-state="pass"] .verdict-mark { background: var(--color-green); }
.verdict[data-state="fail"] { background: var(--color-red-light); border-color: color-mix(in srgb, var(--color-red) 32%, transparent); }
.verdict[data-state="fail"] .verdict-mark { background: var(--color-red); }

.result-primary { display: grid; gap: 2px; }
.result-primary > span { font-size: 0.76rem; color: var(--color-text-muted); text-transform: uppercase; letter-spacing: 0.1em; }
.result-primary strong {
  font-family: var(--font-heading); font-weight: 700;
  font-size: clamp(2rem, 5vw, 2.6rem); letter-spacing: -0.03em;
  color: var(--color-accent); font-variant-numeric: tabular-nums; line-height: 1.1;
}
.result-primary small { color: var(--color-text-secondary); font-size: 0.85rem; }

.result-pair { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.result-pair > div {
  background: var(--color-bg); border: 1px solid var(--color-border);
  border-radius: 10px; padding: 12px 14px;
}
.result-pair span { display: block; font-size: 0.72rem; color: var(--color-text-muted); }
.result-pair strong {
  font-family: var(--font-heading); font-size: 1.05rem;
  font-variant-numeric: tabular-nums;
}

.error-bars { display: grid; gap: 10px; }
.bar-row { display: grid; grid-template-columns: 52px 1fr; align-items: center; gap: 10px; }
.bar-label { font-size: 0.74rem; color: var(--color-text-muted); }
.bar-track {
  position: relative; height: 8px; border-radius: 99px;
  background: var(--color-bg-surface); overflow: hidden;
}
.bar-zero { position: absolute; left: 50%; top: 0; bottom: 0; width: 1px; background: var(--color-border); }
.bar-fill {
  position: absolute; top: 0; bottom: 0; border-radius: 99px;
  background: var(--color-accent); transition: left .3s ease, width .3s ease, background .3s;
}
.bar-fill[data-state="fail"] { background: var(--color-red); }
.bar-caption { font-size: 0.72rem; color: var(--color-text-muted); }

.formula-row { display: flex; align-items: center; gap: 10px; }
.formula {
  flex: 1; font-size: 0.8rem; color: var(--color-text-secondary);
  background: var(--color-bg-surface); border-radius: 10px; padding: 10px 12px;
  font-variant-numeric: tabular-nums;
}
.copy-button {
  font-family: var(--font-heading); font-size: 0.74rem; font-weight: 600;
  padding: 8px 12px; border-radius: 8px; cursor: pointer;
  border: 1px solid var(--color-border); background: var(--color-bg);
  color: var(--color-text-secondary); transition: color .16s, border-color .16s;
}
.copy-button:hover { color: var(--color-accent); border-color: var(--color-accent); }
.copy-button.is-copied { color: var(--color-green); border-color: var(--color-green); }

/* ---------- verified render ---------- */
.comparison-frame {
  background: var(--color-bg-alt); border: 1px solid var(--color-border);
  border-radius: var(--radius); padding: 18px;
}
.image-zoom {
  display: block; position: relative; width: 100%; padding: 0;
  border: none; background: none; cursor: zoom-in; border-radius: 10px; overflow: hidden;
}
.image-zoom img { width: 100%; height: auto; display: block; border-radius: 10px; }
.zoom-hint {
  position: absolute; right: 12px; bottom: 12px;
  font-family: var(--font-heading); font-size: 0.72rem; font-weight: 600;
  background: rgba(15, 23, 42, 0.78); color: #fff;
  padding: 6px 12px; border-radius: 99px; opacity: 0; transition: opacity .2s;
}
.image-zoom:hover .zoom-hint, .image-zoom:focus-visible .zoom-hint { opacity: 1; }
.comparison-frame figcaption { font-size: 0.8rem; color: var(--color-text-muted); margin-top: 14px; }

.lightbox {
  border: none; padding: 0; background: transparent;
  max-width: min(96vw, 1500px); width: 100%;
}
.lightbox::backdrop { background: rgba(2, 6, 23, 0.86); }
.lightbox img { width: 100%; height: auto; border-radius: 12px; display: block; background: #fff; }
.lightbox-close {
  position: absolute; top: 10px; right: 14px; z-index: 2;
  width: 38px; height: 38px; border-radius: 50%; cursor: pointer;
  border: 1px solid var(--color-border); background: var(--color-bg);
  color: var(--color-text-primary); font-size: 1.3rem; line-height: 1;
}

/* ---------- spec cards ---------- */
.spec-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(228px, 1fr)); gap: 16px; }
.spec-card {
  background: var(--color-bg-alt); border: 1px solid var(--color-border);
  border-radius: var(--radius); padding: 22px; display: grid; gap: 14px;
  transition: border-color .2s, transform .2s, box-shadow .2s;
}
.spec-card:hover { border-color: var(--color-accent); transform: translateY(-3px); box-shadow: 0 16px 30px -22px rgba(var(--color-shadow) / 0.9); }
.spec-card header { display: grid; gap: 3px; border: none; padding: 0; }
.spec-card .spec-name { font-family: var(--font-heading); font-weight: 700; font-size: 1.15rem; letter-spacing: -0.02em; }
.spec-card .spec-sub { font-size: 0.76rem; color: var(--color-text-muted); }
.spec-badge {
  justify-self: start; font-family: var(--font-heading); font-size: 0.68rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.1em;
  background: var(--color-accent-light); color: var(--color-accent);
  padding: 4px 10px; border-radius: 99px;
}
.spec-rows { display: grid; gap: 0; }
.spec-row {
  display: flex; justify-content: space-between; align-items: baseline; gap: 12px;
  padding: 9px 0; border-top: 1px solid var(--color-border);
}
.spec-row:first-child { border-top: none; }
.spec-row dt { font-size: 0.78rem; color: var(--color-text-secondary); }
.spec-row dd {
  font-family: var(--font-heading); font-weight: 600; font-size: 0.92rem;
  font-variant-numeric: tabular-nums; text-align: right;
}
.spec-row dd em { font-style: normal; font-weight: 400; font-size: 0.74rem; color: var(--color-text-muted); display: block; }
.spec-meter { height: 6px; border-radius: 99px; background: var(--color-bg-surface); overflow: hidden; }
.spec-meter i { display: block; height: 100%; border-radius: 99px; background: linear-gradient(90deg, var(--color-accent), var(--color-accent-blue)); transition: width .5s cubic-bezier(.4,0,.2,1); }
.spec-meter-label { font-size: 0.7rem; color: var(--color-text-muted); }

/* ---------- table ---------- */
.table-scroll { overflow-x: auto; border: 1px solid var(--color-border); border-radius: var(--radius); }
table { width: 100%; border-collapse: collapse; font-size: 0.86rem; }
th, td { padding: 12px 14px; text-align: right; white-space: nowrap; }
th:first-child, td:first-child { text-align: left; }
thead th {
  font-family: var(--font-heading); font-size: 0.72rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.05em; color: var(--color-text-muted);
  background: var(--color-bg-surface); border-bottom: 1px solid var(--color-border);
}
tbody td { border-bottom: 1px solid var(--color-border); color: var(--color-text-secondary); font-variant-numeric: tabular-nums; }
tbody tr:last-child td { border-bottom: none; }
tbody tr:hover td { background: var(--color-bg-alt); }
td.vehicle-cell { color: var(--color-text-primary); font-weight: 600; font-family: var(--font-heading); }
td.pass-value { color: var(--color-green); font-weight: 600; }
td.fail-value { color: var(--color-red); font-weight: 600; }
td.muted-value { color: var(--color-text-muted); }
tbody tr.not-rendered td { background: var(--color-bg-alt); }
.pill {
  display: inline-block; margin-left: 6px; padding: 1px 8px; border-radius: 99px;
  font-family: var(--font-heading); font-size: 0.66rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.06em;
  background: var(--color-accent-light); color: var(--color-accent);
}

.callout {
  background: var(--color-accent-light); border-left: 4px solid var(--color-accent);
  border-radius: 0 12px 12px 0; padding: 20px 24px; margin-top: 22px;
}
.callout .tag {
  font-family: var(--font-heading); font-size: 0.7rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.1em; color: var(--color-accent); margin-bottom: 6px;
}
.callout p { color: var(--color-text-primary); font-size: 0.95rem; }

footer {
  border-top: 1px solid var(--color-border); margin-top: 40px;
  padding: 28px 0 64px; font-size: 0.8rem; color: var(--color-text-muted);
}
footer p + p { margin-top: 8px; }
footer strong { font-family: var(--font-heading); color: var(--color-text-secondary); }

/* ---------- reveal ---------- */
.reveal { opacity: 0; transform: translateY(16px); transition: opacity .55s ease, transform .55s ease; }
.reveal.is-visible { opacity: 1; transform: none; }

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .calculator-grid { grid-template-columns: 1fr; }
  .results-panel { position: static; }
}
@media (max-width: 760px) {
  .stats { grid-template-columns: repeat(2, 1fr); }
  .input-columns { grid-template-columns: 1fr; }
  .masthead-right { width: 100%; justify-content: space-between; align-items: center; }
  .meta { text-align: left; }
  .meta > div { justify-content: flex-start; }
  .section { padding: 34px 0; }
  .tolerance-row > .btn { margin-left: 0; }
}
@media (max-width: 420px) {
  .result-pair { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: 0.001ms !important; animation-duration: 0.001ms !important; }
  .reveal { opacity: 1; transform: none; }
}

/* ---------- print ---------- */
@media print {
  body { background: #fff; }
  .theme-toggle, .hero-actions, .download-link, .copy-button, .skip-link, .zoom-hint, .lightbox { display: none !important; }
  .reveal { opacity: 1 !important; transform: none !important; }
  .wrap { max-width: none; padding: 0 12mm; }
  .results-panel { position: static; }
  .card, .stat, .spec-card, .diagram-frame, .comparison-frame, .table-scroll, .callout { break-inside: avoid; }
  .section { break-inside: avoid; border-top: 1px solid #e2e8f0; }
  #scale-title-section { break-after: page; }
  .comparison { break-after: page; }
  .calculator-section { break-after: page; }
  .ledger { break-before: page; }
  .calculator-grid { grid-template-columns: 1fr 1fr; }
  .spec-grid { grid-template-columns: repeat(2, 1fr); }
}