/* SFFPC.io - datasheet styling. Single scheme (light), brushed aluminum + graphite + LED cyan + signal orange. */

:root {
  color-scheme: light;

  /* seed palette */
  --alu: #E9ECEF;
  --brushed: #D5DADF;
  --graphite: #22262B;
  --cyan-text: #007C95;
  --cyan: #00C2E0;
  --orange: #C2410C;
  --white: #FFFFFF;

  /* derived tokens (all verified for AA on the surfaces they are used on) */
  --ink: #22262B;
  --muted: #4A525A;
  --cyan-ink: #00667C;
  --orange-ink: #A8380A;
  --hairline: #B4BBC3;
  --rule: #8B939B;
  --field-edge: #5C646D;
  --rail-label: #AEB6BE;
  --rail-text: #E9ECEF;
  --orange-on-dark: #FF9A66;
  --focus: #005F73;
  --focus-dark: #00C2E0;
  --pass-bg: #E3F6FA;
  --pass-ink: #00566A;
  --tight-bg: #FFF1E0;
  --tight-ink: #8A3200;

  /* type */
  --f-head: "Bahnschrift", "DIN Alternate", "Roboto Condensed", "Arial Narrow", "Avenir Next Condensed", "Helvetica Neue", Arial, sans-serif;
  --f-body: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --f-mono: ui-monospace, "SF Mono", "Cascadia Mono", Menlo, Consolas, "Liberation Mono", monospace;

  /* spacing scale */
  --s1: 4px;
  --s2: 8px;
  --s3: 12px;
  --s4: 16px;
  --s5: 24px;
  --s6: 32px;
  --s7: 48px;
  --s8: 72px;
  --s9: 104px;

  --shadow-1: 0 1px 0 rgba(255, 255, 255, .9) inset, 0 1px 2px rgba(34, 38, 43, .14), 0 10px 26px -14px rgba(34, 38, 43, .35);
  --shadow-2: 0 1px 0 rgba(255, 255, 255, .6) inset, 0 2px 4px rgba(34, 38, 43, .2), 0 18px 40px -18px rgba(34, 38, 43, .55);
}

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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--f-body);
  font-size: clamp(1rem, .96rem + .15vw, 1.0625rem);
  line-height: 1.6;
  color: var(--ink);
  background-color: var(--alu);
  background-image:
    repeating-linear-gradient(0deg, rgba(255, 255, 255, .28) 0 1px, rgba(34, 38, 43, .018) 1px 2px),
    linear-gradient(90deg, rgba(255, 255, 255, .0), rgba(255, 255, 255, .0));
  overflow-x: hidden;
}

img, svg { max-width: 100%; }
a { color: var(--cyan-ink); text-underline-offset: .18em; text-decoration-thickness: 1px; }
a:hover { text-decoration-thickness: 2px; }

:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
}
.site-head :focus-visible, .rail :focus-visible, .on-dark :focus-visible, .site-foot :focus-visible {
  outline-color: var(--focus-dark);
}

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

.skip {
  position: absolute;
  left: var(--s4);
  top: -80px;
  z-index: 100;
  padding: var(--s3) var(--s4);
  min-height: 44px;
  background: var(--graphite);
  color: var(--white);
  font-family: var(--f-head);
  letter-spacing: .06em;
  text-transform: uppercase;
  text-decoration: none;
  border: 2px solid var(--cyan);
}
.skip:focus { top: var(--s2); }

/* ---------- Header ---------- */
.site-head {
  background: var(--graphite);
  color: var(--rail-text);
  border-bottom: 3px solid var(--cyan);
  position: relative;
  z-index: 20;
}
.head-in {
  max-width: 1520px;
  margin: 0 auto;
  padding: 0 var(--s4);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s4);
  min-height: 64px;
  flex-wrap: wrap;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--s3);
  min-height: 44px;
  color: var(--white);
  text-decoration: none;
  font-family: var(--f-head);
  font-weight: 700;
  font-size: 1.45rem;
  letter-spacing: .08em;
  text-transform: uppercase;
}
.brand b { color: var(--cyan); font-weight: 700; letter-spacing: .04em; text-transform: lowercase; }
.brand svg { width: 34px; height: 34px; flex: none; }

#site-nav ul {
  list-style: none;
  margin: 0; padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 2px;
}
#site-nav a {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 0 var(--s4);
  color: #D5DADF;
  text-decoration: none;
  font-family: var(--f-head);
  font-size: .95rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  position: relative;
  transition: background-color .15s;
}
#site-nav a::after {
  content: "";
  position: absolute;
  left: var(--s4); right: var(--s4); bottom: 5px;
  height: 3px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .2s ease;
}
#site-nav a:hover { color: var(--white); background: rgba(255, 255, 255, .07); }
#site-nav a:hover::after { transform: scaleX(1); }
#site-nav a[aria-current="page"] { color: var(--white); }
#site-nav a[aria-current="page"]::after { transform: scaleX(1); }

.menu-btn {
  display: none;
  min-height: 44px;
  min-width: 44px;
  padding: 0 var(--s4);
  background: transparent;
  color: var(--white);
  border: 2px solid #8B939B;
  font: 600 .95rem var(--f-head);
  letter-spacing: .1em;
  text-transform: uppercase;
  cursor: pointer;
}
.menu-btn:hover { border-color: var(--cyan); }

/* ---------- Shell ---------- */
.shell {
  max-width: 1520px;
  margin: 0 auto;
  padding: var(--s5) var(--s4) var(--s8);
  display: grid;
  grid-template-columns: 300px minmax(0, 1fr);
  gap: var(--s6);
  align-items: start;
}
main { min-width: 0; outline: none; }

/* ---------- Spec rail ---------- */
.rail {
  position: sticky;
  top: var(--s4);
  max-height: calc(100vh - 32px);
  overflow-y: auto;
  background: var(--graphite);
  color: var(--rail-text);
  border: 1px solid #0f1215;
  box-shadow: var(--shadow-2);
  background-image:
    repeating-linear-gradient(0deg, rgba(255, 255, 255, .035) 0 1px, rgba(0, 0, 0, 0) 1px 3px);
}
.rail-toggle {
  display: none;
  width: 100%;
  min-height: 48px;
  padding: var(--s2) var(--s4);
  align-items: center;
  justify-content: space-between;
  gap: var(--s3);
  background: transparent;
  color: var(--white);
  border: 0;
  font: 600 .95rem var(--f-head);
  letter-spacing: .1em;
  text-transform: uppercase;
  cursor: pointer;
  text-align: left;
}
.rail-toggle .rail-sum { color: var(--cyan); font-family: var(--f-mono); font-size: .85rem; letter-spacing: 0; text-transform: none; }
.rail-body { padding: var(--s4); }
.rail-title {
  margin: 0 0 var(--s3);
  display: flex;
  align-items: center;
  gap: var(--s2);
  font: 700 .8rem var(--f-head);
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--rail-label);
}
.led-dot {
  width: 9px; height: 9px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 8px 2px rgba(0, 194, 224, .65);
  display: inline-block;
}
.rail .iso { --iso-h: 150px; margin: 0 0 var(--s3); background: rgba(255, 255, 255, .04); border: 1px solid #3a4148; }
.rail .iso .lbl { display: none; }
.rail-list { margin: 0; }
.rail-list .grp {
  margin: var(--s4) 0 var(--s1);
  padding-top: var(--s3);
  border-top: 1px solid #3a4148;
  font: 700 .72rem var(--f-head);
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--rail-label);
}
.rail-list .grp:first-child { border-top: 0; margin-top: 0; padding-top: 0; }
.rail-list .row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--s3);
  padding: 5px 0;
  border-bottom: 1px dotted #4a525a;
}
.rail-list dt { font-size: .82rem; color: var(--rail-label); margin: 0; }
.rail-list dd {
  margin: 0;
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  font-size: .95rem;
  color: var(--cyan);
  text-align: right;
  font-weight: 600;
}
.rail-list dd.warn { color: var(--orange-on-dark); }
.rail-list dd.flash { animation: tick .6s ease-out; }
@keyframes tick {
  0% { background: rgba(0, 194, 224, .45); color: var(--white); }
  100% { background: transparent; }
}
.rail-note { margin: var(--s3) 0 0; font-size: .78rem; line-height: 1.45; color: var(--rail-label); }
.rail-foot { margin-top: var(--s4); padding-top: var(--s3); border-top: 1px solid #3a4148; }
.btn-rail {
  width: 100%;
  min-height: 44px;
  background: transparent;
  color: var(--rail-text);
  border: 1.5px solid #8B939B;
  font: 600 .85rem var(--f-head);
  letter-spacing: .12em;
  text-transform: uppercase;
  cursor: pointer;
}
.btn-rail:hover { border-color: var(--cyan); color: var(--white); }

/* ---------- Page head / title block ---------- */
.page-head { margin: 0 0 var(--s6); }
.kicker {
  margin: 0 0 var(--s2);
  font: 700 .82rem var(--f-head);
  letter-spacing: .24em;
  text-transform: uppercase;
  color: var(--cyan-ink);
}
h1, h2, h3, h4 { font-family: var(--f-head); margin: 0; line-height: 1.05; }
h1 {
  font-size: clamp(2.3rem, 1.2rem + 4.6vw, 4.6rem);
  font-weight: 700;
  letter-spacing: .01em;
  text-transform: uppercase;
  line-height: .95;
  max-width: 16ch;
}
h1 em { font-style: normal; color: var(--cyan-ink); }
h2 {
  font-size: clamp(1.35rem, 1.1rem + 1vw, 1.9rem);
  letter-spacing: .05em;
  text-transform: uppercase;
  font-weight: 700;
}
h3 {
  font-size: 1.1rem;
  letter-spacing: .06em;
  text-transform: uppercase;
  font-weight: 700;
}
.lede { margin: var(--s4) 0 0; max-width: 62ch; font-size: clamp(1.05rem, 1rem + .35vw, 1.25rem); line-height: 1.55; color: var(--ink); }
.titleblock {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin-top: var(--s5);
  border: 1.5px solid var(--ink);
  background: var(--white);
}
.titleblock > div {
  padding: var(--s2) var(--s3);
  border-right: 1px solid var(--ink);
  min-width: 0;
}
.titleblock > div:last-child { border-right: 0; }
.titleblock dt, .tb-l {
  display: block;
  font: 700 .66rem var(--f-head);
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0;
}
.titleblock dd, .tb-v {
  margin: 2px 0 0;
  font: 600 .98rem var(--f-mono);
  color: var(--ink);
  overflow-wrap: anywhere;
}

/* ---------- Sheets / sections ---------- */
.sheet {
  position: relative;
  background: var(--white);
  border: 1px solid var(--hairline);
  box-shadow: var(--shadow-1);
  padding: clamp(var(--s4), 2.2vw, var(--s6));
  margin: 0 0 var(--s6);
}
.sheet::before, .sheet::after {
  content: "";
  position: absolute;
  width: 14px; height: 14px;
  border: 2px solid var(--ink);
  pointer-events: none;
}
.sheet::before { top: -2px; left: -2px; border-right: 0; border-bottom: 0; }
.sheet::after { bottom: -2px; right: -2px; border-left: 0; border-top: 0; }
.sheet.dark { background: var(--graphite); color: var(--rail-text); border-color: #0f1215; }
.sheet.dark::before, .sheet.dark::after { border-color: var(--cyan); }
.sheet.dark a { color: var(--cyan); }

.sec-h {
  display: flex;
  align-items: baseline;
  gap: var(--s3);
  margin: 0 0 var(--s4);
  padding-bottom: var(--s3);
  border-bottom: 2px solid var(--ink);
  flex-wrap: wrap;
}
.sheet.dark .sec-h { border-bottom-color: var(--cyan); }
.sec-n {
  font: 700 .9rem var(--f-mono);
  color: var(--cyan-ink);
  letter-spacing: .04em;
}
.sheet.dark .sec-n { color: var(--cyan); }
.sec-h .sec-aside { margin-left: auto; font: 600 .78rem var(--f-head); letter-spacing: .16em; text-transform: uppercase; color: var(--muted); }
.sheet.dark .sec-aside { color: var(--rail-label); }

.prose p { margin: 0 0 var(--s4); max-width: 68ch; }
.prose p:last-child { margin-bottom: 0; }
.prose h3 { margin: var(--s5) 0 var(--s2); }
.prose ul, .prose ol { margin: 0 0 var(--s4); padding-left: 1.25em; max-width: 66ch; }
.prose li { margin-bottom: var(--s2); }
.prose li::marker { color: var(--cyan-ink); font-weight: 700; }
.sheet.dark .prose li::marker { color: var(--cyan); }

.grid-2 { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--s5); }
.grid-3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--s5); }
.grid-tool { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 6fr); gap: var(--s5); align-items: start; }

.callout {
  margin: var(--s4) 0;
  padding: var(--s3) var(--s4);
  border-left: 5px solid var(--orange);
  background: var(--tight-bg);
  color: var(--ink);
  max-width: 68ch;
  font-size: .95rem;
}
.callout strong { font-family: var(--f-head); letter-spacing: .08em; text-transform: uppercase; color: var(--tight-ink); }
.callout.info { border-left-color: var(--cyan-text); background: var(--pass-bg); }
.callout.info strong { color: var(--pass-ink); }

/* ---------- Tables ---------- */
table.spec {
  width: 100%;
  border-collapse: collapse;
  font-size: .9rem;
  font-variant-numeric: tabular-nums;
}
table.spec caption {
  text-align: left;
  padding: 0 0 var(--s2);
  font: 700 .74rem var(--f-head);
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--muted);
}
table.spec th, table.spec td {
  padding: 7px var(--s3);
  text-align: left;
  border-bottom: 1px solid var(--hairline);
  vertical-align: middle;
}
table.spec thead th {
  background: var(--ink);
  color: var(--white);
  font: 700 .72rem var(--f-head);
  letter-spacing: .16em;
  text-transform: uppercase;
  border-bottom: 0;
  white-space: nowrap;
}
table.spec tbody th { font-weight: 600; color: var(--ink); }
table.spec tbody tr:nth-child(even) { background: #F3F5F7; }
table.spec td.num, table.spec th.num { text-align: right; font-family: var(--f-mono); }
table.spec tr.is-pick { background: var(--pass-bg) !important; outline: 2px solid var(--cyan-text); outline-offset: -2px; }
table.spec tfoot th, table.spec tfoot td { border-top: 2px solid var(--ink); border-bottom: 0; font-weight: 700; background: var(--brushed); }
table.spec td a { font-weight: 600; }
.tbl-wrap { overflow-x: auto; }

/* ---------- Forms ---------- */
fieldset { border: 0; margin: 0 0 var(--s5); padding: 0; min-width: 0; }
legend {
  padding: 0;
  margin: 0 0 var(--s3);
  font: 700 .8rem var(--f-head);
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--cyan-ink);
  width: 100%;
  border-bottom: 1px solid var(--hairline);
  padding-bottom: var(--s2);
}
.field { margin: 0 0 var(--s4); min-width: 0; }
.field > label, .lbl-t {
  display: block;
  margin: 0 0 var(--s1);
  font: 600 .78rem var(--f-head);
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--ink);
}
.inp {
  display: flex;
  align-items: stretch;
  border: 1.5px solid var(--field-edge);
  background: var(--white);
  min-height: 46px;
}
.inp:focus-within { outline: 3px solid var(--focus); outline-offset: 2px; }
.inp input {
  flex: 1;
  min-width: 0;
  border: 0;
  background: transparent;
  padding: 0 var(--s3);
  font: 600 1.05rem var(--f-mono);
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}
.inp input:focus { outline: none; }
.inp input::placeholder { color: var(--field-edge); opacity: 1; }
.inp .unit {
  display: flex;
  align-items: center;
  padding: 0 var(--s3);
  background: var(--brushed);
  color: var(--ink);
  border-left: 1.5px solid var(--field-edge);
  font: 700 .8rem var(--f-head);
  letter-spacing: .12em;
  text-transform: uppercase;
  min-width: 48px;
  justify-content: center;
}
.inp.is-bad { border-color: var(--orange-ink); border-width: 2px; background: #FFF8F2; }
.field select, .field textarea, .plain-input {
  width: 100%;
  min-height: 46px;
  border: 1.5px solid var(--field-edge);
  background: var(--white);
  color: var(--ink);
  font: 500 1rem var(--f-body);
  padding: 0 var(--s3);
  border-radius: 0;
}
.field textarea { padding: var(--s3); min-height: 150px; resize: vertical; line-height: 1.5; }
.field select { font-family: var(--f-mono); font-weight: 600; }
.hint { margin: var(--s1) 0 0; font-size: .8rem; color: var(--muted); }
.err {
  margin: var(--s1) 0 0;
  font-size: .85rem;
  font-weight: 600;
  color: var(--orange-ink);
  display: flex;
  gap: 6px;
  align-items: flex-start;
}
.err::before { content: "\2715"; font-weight: 700; }
.err[hidden] { display: none; }
.pair { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--s3); }
.triple { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--s3); }

.seg {
  display: inline-flex;
  border: 1.5px solid var(--ink);
  background: var(--white);
}
.seg label {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 64px;
  min-height: 44px;
  padding: 0 var(--s4);
  cursor: pointer;
  font: 700 .9rem var(--f-head);
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--ink);
  margin: 0;
}
.seg label + label { border-left: 1.5px solid var(--ink); }
.seg input { position: absolute; opacity: 0; inset: 0; margin: 0; cursor: pointer; }
.seg label:has(input:checked) { background: var(--ink); color: var(--white); }
.seg label:has(input:focus-visible) { outline: 3px solid var(--focus); outline-offset: 2px; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--s2);
  min-height: 46px;
  padding: 0 var(--s5);
  border: 2px solid var(--ink);
  background: var(--ink);
  color: var(--white);
  font: 700 .9rem var(--f-head);
  letter-spacing: .14em;
  text-transform: uppercase;
  text-decoration: none;
  cursor: pointer;
  box-shadow: 3px 3px 0 var(--cyan);
  transition: transform .12s, box-shadow .12s, background-color .12s;
}
.btn:hover { transform: translate(-1px, -1px); box-shadow: 5px 5px 0 var(--cyan); }
.btn:active { transform: translate(2px, 2px); box-shadow: 1px 1px 0 var(--cyan); }
.btn.led { background: var(--cyan); color: var(--ink); border-color: var(--ink); box-shadow: 3px 3px 0 var(--ink); }
.btn.led:hover { box-shadow: 5px 5px 0 var(--ink); }
.btn.ghost { background: var(--white); color: var(--ink); box-shadow: none; }
.btn.ghost:hover { background: var(--brushed); transform: none; box-shadow: none; }
.btn.sm { min-height: 44px; padding: 0 var(--s4); font-size: .8rem; }
.btn[aria-pressed="true"] { background: var(--cyan); color: var(--ink); }
.btn-row { display: flex; flex-wrap: wrap; gap: var(--s3); align-items: center; }
.sheet.dark .btn.ghost { background: transparent; color: var(--white); border-color: #8B939B; }
.sheet.dark .btn.ghost:hover { background: rgba(255, 255, 255, .08); border-color: var(--cyan); }

.range-row { display: grid; grid-template-columns: auto minmax(0, 1fr) auto; gap: var(--s3); align-items: center; margin-bottom: var(--s2); }
.range-row label { font: 600 .78rem var(--f-head); letter-spacing: .14em; text-transform: uppercase; }
.range-row output { font: 700 .95rem var(--f-mono); min-width: 5.5ch; text-align: right; }
input[type="range"] { width: 100%; height: 44px; accent-color: var(--cyan-text); background: transparent; margin: 0; }
input[type="range"]:focus-visible { outline: 3px solid var(--focus); outline-offset: 0; }
.sheet.dark input[type="range"]:focus-visible { outline-color: var(--focus-dark); }

/* ---------- Tags / status ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  border: 2px solid currentColor;
  font: 700 .82rem var(--f-head);
  letter-spacing: .12em;
  text-transform: uppercase;
  white-space: nowrap;
  line-height: 1.2;
}
.tag::before { font-weight: 700; }
.tag.pass { color: var(--pass-ink); background: var(--pass-bg); }
.tag.pass::before { content: "\2713"; }
.tag.tight { color: var(--tight-ink); background: var(--tight-bg); }
.tag.tight::before { content: "!"; }
.tag.fail { color: var(--white); background: var(--orange); border-color: var(--orange); }
.tag.fail::before { content: "\2715"; }
.tag.idle { color: var(--muted); background: #F1F3F5; border-color: var(--rule); }
.tag.idle::before { content: "\2013"; }

/* ---------- LED readouts ---------- */
.readouts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1px;
  background: #3a4148;
  border: 1px solid #0f1215;
}
.ro {
  background: var(--graphite);
  padding: var(--s3) var(--s4);
  min-width: 0;
}
.ro .k { display: block; font: 700 .68rem var(--f-head); letter-spacing: .2em; text-transform: uppercase; color: var(--rail-label); }
.ro .v {
  display: block;
  margin-top: 2px;
  font: 700 clamp(1.6rem, 1.2rem + 1.6vw, 2.5rem) var(--f-head);
  letter-spacing: .02em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
  text-shadow: 0 0 14px rgba(0, 194, 224, .35);
  overflow-wrap: anywhere;
  line-height: 1.1;
}
.ro .v small { font-size: .45em; letter-spacing: .12em; color: var(--rail-text); margin-left: 4px; text-transform: uppercase; }
.ro .v.warn { color: var(--orange-on-dark); text-shadow: none; }
.ro .s { display: block; font-size: .78rem; color: var(--rail-label); margin-top: 2px; }
.ro.big { grid-column: 1 / -1; }

/* ---------- Isometric case model (CSS faces, affine-projected by script.js) ---------- */
.iso {
  position: relative;
  width: 100%;
  height: var(--iso-h, 320px);
  overflow: hidden;
  --grid: 60px;
  user-select: none;
  -webkit-user-select: none;
}
.iso[data-drag] { cursor: grab; touch-action: pan-y; }
.iso[data-drag].dragging { cursor: grabbing; }
.iso-stage { position: absolute; left: 50%; top: 50%; width: 0; height: 0; }
.iso-cube { position: absolute; left: 0; top: 0; }
.iso-floor, .iso-shadow, .f { position: absolute; left: 0; top: 0; transform-origin: 0 0; }
.iso-floor {
  width: 640px; height: 640px;
  background-image:
    linear-gradient(rgba(0, 124, 149, .55) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 124, 149, .55) 1px, transparent 1px);
  background-size: var(--grid) var(--grid);
  background-position: 50% 50%;
  -webkit-mask-image: radial-gradient(circle at 50% 50%, #000 18%, transparent 62%);
  mask-image: radial-gradient(circle at 50% 50%, #000 18%, transparent 62%);
}
.rail .iso-floor {
  background-image:
    linear-gradient(rgba(0, 194, 224, .45) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 194, 224, .45) 1px, transparent 1px);
}
.iso-shadow { background: rgba(34, 38, 43, .38); filter: blur(9px); }
.f {
  overflow: hidden;
  border: 1px solid rgba(34, 38, 43, .7);
  box-sizing: border-box;
  background-image: repeating-linear-gradient(0deg, rgba(255, 255, 255, .16) 0 1px, rgba(0, 0, 0, .04) 1px 2px);
}
.f-back, .f-left, .f-bottom { display: none; }
.f-front  { background-color: #D5DADF; background-image: linear-gradient(180deg, rgba(255, 255, 255, .45), rgba(0, 0, 0, .08)), repeating-linear-gradient(0deg, rgba(255, 255, 255, .16) 0 1px, rgba(0, 0, 0, .04) 1px 2px); }
.f-right  { background-color: #A9B1B9; }
.f-top    { background-color: #EEF1F3; }
.f-left   { background-color: #8E969E; }
.f-back   { background-color: #8E969E; }
.f-bottom { background-color: #7F8790; }
.f-front::before {
  content: "";
  position: absolute;
  left: 10%; right: 10%; top: 14%; bottom: 26%;
  background: radial-gradient(circle at 50% 50%, rgba(34, 38, 43, .75) 0 1.3px, transparent 1.7px) 0 0 / 6px 6px;
  opacity: .6;
}
.f-front::after {
  content: "";
  position: absolute;
  left: 10%; right: 10%; bottom: 10%;
  height: 3px;
  background: var(--cyan);
  box-shadow: 0 0 9px 2px rgba(0, 194, 224, .85);
}
.f-right::before {
  content: "";
  position: absolute;
  inset: 16% 12%;
  background: radial-gradient(circle at 50% 50%, rgba(34, 38, 43, .6) 0 1.6px, transparent 2px) 0 0 / 9px 9px;
  opacity: .55;
}
.f-top::before {
  content: "";
  position: absolute;
  inset: 14% 10%;
  background: repeating-linear-gradient(90deg, rgba(34, 38, 43, .55) 0 2px, transparent 2px 8px);
}
.lbl {
  position: absolute;
  z-index: 2;
  padding: 3px 5px;
  background: var(--white);
  color: var(--ink);
  border: 1px solid var(--ink);
  font: 700 10px/1 var(--f-mono);
  white-space: nowrap;
  letter-spacing: .02em;
}
.lbl-w { left: 50%; top: 6px; transform: translateX(-50%); }
.lbl-d { left: 50%; top: 6px; transform: translateX(-50%); }
.lbl-h { left: 4px; top: 50%; transform: translateY(-50%); }

.iso.is-glass .f-back, .iso.is-glass .f-left, .iso.is-glass .f-bottom { display: block; }
.iso.is-glass .f { background-image: none !important; background-color: rgba(0, 194, 224, .1) !important; border-color: var(--ink); }
.iso.is-glass .f::before, .iso.is-glass .f::after { display: none; }

.iso-frame {
  position: relative;
  background: var(--white);
  border: 1.5px solid var(--ink);
  background-image:
    linear-gradient(rgba(34, 38, 43, .06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(34, 38, 43, .06) 1px, transparent 1px);
  background-size: 20px 20px;
}
.iso-frame::before, .iso-frame::after {
  position: absolute;
  font: 700 .66rem var(--f-head);
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--muted);
  z-index: 3;
}
.iso-frame::before { content: attr(data-tl); top: 8px; left: 10px; }
.iso-frame::after { content: attr(data-br); bottom: 8px; right: 10px; }
.iso-ctl {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s3);
  align-items: center;
  padding: var(--s3);
  border: 1.5px solid var(--ink);
  border-top: 0;
  background: var(--brushed);
}
.iso-ctl .range-row { flex: 1 1 220px; margin: 0; }

/* ---------- Gauges ---------- */
.strip {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  grid-template-areas: "nm out" "gauge gauge";
  gap: var(--s2) var(--s4);
  align-items: center;
  padding: var(--s4) 0;
  border-bottom: 1px solid var(--hairline);
}
.strip:first-of-type { border-top: 2px solid var(--ink); }
.strip > .nm { grid-area: nm; } .strip > .out { grid-area: out; } .strip > .gauge, .strip > p { grid-area: gauge; }
.strip .nm { font: 700 1rem var(--f-head); letter-spacing: .1em; text-transform: uppercase; }
.strip .nm small { display: block; font: 500 .78rem var(--f-body); letter-spacing: 0; text-transform: none; color: var(--muted); margin-top: 2px; }
.strip .out { text-align: right; min-width: 128px; }
.strip .out .mg { display: block; margin-top: 4px; font: 700 1.05rem var(--f-mono); font-variant-numeric: tabular-nums; }
.gauge .g-track {
  position: relative;
  height: 28px;
  background: var(--alu);
  border: 1.5px solid var(--ink);
}
.g-fill { position: absolute; left: 0; top: 0; bottom: 0; background: var(--cyan); border-right: 2px solid var(--ink); transition: width .4s cubic-bezier(.2, .8, .2, 1); }
.g-buf {
  position: absolute; top: 0; bottom: 0;
  background: repeating-linear-gradient(90deg, rgba(34, 38, 43, .55) 0 2px, transparent 2px 5px);
  transition: all .4s cubic-bezier(.2, .8, .2, 1);
}
.g-over {
  position: absolute; top: 0; bottom: 0;
  background: repeating-linear-gradient(45deg, var(--orange) 0 5px, var(--white) 5px 10px);
  border-left: 0;
  transition: all .4s cubic-bezier(.2, .8, .2, 1);
}
.g-limit { position: absolute; top: -8px; bottom: -8px; width: 0; border-left: 3px solid var(--ink); transition: left .4s cubic-bezier(.2, .8, .2, 1); }
.g-limit span {
  position: absolute; top: -17px; left: 50%; transform: translateX(-50%);
  font: 700 .62rem var(--f-head); letter-spacing: .16em; text-transform: uppercase; white-space: nowrap; color: var(--ink);
}
.g-scale { display: flex; justify-content: space-between; margin-top: 6px; font: 500 .72rem var(--f-mono); color: var(--muted); }
.gauge { padding-top: 14px; }

.verdict {
  display: flex;
  gap: var(--s4);
  align-items: center;
  flex-wrap: wrap;
  padding: var(--s4);
  margin-bottom: var(--s5);
  border: 2px solid var(--ink);
  background: var(--brushed);
}
.verdict .vt { font: 700 clamp(1.2rem, 1rem + 1vw, 1.7rem) var(--f-head); letter-spacing: .06em; text-transform: uppercase; }
.verdict p { margin: 0; flex: 1 1 260px; color: var(--ink); }

/* ---------- Power ---------- */
.stack {
  display: flex;
  height: 34px;
  border: 1.5px solid var(--ink);
  background: var(--alu);
  overflow: hidden;
}
.stack span { display: block; height: 100%; border-right: 1.5px solid var(--ink); min-width: 0; transition: width .4s cubic-bezier(.2, .8, .2, 1); }
.stack span:last-child { border-right: 0; }
.seg-a { background: var(--cyan); }
.seg-b { background: repeating-linear-gradient(45deg, var(--cyan) 0 4px, #8EE7F4 4px 8px); }
.seg-c { background: var(--graphite); }
.seg-d { background: repeating-linear-gradient(90deg, var(--graphite) 0 3px, #5C646D 3px 6px); }
.seg-e { background: var(--brushed); }
.seg-f { background: repeating-linear-gradient(45deg, var(--orange) 0 4px, #F2A27E 4px 8px); }
.seg-g { background: repeating-linear-gradient(0deg, #8B939B 0 3px, #D5DADF 3px 6px); }
.swatch { display: inline-block; width: 16px; height: 16px; border: 1.5px solid var(--ink); vertical-align: -3px; margin-right: 6px; }
.pw-input { width: 100%; max-width: 140px; }
.pw-name { font-weight: 600; }
.pw-name-input { width: 100%; min-height: 44px; border: 1.5px solid var(--field-edge); padding: 0 var(--s2); font: 600 .9rem var(--f-body); background: var(--white); color: var(--ink); }
.rm-btn {
  min-width: 44px; min-height: 44px;
  background: var(--white); color: var(--ink);
  border: 1.5px solid var(--field-edge);
  font: 700 1.1rem var(--f-head);
  cursor: pointer;
}
.rm-btn:hover { background: var(--ink); color: var(--white); }
.pw-in { display: flex; border: 1.5px solid var(--field-edge); background: var(--white); min-height: 44px; max-width: 150px; }
.pw-in:focus-within { outline: 3px solid var(--focus); outline-offset: 2px; }
.pw-in input { width: 100%; min-width: 0; border: 0; background: transparent; padding: 0 var(--s2); font: 600 1rem var(--f-mono); text-align: right; color: var(--ink); }
.pw-in input:focus { outline: none; }
.pw-in span { display: flex; align-items: center; padding: 0 8px; background: var(--brushed); border-left: 1.5px solid var(--field-edge); font: 700 .75rem var(--f-head); letter-spacing: .1em; }
.pw-in.is-bad { border-color: var(--orange-ink); border-width: 2px; background: #FFF8F2; }
tr.row-err td { padding-top: 0; border-bottom: 1px solid var(--hairline); }

/* ---------- Build order ---------- */
.progress {
  position: relative;
  height: 22px;
  border: 1.5px solid var(--ink);
  background: var(--white);
  overflow: hidden;
}
.progress i { position: absolute; left: 0; top: 0; bottom: 0; width: 0; background: var(--cyan); border-right: 2px solid var(--ink); transition: width .4s cubic-bezier(.2, .8, .2, 1); }
.progress-meta { display: flex; justify-content: space-between; gap: var(--s3); margin: 0 0 var(--s2); font: 700 .78rem var(--f-head); letter-spacing: .16em; text-transform: uppercase; flex-wrap: wrap; }
.phase { margin: 0 0 var(--s6); }
.phase-h { display: flex; align-items: center; gap: var(--s3); flex-wrap: wrap; margin-bottom: var(--s3); }
.phase-h .pn {
  display: grid; place-items: center;
  width: 44px; height: 44px;
  background: var(--ink); color: var(--cyan);
  font: 700 1.3rem var(--f-head);
}
.phase-h h2 { flex: 1 1 200px; }
.phase-h .cnt { font: 700 .9rem var(--f-mono); color: var(--muted); }
.steps { list-style: none; margin: 0; padding: 0; border-top: 2px solid var(--ink); }
.step { border-bottom: 1px solid var(--hairline); padding: var(--s2) 0; }
.step.is-done .step-title { text-decoration: line-through; text-decoration-thickness: 2px; color: var(--muted); }
.step[hidden] { display: none; }
.step-check {
  display: grid;
  grid-template-columns: 32px minmax(0, 1fr);
  gap: var(--s3);
  align-items: start;
  min-height: 44px;
  padding: 6px 0;
  cursor: pointer;
}
.step-check input {
  appearance: none; -webkit-appearance: none;
  width: 30px; height: 30px; margin: 0;
  border: 2px solid var(--ink);
  background: var(--white);
  display: grid; place-items: center;
  cursor: pointer;
}
.step-check input::before {
  content: "";
  width: 14px; height: 8px;
  border-left: 4px solid var(--ink);
  border-bottom: 4px solid var(--ink);
  transform: rotate(-45deg) translate(1px, -2px);
  opacity: 0;
}
.step-check input:checked { background: var(--cyan); }
.step-check input:checked::before { opacity: 1; }
.step-check input:focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; }
.step-title { font-weight: 600; line-height: 1.35; padding-top: 3px; }
.step-title .sid { font: 700 .78rem var(--f-mono); color: var(--cyan-ink); margin-right: 8px; letter-spacing: .04em; }
.step details { margin-left: 44px; }
.step summary {
  display: inline-flex; align-items: center; min-height: 40px;
  cursor: pointer;
  font: 600 .78rem var(--f-head); letter-spacing: .14em; text-transform: uppercase;
  color: var(--cyan-ink);
}
.step details p { margin: 0 0 var(--s3); max-width: 62ch; font-size: .95rem; color: var(--ink); }

/* ---------- Contact ---------- */
.slip {
  background: var(--white);
  border: 1.5px solid var(--ink);
  padding: var(--s4);
  font: 500 .9rem/1.55 var(--f-mono);
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  min-height: 160px;
  background-image: repeating-linear-gradient(0deg, transparent 0 26px, rgba(0, 124, 149, .12) 26px 27px);
}
.copy-status { min-height: 1.5em; font-size: .9rem; font-weight: 600; color: var(--pass-ink); margin: var(--s2) 0 0; }

/* ---------- Cards / index ---------- */
.hero {
  display: grid;
  grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
  gap: var(--s6);
  align-items: stretch;
  margin-bottom: var(--s6);
}
.hero-copy { display: flex; flex-direction: column; justify-content: center; padding: var(--s4) 0; }
.hero-copy .btn-row { margin-top: var(--s5); }
.hero .iso { --iso-h: 330px; }
.sheet-idx { list-style: none; margin: 0; padding: 0; counter-reset: sh; }
.sheet-idx li { border-bottom: 1px solid var(--hairline); }
.sheet-idx li:first-child { border-top: 2px solid var(--ink); }
.sheet-idx a {
  display: grid;
  grid-template-columns: 64px minmax(0, 1fr) auto;
  gap: var(--s4);
  align-items: center;
  min-height: 72px;
  padding: var(--s3) var(--s2);
  color: var(--ink);
  text-decoration: none;
  transition: background-color .15s, padding-left .15s;
}
.sheet-idx a:hover { background: var(--pass-bg); padding-left: var(--s4); }
.sheet-idx .sn { font: 700 1.8rem var(--f-head); color: var(--cyan-ink); }
.sheet-idx .st { font: 700 1.15rem var(--f-head); letter-spacing: .08em; text-transform: uppercase; display: block; }
.sheet-idx .sd { display: block; font-size: .92rem; color: var(--muted); margin-top: 2px; }
.sheet-idx .go { font: 700 .8rem var(--f-head); letter-spacing: .16em; text-transform: uppercase; color: var(--cyan-ink); }
.facts { list-style: none; padding: 0; margin: var(--s5) 0 0; display: grid; gap: 0; border-top: 1px solid var(--rule); }
.facts li { display: flex; justify-content: space-between; gap: var(--s4); padding: 7px 0; border-bottom: 1px solid var(--hairline); font-size: .92rem; }
.facts li span:first-child { font: 700 .72rem var(--f-head); letter-spacing: .16em; text-transform: uppercase; color: var(--muted); padding-top: 3px; }
.facts li span:last-child { font-family: var(--f-mono); font-weight: 600; text-align: right; }
.draw { display: block; width: 100%; height: auto; }
.draw text { font-family: var(--f-mono); }
.fig-cap { margin: var(--s2) 0 0; font-size: .82rem; color: var(--muted); }

.num-list { counter-reset: n; list-style: none; padding: 0; margin: 0; display: grid; gap: var(--s4); }
.num-list li { counter-increment: n; position: relative; padding-left: 56px; }
.num-list li::before {
  content: counter(n, decimal-leading-zero);
  position: absolute; left: 0; top: -2px;
  font: 700 1.7rem var(--f-head);
  color: var(--cyan-ink);
}
.num-list h3 { margin-bottom: var(--s1); }
.num-list p { margin: 0; max-width: 60ch; }

/* ---------- Footer ---------- */
.site-foot {
  background: var(--graphite);
  color: var(--rail-text);
  border-top: 3px solid var(--cyan);
  padding: var(--s6) var(--s4) var(--s5);
}
.foot-in { max-width: 1520px; margin: 0 auto; display: grid; grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr) minmax(0, 1fr); gap: var(--s6); }
.site-foot .fb { font: 700 1.4rem var(--f-head); letter-spacing: .08em; text-transform: uppercase; color: var(--white); margin: 0 0 var(--s2); }
.site-foot .fb b { color: var(--cyan); text-transform: lowercase; }
.site-foot p { margin: 0 0 var(--s2); font-size: .92rem; color: #C4CBD2; max-width: 52ch; }
.site-foot h2 { font-size: .8rem; letter-spacing: .22em; color: var(--rail-label); margin-bottom: var(--s2); }
.site-foot ul { list-style: none; margin: 0; padding: 0; }
.site-foot li a, .site-foot p a { display: inline-flex; align-items: center; min-height: 40px; color: var(--cyan); }
.site-foot a:hover { color: var(--white); }
.foot-legal { grid-column: 1 / -1; border-top: 1px solid #3a4148; padding-top: var(--s4); font-size: .85rem; color: #C4CBD2; }

/* ---------- Responsive ---------- */
@media (max-width: 1180px) {
  .shell { grid-template-columns: 260px minmax(0, 1fr); gap: var(--s5); }
  .grid-tool { grid-template-columns: minmax(0, 1fr); }
  .hero { grid-template-columns: minmax(0, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 960px) {
  .shell { grid-template-columns: minmax(0, 1fr); padding-top: var(--s4); }
  .rail { position: relative; top: 0; max-height: none; overflow: visible; }
  .rail-toggle { display: flex; }
  .rail-body { display: none; padding-top: 0; }
  .rail.open .rail-body { display: block; }
  .rail .iso { --iso-h: 170px; }
  .foot-in { grid-template-columns: 1fr 1fr; }
  .foot-in > :first-child { grid-column: 1 / -1; }
}
@media (max-width: 760px) {
  .menu-btn { display: inline-flex; align-items: center; }
  .js #site-nav { display: none; width: 100%; padding-bottom: var(--s3); }
  .js #site-nav.open { display: block; }
  #site-nav { width: 100%; }
  #site-nav ul { flex-direction: column; }
  #site-nav a { border-top: 1px solid #3a4148; }
  #site-nav a::after { bottom: 8px; }
  .grid-2, .grid-3 { grid-template-columns: minmax(0, 1fr); }
  .titleblock { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .titleblock > div:nth-child(2) { border-right: 0; }
  .titleblock > div:nth-child(-n+2) { border-bottom: 1px solid var(--ink); }
  .triple { grid-template-columns: minmax(0, 1fr); }
}
@media (max-width: 560px) {
  .shell { padding-left: 12px; padding-right: 12px; }
  .sheet { padding: var(--s4); }
  .pair { grid-template-columns: minmax(0, 1fr); }
  .pair.keep { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  td.share, th.share { display: none; }
  .sheet-idx a { grid-template-columns: 44px minmax(0, 1fr); }
  .sheet-idx .go { display: none; }
  .foot-in { grid-template-columns: minmax(0, 1fr); }
  .hero .iso { --iso-h: 260px; }
  .num-list li { padding-left: 46px; }
  .step details { margin-left: 0; }
  table.spec th, table.spec td { padding: 7px var(--s2); }
}
@media (min-width: 1700px) {
  body { font-size: 1.0625rem; }
}

/* ---------- Print ---------- */
@media print {
  body { background: #fff; color: #000; font-size: 11pt; }
  .site-head, .skip, .rail, .site-foot, .menu-btn, .btn-row, .iso-ctl, .no-print { display: none !important; }
  .shell { display: block; padding: 0; max-width: none; }
  .sheet { box-shadow: none; border: 1px solid #000; break-inside: avoid; page-break-inside: avoid; }
  .sheet::before, .sheet::after { display: none; }
  .titleblock { border-color: #000; }
  .step { break-inside: avoid; }
  .step details { display: block; }
  .step details > summary { display: none; }
  .step-check input { border-color: #000; }
  a { color: #000; text-decoration: none; }
  .readouts, .ro, .ro .v, .ro .k, .ro .s { background: #fff !important; color: #000 !important; text-shadow: none !important; }
  .readouts { border: 1px solid #000; }
}

/* ---------- Reduced motion: no animation, no transition, final state ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation: none !important;
    transition: none !important;
    scroll-behavior: auto !important;
  }
}

/* ---------- late additions ---------- */
.rail-list dl { margin: 0; }


.readouts.five { grid-template-columns: repeat(5, minmax(0, 1fr)); }
.readouts.five .ro.big { grid-column: 1 / -1; }
@media (max-width: 900px) { .readouts.five { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 900px) { .readouts.five .ro:last-child { grid-column: 1 / -1; } }
.fig-cap { margin-bottom: var(--s5); }
@media (max-width: 560px) { .hide-sm { display: none; } }
@media (max-width: 960px) { .rail-title { display: none; } }