:root {
  --ground: #eef0f3;
  --panel: #ffffff;
  --panel-2: #f6f7f9;
  --ink: #141b26;
  --ink-soft: #475569;
  --navy: #1b2f4b;
  --navy-2: #122134;
  --line: #d5dae2;
  --line-hard: #b9c1cd;
  --amber: #b06e0d;
  --slate: #5a6b7d;
  --red: #a32a24;
  --green: #1f6b52;
  --rule: rgba(27, 47, 75, 0.08);
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "Cascadia Mono", "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --max: 1120px;
  --r: 2px;
}

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

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

body {
  margin: 0;
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.62;
  background-color: var(--ground);
  background-image: linear-gradient(180deg, var(--rule) 1px, transparent 1px);
  background-size: 100% 34px;
}

a { color: var(--navy); text-underline-offset: 3px; text-decoration-thickness: 1px; }
a:hover { color: var(--amber); }

.skip {
  position: absolute; left: -9999px; top: 0; z-index: 40;
  background: var(--navy); color: #fff; padding: 10px 14px;
}
.skip:focus { left: 0; }

.top {
  position: sticky; top: 0; z-index: 30;
  background: var(--navy-2);
  color: #e9edf3;
  border-bottom: 4px solid var(--amber);
}
.bar {
  max-width: var(--max); margin: 0 auto; padding: 10px 20px;
  display: flex; align-items: center; gap: 18px; flex-wrap: wrap;
}
.brand {
  color: #fff; text-decoration: none; font-weight: 700;
  letter-spacing: 0.14em; text-transform: uppercase; font-size: 13px;
  display: inline-flex; align-items: center; gap: 9px;
}
.mark {
  display: inline-grid; place-items: center;
  width: 28px; height: 28px; background: var(--amber); color: #191206;
  font: 700 12px/1 var(--mono); letter-spacing: 0.04em;
}
.menu { display: flex; gap: 14px; flex-wrap: wrap; margin-left: auto; }
.menu a {
  color: #cdd6e2; text-decoration: none; font-size: 13px;
  letter-spacing: 0.06em; text-transform: uppercase;
}
.menu a:hover, .menu a[aria-current="page"] { color: #fff; border-bottom: 2px solid var(--amber); }
.btn {
  display: inline-block; background: var(--amber); color: #191206;
  font-weight: 700; font-size: 14px; letter-spacing: 0.03em;
  padding: 9px 15px; text-decoration: none; border-radius: var(--r);
  transition: transform 160ms var(--ease), background-color 160ms var(--ease);
}
.btn:hover { background: #c67c10; color: #191206; transform: translateY(-1px); }
.top .btn { margin-left: 6px; }
.ghost {
  display: inline-block; margin-left: 12px; padding: 9px 15px;
  border: 1px solid var(--line-hard); color: var(--navy); text-decoration: none;
  font-size: 14px; font-weight: 600;
}

.shell { max-width: var(--max); margin: 0 auto; padding: 0 20px 56px; }

.disc {
  margin: 22px 0 26px; padding: 14px 16px 14px 20px;
  background: var(--panel-2); border-left: 4px solid var(--navy);
  font-size: 14px; color: var(--ink-soft);
}
.disc b { color: var(--ink); }
.disc code { font-family: var(--mono); font-size: 12px; background: #e6e9ee; padding: 1px 5px; }

.page-hero {
  position: relative;
  border: 1px solid var(--line-hard);
  background: var(--panel);
  padding: 26px 26px 24px 40px;
  box-shadow: -7px 0 0 -1px var(--navy);
}
.crumb-line {
  font: 600 11px/1.4 var(--mono); letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--slate); margin-bottom: 14px;
}
.eyebrow {
  font: 700 11px/1.4 var(--mono); letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--amber); margin-bottom: 10px;
}
h1 {
  font-family: var(--sans);
  font-size: clamp(28px, 4.4vw, 46px);
  line-height: 1.06; letter-spacing: -0.01em; text-transform: uppercase;
  margin: 0 0 14px; font-weight: 800;
}
.lede { font-size: 19px; color: var(--ink-soft); margin: 0; max-width: 66ch; }
.hero-grid { display: grid; gap: 26px; }
.hero-cta { margin-top: 20px; }

h2 {
  font-size: clamp(20px, 2.6vw, 27px); line-height: 1.2; font-weight: 800;
  text-transform: uppercase; letter-spacing: 0.01em;
  margin: 40px 0 12px; padding-top: 14px; border-top: 3px solid var(--navy);
}
h3 { font-size: 17px; margin: 22px 0 6px; font-weight: 700; }
p { margin: 0 0 14px; }
ul, ol { margin: 0 0 16px; padding-left: 22px; }
li { margin-bottom: 7px; }
code, kbd { font-family: var(--mono); font-size: 0.92em; }

.answer {
  margin: 26px 0 6px; padding: 16px 18px;
  background: var(--panel-2); border: 1px solid var(--line-hard); border-left: 4px solid var(--amber);
  font-size: 17px;
}
.answer b {
  display: block; font: 700 11px/1.4 var(--mono); letter-spacing: 0.16em;
  text-transform: uppercase; color: var(--amber); margin-bottom: 8px;
}

table {
  width: 100%; border-collapse: collapse; margin: 20px 0 24px;
  font-size: 15px; background: var(--panel); border: 1px solid var(--line-hard);
}
caption {
  caption-side: top; text-align: left; padding: 0 0 8px;
  font: 700 11px/1.4 var(--mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--slate);
}
th, td { text-align: left; vertical-align: top; padding: 10px 12px; border-bottom: 1px solid var(--line); }
thead th {
  background: var(--navy); color: #eef2f7;
  font: 700 11px/1.4 var(--mono); letter-spacing: 0.1em; text-transform: uppercase;
}
tbody tr:nth-child(even) { background: var(--panel-2); }
tbody tr:last-child td { border-bottom: 0; }
td.num, th.num { font-family: var(--mono); white-space: nowrap; }

.chip {
  display: inline-block; padding: 2px 9px; border-radius: 999px;
  font: 700 11px/1.6 var(--mono); letter-spacing: 0.06em; text-transform: uppercase;
  border: 1px solid currentColor;
}
.chip-ok { color: var(--green); background: #e8f3ee; }
.chip-warn { color: var(--amber); background: #f8f1e3; }
.chip-stop { color: var(--red); background: #f7eae9; }
.chip-neutral { color: var(--slate); background: #eef1f5; }

.note {
  margin: 22px 0; padding: 14px 16px; background: #f7eae9;
  border: 1px solid #e2c1bd; border-left: 4px solid var(--red); font-size: 15px;
}
.note-tag {
  display: block; font: 700 11px/1.4 var(--mono); letter-spacing: 0.14em;
  text-transform: uppercase; color: var(--red); margin-bottom: 6px;
}

.calc {
  margin: 20px 0; padding: 14px 16px; background: var(--navy-2); color: #e9edf3;
  font-family: var(--mono); font-size: 14px; line-height: 1.9; overflow-x: auto;
}
.calc b { color: #ffce7a; font-weight: 700; }

.ctaband {
  margin: 30px 0; padding: 18px 20px; background: var(--panel);
  border: 1px solid var(--line-hard); border-top: 4px solid var(--amber);
  display: flex; align-items: center; gap: 18px; flex-wrap: wrap; justify-content: space-between;
}
.ctaband p { margin: 0; max-width: 62ch; font-size: 15px; color: var(--ink-soft); }

/* The notch spine: the draughtsman's margin of small solid ticks that runs down the left edge of
the sheet. It is decoration only and it disappears on narrow screens. */
.shell { position: relative; padding-left: 44px; }
.shell::before {
  content: ""; position: absolute; left: 14px; top: 0; bottom: 0; width: 6px;
  background-image: repeating-linear-gradient(
    180deg, var(--line-hard) 0 7px, transparent 7px 27px
  );
}

/* SIGNATURE COMPONENT: the ceiling rail. Each row is one request against one ceiling. The solid
bar is the stake the operator accepted; the hatched remainder is what the ceiling refused; the
hard line across the track is the ceiling itself. */
.ceiling-rail {
  margin: 24px 0; border: 1px solid var(--line-hard); background: var(--panel);
}
.rail-cap {
  background: var(--navy); color: #eef2f7; padding: 9px 14px;
  font: 700 11px/1.4 var(--mono); letter-spacing: 0.12em; text-transform: uppercase;
}
.rail-body { padding: 6px 14px 12px; }
.rail-row { padding: 13px 0 11px; border-bottom: 1px dashed var(--line-hard); }
.rail-row:last-child { border-bottom: 0; }
.rail-meta {
  display: flex; justify-content: space-between; gap: 12px; align-items: baseline;
  margin-bottom: 8px; font-family: var(--mono); font-size: 12px; letter-spacing: 0.06em;
}
.rail-tag { font-weight: 700; text-transform: uppercase; color: var(--slate); }
.rail-num { color: var(--ink-soft); }
.rail-track {
  position: relative; height: 20px; background: var(--panel-2);
  border: 1px solid var(--line); overflow: hidden;
}
.rail-bar { position: absolute; left: 0; top: 0; bottom: 0; background: var(--green); }
.rail-ghost {
  position: absolute; top: 0; bottom: 0; background-color: #f7eae9;
  background-image: repeating-linear-gradient(
    135deg, #e6bdb8 0 3px, transparent 3px 9px
  );
}
.ceil-line { position: absolute; top: -1px; bottom: -1px; width: 3px; background: var(--amber); }
.w-100 { width: 100%; } .w-72 { width: 72%; } .w-40 { width: 40%; }
.w-26 { width: 26%; } .w-14 { width: 14%; } .w-0 { width: 0; }
.rail-row p { margin: 8px 0 0; font-size: 14px; color: var(--ink-soft); }
.ceil-open .rail-tag { color: var(--green); }
.ceil-clamped .rail-tag { color: var(--amber); }
.ceil-zero .rail-tag, .ceil-closed .rail-tag { color: var(--red); }
.ceil-closed { background: #faf2f1; }

/* SIGNATURE COMPONENT: the limit ladder. Steps of a life cycle, each rung one notch lower. */
.limit-ladder { margin: 24px 0; border: 1px solid var(--line-hard); background: var(--panel); padding: 14px; }
.ladder-cap {
  font: 700 11px/1.4 var(--mono); letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--slate); margin-bottom: 12px;
}
.rung { display: grid; grid-template-columns: 132px 1fr; gap: 12px; align-items: center; margin-bottom: 9px; }
.rung-step {
  font: 700 11px/1.5 var(--mono); letter-spacing: 0.06em; text-transform: uppercase; color: var(--navy);
}
.rung-track { height: 13px; background: var(--panel-2); border: 1px solid var(--line); position: relative; }
.rung-bar { position: absolute; left: 0; top: 0; bottom: 0; background: var(--navy); }
.rung-bar.amber { background: var(--amber); }
.rung-bar.red { background: var(--red); }
.rung-note { grid-column: 2; font-size: 13px; color: var(--ink-soft); margin: -3px 0 6px; }

.steps { counter-reset: step; list-style: none; padding: 0; margin: 22px 0; }
.steps li {
  counter-increment: step; position: relative; padding: 13px 14px 13px 52px;
  background: var(--panel); border: 1px solid var(--line); margin-bottom: 8px;
}
.steps li::before {
  content: counter(step, decimal-leading-zero); position: absolute; left: 14px; top: 13px;
  font: 700 12px/1 var(--mono); color: var(--amber); letter-spacing: 0.04em;
}
.steps strong { display: block; margin-bottom: 3px; }
.steps p { margin: 0; font-size: 15px; color: var(--ink-soft); }

.flag-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 12px; margin: 22px 0; }
.flag { background: var(--panel); border: 1px solid var(--line-hard); border-top: 3px solid var(--slate); padding: 13px 15px; }
.flag h3 { margin: 0 0 6px; font-size: 15px; text-transform: uppercase; letter-spacing: 0.03em; }
.flag p { margin: 0; font-size: 14px; color: var(--ink-soft); }
.flag.risk { border-top-color: var(--amber); }
.flag.stop { border-top-color: var(--red); }
.flag.keep { border-top-color: var(--green); }

.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 12px; margin: 24px 0; }
.stat { background: var(--panel); border: 1px solid var(--line-hard); padding: 14px 16px; }
.stat b { display: block; font: 700 25px/1.1 var(--mono); color: var(--navy); margin-bottom: 6px; }
.stat span { font-size: 13px; color: var(--ink-soft); }

.cklist { list-style: none; padding: 0; margin: 20px 0; }
.cklist li { position: relative; padding-left: 30px; margin-bottom: 9px; }
.cklist li::before {
  content: ""; position: absolute; left: 0; top: 5px; width: 11px; height: 11px;
  border: 2px solid var(--navy);
}
.cklist li.done::before { background: var(--green); border-color: var(--green); }

.fig { margin: 24px 0; padding: 14px; background: var(--panel); border: 1px solid var(--line-hard); }
.fig svg { width: 100%; height: auto; display: block; }
.fig figcaption {
  margin-top: 10px; font: 600 11px/1.6 var(--mono); letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--slate);
}

.faqlist { margin: 20px 0 26px; }
.faqlist details {
  background: var(--panel); border: 1px solid var(--line-hard); margin-bottom: 8px; padding: 12px 15px;
}
.faqlist summary { cursor: pointer; font-weight: 700; font-size: 16px; }
.faqlist details[open] summary { color: var(--amber); }
.faqlist p { margin: 10px 0 2px; font-size: 15px; color: var(--ink-soft); }

ol.fn { font-size: 14px; color: var(--ink-soft); }
sup.fnref { font-family: var(--mono); font-size: 11px; color: var(--amber); }

.footer { background: var(--navy-2); color: #c8d2df; margin-top: 40px; border-top: 4px solid var(--amber); }
.foot-grid {
  max-width: var(--max); margin: 0 auto; padding: 28px 20px 6px;
  display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 24px;
}
.footer strong { display: block; color: #fff; font-size: 12px; letter-spacing: 0.12em; text-transform: uppercase; margin-bottom: 9px; }
.footer a { display: block; color: #c8d2df; text-decoration: none; font-size: 14px; margin-bottom: 6px; }
.footer a:hover { color: #ffce7a; }
.footer .brand { display: inline-flex; margin-bottom: 8px; }
.footer p { font-size: 13px; line-height: 1.6; }
.footer .fine {
  max-width: var(--max); margin: 0 auto; padding: 14px 20px 28px;
  border-top: 1px solid rgba(255,255,255,0.12); color: #a9b6c6; font-size: 12.5px;
}

@media (max-width: 720px) {
  .shell { padding-left: 22px; }
  .shell::before { display: none; }
  .bar { gap: 10px; }
  .menu { margin-left: 0; gap: 11px; }
  .page-hero { padding: 20px 18px 20px 22px; box-shadow: -5px 0 0 -1px var(--navy); }
  .rung { grid-template-columns: 1fr; gap: 5px; }
  .rung-note { grid-column: 1; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition-duration: 1ms !important; animation-duration: 1ms !important; }
  .btn:hover { transform: none; }
}