/* Alle-Kiski Radon Help
   Layout: phone-first single column; full-width bands with an inner .wrap.
   On wide screens the hero splits into the reading checker (left) and the estimate form (right).
   Palette: basement-concrete neutrals, Allegheny river blue-green for actions,
   semantic gauge colors (clear / consider / act) taken from radon's own 2 and 4 pCi/L lines. */

:root {
  --bg: #f2f4f3;          /* poured concrete */
  --surface: #ffffff;
  --sunk: #e7ecea;        /* slab shadow */
  --ink: #16242a;         /* slate */
  --ink-soft: #4b5d64;
  --line: #d3dcda;
  --accent: #0d626b;      /* Allegheny river */
  --accent-strong: #094a51;
  --accent-ink: #ffffff;
  --clear: #2e7a52;
  --consider: #a86b10;
  --act: #b23a24;         /* manometer fluid */
  --pipe: #ffffff;        /* white PVC */
  --pipe-edge: #8fa3a8;
  --soil: #c9bda7;
  --soil-dot: #8a7a5f;

  --display: "Archivo", "Arial Narrow", "Helvetica Neue", Arial, sans-serif;
  --body: "Archivo", "Helvetica Neue", Arial, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;

  --step--1: 0.875rem;
  --step-0: 1.0625rem;
  --step-1: 1.25rem;
  --step-2: 1.5rem;
  --step-3: clamp(1.75rem, 1.35rem + 1.8vw, 2.5rem);
  --step-4: clamp(2.1rem, 1.5rem + 2.8vw, 3.4rem);

  --radius: 10px;
  --gutter-l: max(16px, env(safe-area-inset-left, 0px));
  --gutter-r: max(16px, env(safe-area-inset-right, 0px));
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f171a;
    --surface: #152125;
    --sunk: #1b2a2f;
    --ink: #e4ecee;
    --ink-soft: #a5b5ba;
    --line: #2a3b41;
    --accent: #5cc0c9;
    --accent-strong: #84d3da;
    --accent-ink: #0a1c1f;
    --clear: #6cc994;
    --consider: #e2ae4f;
    --act: #f07a62;
    --pipe: #dfe7e9;
    --pipe-edge: #6f858b;
    --soil: #4a4234;
    --soil-dot: #a8946d;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0f171a;
  --surface: #152125;
  --sunk: #1b2a2f;
  --ink: #e4ecee;
  --ink-soft: #a5b5ba;
  --line: #2a3b41;
  --accent: #5cc0c9;
  --accent-strong: #84d3da;
  --accent-ink: #0a1c1f;
  --clear: #6cc994;
  --consider: #e2ae4f;
  --act: #f07a62;
  --pipe: #dfe7e9;
  --pipe-edge: #6f858b;
  --soil: #4a4234;
  --soil-dot: #a8946d;
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--body);
  font-size: var(--step-0);
  line-height: 1.6;
}
img, svg { max-width: 100%; }
[hidden] { display: none !important; }

a { color: var(--accent); text-underline-offset: 0.18em; text-decoration-thickness: 1px; }
a:hover { color: var(--accent-strong); text-decoration-thickness: 2px; }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; border-radius: 4px; }

h1, h2, h3 {
  font-family: var(--display);
  font-stretch: 78%;
  font-weight: 760;
  line-height: 1.08;
  letter-spacing: -0.01em;
  text-wrap: balance;
  margin: 0;
}
h1 { font-size: var(--step-4); }
h2 { font-size: var(--step-3); }
h3 { font-size: var(--step-1); font-stretch: 85%; line-height: 1.2; }
p { margin: 0; }
.prose { display: grid; gap: 1rem; max-width: 65ch; }
.prose h2 { margin-top: 1.25rem; }
.prose h3 { margin-top: 0.5rem; }
.prose ul, .prose ol { margin: 0; padding-left: 1.25rem; display: grid; gap: 0.4rem; }
.lede { font-size: var(--step-1); color: var(--ink-soft); line-height: 1.5; max-width: 52ch; }
.eyebrow {
  font-family: var(--mono);
  font-size: var(--step--1);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-soft);
}
.unit { font-family: var(--mono); font-size: 0.92em; white-space: nowrap; }
.small { font-size: var(--step--1); color: var(--ink-soft); }

/* ---------- bands and wrappers ---------- */
.band { padding-block: clamp(2.5rem, 2rem + 3vw, 4.5rem); }
.band--sunk { background: var(--sunk); }
.band--tight { padding-block: 1.5rem; }
.wrap {
  max-width: 1120px;
  margin-inline: auto;
  padding-left: var(--gutter-l);
  padding-right: var(--gutter-r);
}
.stack { display: grid; gap: 1.25rem; }
.section-head { display: grid; gap: 0.6rem; max-width: 60ch; margin-bottom: 1.75rem; }

/* ---------- header ---------- */
.site-header { border-bottom: 1px solid var(--line); background: var(--surface); }
.site-header .wrap {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between;
  gap: 0.75rem 1.5rem; padding-block: 0.8rem;
}
.brand { display: flex; align-items: center; gap: 0.6rem; color: var(--ink); text-decoration: none; }
.brand:hover { color: var(--ink); }
.brand svg { width: 30px; height: 36px; flex: none; }
.brand-name { font-family: var(--display); font-stretch: 75%; font-weight: 800; font-size: 1.3rem; line-height: 1; letter-spacing: 0.005em; }
.brand-name small { display: block; font-family: var(--mono); font-stretch: 100%; font-weight: 500; font-size: 0.68rem; letter-spacing: 0.06em; text-transform: uppercase; color: var(--ink-soft); margin-top: 0.3rem; }
.site-nav { display: flex; flex-wrap: wrap; align-items: center; gap: 0.35rem 1.1rem; font-size: 0.95rem; }
.site-nav a { color: var(--ink); text-decoration: none; padding-block: 0.3rem; }
.site-nav a:hover { color: var(--accent); }
.site-nav a[aria-current="page"] { color: var(--accent); box-shadow: inset 0 -2px 0 var(--accent); }
.site-nav a.btn, .site-nav a.btn:hover { color: var(--accent-ink); }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 0.5rem;
  font: inherit; font-weight: 650; font-size: 1rem; line-height: 1.2;
  padding: 0.8rem 1.15rem; border-radius: 8px; border: 2px solid var(--accent);
  background: var(--accent); color: var(--accent-ink); text-decoration: none; cursor: pointer;
}
.btn:hover { background: var(--accent-strong); border-color: var(--accent-strong); color: var(--accent-ink); }
.btn--ghost { background: transparent; color: var(--accent); }
.btn--ghost:hover { background: var(--accent); color: var(--accent-ink); }
.btn--small { padding: 0.5rem 0.85rem; font-size: 0.92rem; }
.btn-row { display: flex; flex-wrap: wrap; gap: 0.75rem; align-items: center; }

/* ---------- hero ---------- */
.hero { background: var(--surface); border-bottom: 1px solid var(--line); }
.hero .wrap { display: grid; gap: 2.25rem; padding-block: clamp(2rem, 1.5rem + 3vw, 3.75rem); }
.hero-copy { display: grid; gap: 1.1rem; align-content: start; min-width: 0; }
@media (min-width: 960px) {
  .hero .wrap { grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr); align-items: start; gap: 3rem; }
}

/* ---------- reading checker ---------- */
.checker {
  background: var(--bg); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1.1rem 1.1rem 1.25rem; display: grid; gap: 0.9rem; min-width: 0;
}
.checker-head { display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: 0.25rem 1rem; }
.checker-head h2 { font-size: var(--step-1); font-stretch: 85%; }
.checker-input { display: flex; flex-wrap: wrap; align-items: center; gap: 0.6rem; }
.checker-input label { font-weight: 600; }
.reading {
  display: inline-flex; align-items: center; border: 2px solid var(--line); border-radius: 8px;
  background: var(--surface); overflow: hidden;
}
.reading:focus-within { border-color: var(--accent); }
.reading input[data-reading] {
  width: 6.5ch; border: 0; border-radius: 0; background: transparent; color: var(--ink);
  font-family: var(--mono); font-size: 1.35rem; font-weight: 500; padding: 0.35rem 0.6rem;
  font-variant-numeric: tabular-nums;
}
.reading input[data-reading]:focus, .reading input[data-reading]:focus-visible { outline: none; box-shadow: none; }
.reading span { font-family: var(--mono); font-size: 0.9rem; color: var(--ink-soft); padding-right: 0.7rem; }
.chips { display: flex; flex-wrap: wrap; gap: 0.4rem; align-items: center; }
.chips span { font-size: var(--step--1); color: var(--ink-soft); }
.chip {
  font: inherit; font-family: var(--mono); font-size: 0.85rem; padding: 0.2rem 0.55rem;
  border-radius: 999px; border: 1px solid var(--line); background: var(--surface); color: var(--ink); cursor: pointer;
}
.chip:hover { border-color: var(--accent); color: var(--accent); }

.gauge { position: relative; padding-top: 1.6rem; padding-bottom: 1.5rem; }
.gauge-track {
  height: 14px; border-radius: 7px; overflow: hidden; display: flex;
  border: 1px solid var(--line);
}
.gauge-track i { display: block; height: 100%; }
.gauge-track .z-clear { width: 10%; background: color-mix(in srgb, var(--clear) 55%, var(--surface)); }
.gauge-track .z-consider { width: 10%; background: color-mix(in srgb, var(--consider) 60%, var(--surface)); }
.gauge-track .z-act { width: 80%; background: linear-gradient(90deg, color-mix(in srgb, var(--act) 55%, var(--surface)), var(--act)); }
.gauge-ticks { position: absolute; left: 0; right: 0; bottom: 0; height: 1.3rem; font-family: var(--mono); font-size: 0.75rem; color: var(--ink-soft); }
.gauge-ticks span { position: absolute; transform: translateX(-50%); font-variant-numeric: tabular-nums; }
.gauge-ticks span:first-child { transform: none; }
.gauge-ticks span:last-child { transform: translateX(-100%); }
.gauge-line { position: absolute; top: 1.15rem; height: calc(14px + 0.9rem); width: 2px; background: var(--ink); opacity: 0.55; }
.gauge-line-label { position: absolute; top: 0; transform: translateX(-50%); font-family: var(--mono); font-size: 0.7rem; letter-spacing: 0.04em; text-transform: uppercase; color: var(--ink-soft); white-space: nowrap; }
.gauge-pointer {
  position: absolute; top: calc(1.6rem - 6px); width: 0; height: 0; transform: translateX(-50%);
  border-left: 8px solid transparent; border-right: 8px solid transparent; border-top: 10px solid var(--ink);
  transition: left 300ms ease;
}
.verdict { border-left: 4px solid var(--line); padding: 0.15rem 0 0.15rem 0.85rem; display: grid; gap: 0.35rem; }
.verdict strong { font-family: var(--display); font-stretch: 85%; font-size: var(--step-1); line-height: 1.25; }
.verdict[data-level="clear"] { border-color: var(--clear); }
.verdict[data-level="consider"] { border-color: var(--consider); }
.verdict[data-level="act"], .verdict[data-level="high"], .verdict[data-level="veryhigh"] { border-color: var(--act); }
.verdict[data-level="clear"] strong { color: var(--clear); }
.verdict[data-level="consider"] strong { color: var(--consider); }
.verdict[data-level="act"] strong, .verdict[data-level="high"] strong, .verdict[data-level="veryhigh"] strong { color: var(--act); }

/* ---------- estimate form ---------- */
.estimate {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: clamp(1.1rem, 0.9rem + 1vw, 1.6rem); display: grid; gap: 1rem; min-width: 0;
  box-shadow: 0 1px 0 var(--line), 0 18px 40px -28px color-mix(in srgb, var(--ink) 45%, transparent);
  scroll-margin-top: 1rem;
}
.estimate h2 { font-size: var(--step-2); font-stretch: 82%; }
.form-grid { display: grid; gap: 0.85rem; }
@media (min-width: 560px) { .form-grid--2 { grid-template-columns: 1fr 1fr; } }
.field { display: grid; gap: 0.3rem; min-width: 0; }
.field label { font-weight: 600; font-size: 0.95rem; }
.field .hint { font-size: 0.82rem; color: var(--ink-soft); font-weight: 400; }
input[type="text"], input[type="tel"], input[type="email"], input[type="number"], input[type="date"], select, textarea {
  width: 100%; font: inherit; font-size: 1rem; color: var(--ink); background: var(--bg);
  border: 1.5px solid var(--line); border-radius: 7px; padding: 0.62rem 0.7rem; min-width: 0;
}
input:focus, select:focus, textarea:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 22%, transparent); }
textarea { min-height: 5.5rem; resize: vertical; }
.consent { display: grid; grid-template-columns: auto 1fr; gap: 0.6rem; align-items: start; font-size: 0.86rem; color: var(--ink-soft); line-height: 1.45; }
.consent input { width: 1.15rem; height: 1.15rem; margin-top: 0.15rem; accent-color: var(--accent); }
.form-note { font-size: 0.85rem; color: var(--ink-soft); }
.preview-note {
  font-size: 0.85rem; border: 1px dashed var(--consider); color: var(--ink);
  background: color-mix(in srgb, var(--consider) 12%, var(--surface)); border-radius: 8px; padding: 0.6rem 0.75rem;
}

/* ---------- facts row ---------- */
.facts { display: grid; gap: 1rem; }
@media (min-width: 760px) { .facts { grid-template-columns: repeat(3, minmax(0, 1fr)); } }
.fact { display: grid; gap: 0.35rem; align-content: start; padding-top: 0.9rem; border-top: 2px solid var(--ink); min-width: 0; }
.fact b { font-family: var(--display); font-stretch: 78%; font-size: var(--step-3); line-height: 1; font-weight: 780; }
.fact p { color: var(--ink-soft); font-size: 0.97rem; }
.fact a { font-size: var(--step--1); }

/* ---------- steps ---------- */
.steps { list-style: none; margin: 0; padding: 0; display: grid; gap: 1.25rem; counter-reset: step; }
@media (min-width: 760px) { .steps { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1.75rem; } }
.steps li { counter-increment: step; display: grid; gap: 0.5rem; align-content: start; min-width: 0; }
.steps li::before {
  content: counter(step); font-family: var(--mono); font-weight: 500; font-size: 0.9rem;
  width: 2rem; height: 2rem; display: grid; place-items: center; border-radius: 50%;
  border: 2px solid var(--accent); color: var(--accent);
}
.steps p { color: var(--ink-soft); }

/* ---------- system diagram ---------- */
.system { display: grid; gap: 1.75rem; align-items: start; }
@media (min-width: 900px) { .system { grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr); gap: 2.5rem; } }
.diagram { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 0.75rem; min-width: 0; }
.diagram svg { display: block; width: 100%; height: auto; }
.legend { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.75rem; }
.legend li { display: grid; grid-template-columns: 1.8rem 1fr; gap: 0.6rem; align-items: start; }
.legend b { font-family: var(--mono); font-weight: 500; font-size: 0.85rem; width: 1.6rem; height: 1.6rem; border-radius: 50%; display: grid; place-items: center; background: var(--ink); color: var(--bg); }
.legend p { color: var(--ink-soft); }
.legend strong { color: var(--ink); }
.d-soil { fill: var(--soil); }
.d-dot { fill: var(--soil-dot); }
.d-slab { fill: var(--sunk); stroke: var(--pipe-edge); stroke-width: 1.5; }
.d-gravel { fill: color-mix(in srgb, var(--soil) 70%, var(--surface)); }
.d-wall { fill: var(--surface); stroke: var(--ink-soft); stroke-width: 2; }
.d-roof { fill: var(--sunk); stroke: var(--ink-soft); stroke-width: 2; }
.d-sky { fill: var(--bg); }
.d-pipe { fill: none; stroke: var(--pipe-edge); stroke-width: 13; stroke-linejoin: round; stroke-linecap: butt; }
.d-pipe-core { fill: none; stroke: var(--pipe); stroke-width: 9; stroke-linejoin: round; stroke-linecap: butt; }
.d-fan { fill: var(--surface); stroke: var(--ink); stroke-width: 2; }
.d-flow { fill: none; stroke: var(--act); stroke-width: 2; stroke-dasharray: 4 5; }
.d-arrow { fill: var(--act); }
.d-mano { fill: var(--surface); stroke: var(--ink); stroke-width: 1.5; }
.d-fluid { fill: var(--act); }
.d-mark { fill: var(--ink); }
.d-mark-text { fill: var(--bg); font-family: var(--mono); font-size: 13px; font-weight: 500; }
.d-label { fill: var(--ink-soft); font-family: var(--mono); font-size: 12px; }
.d-ground { stroke: var(--ink-soft); stroke-width: 2; }

/* ---------- table ---------- */
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
table { border-collapse: collapse; width: 100%; min-width: 520px; font-size: 0.97rem; }
th, td { text-align: left; padding: 0.7rem 0.9rem; border-bottom: 1px solid var(--line); vertical-align: top; }
th { font-family: var(--mono); font-weight: 500; font-size: 0.78rem; letter-spacing: 0.05em; text-transform: uppercase; color: var(--ink-soft); background: var(--sunk); }
td.num { font-family: var(--mono); font-variant-numeric: tabular-nums; white-space: nowrap; }
tr:last-child td { border-bottom: 0; }
table.fit { min-width: 0; }
@media (max-width: 480px) { table.fit th, table.fit td { padding: 0.6rem 0.55rem; font-size: 0.92rem; } }

/* ---------- towns ---------- */
.towns { display: grid; gap: 1.5rem; }
@media (min-width: 700px) { .towns { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (min-width: 1000px) { .towns { grid-template-columns: repeat(4, minmax(0, 1fr)); } }
.county { display: grid; gap: 0.5rem; align-content: start; min-width: 0; }
.county h3 { font-size: 1.05rem; }
.county ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.2rem; color: var(--ink-soft); }
.county p { font-size: 0.88rem; color: var(--ink-soft); border-left: 3px solid var(--consider); padding-left: 0.6rem; }

/* ---------- FAQ ---------- */
.faq { display: grid; gap: 0; border-top: 1px solid var(--line); max-width: 75ch; }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary {
  cursor: pointer; list-style: none; padding: 1rem 2rem 1rem 0; position: relative;
  font-weight: 650; font-size: 1.05rem;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; position: absolute; right: 0.25rem; top: 0.85rem; font-family: var(--mono); font-size: 1.2rem; color: var(--accent); }
.faq details[open] summary::after { content: "\2212"; }
.faq .answer { padding: 0 0 1.1rem; color: var(--ink-soft); display: grid; gap: 0.6rem; max-width: 65ch; }

/* ---------- article pages ---------- */
.page-head { background: var(--surface); border-bottom: 1px solid var(--line); }
.page-head .wrap { padding-block: clamp(2rem, 1.6rem + 2vw, 3rem); display: grid; gap: 0.9rem; }
.crumbs { font-size: var(--step--1); color: var(--ink-soft); }
.crumbs a { color: var(--ink-soft); }
.article { display: grid; gap: 2.5rem; }
@media (min-width: 1000px) { .article { grid-template-columns: minmax(0, 1fr) 360px; gap: 3.5rem; align-items: start; } }
.aside { display: grid; gap: 1rem; min-width: 0; }
@media (min-width: 1000px) { .aside { position: sticky; top: 1.25rem; } }
.callout {
  border: 1px solid var(--line); border-left: 4px solid var(--accent); background: var(--surface);
  border-radius: 8px; padding: 0.9rem 1rem; display: grid; gap: 0.4rem;
}
.callout--act { border-left-color: var(--act); }
.sources { font-size: 0.88rem; color: var(--ink-soft); display: grid; gap: 0.4rem; }
.sources ul { margin: 0; padding-left: 1.1rem; display: grid; gap: 0.25rem; }

/* ---------- footer ---------- */
.site-footer { border-top: 1px solid var(--line); background: var(--surface); }
.site-footer .wrap { padding-block: 2.5rem 6rem; display: grid; gap: 1.25rem; }
@media (min-width: 760px) { .site-footer .wrap { padding-block: 2.5rem; } }
.footer-grid { display: grid; gap: 1.5rem; }
@media (min-width: 760px) { .footer-grid { grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr); } }
.footer-links { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.35rem; }
.disclosure { font-size: 0.88rem; color: var(--ink-soft); max-width: 70ch; }

/* ---------- mobile estimate bar ---------- */
.mobile-cta {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 20;
  padding: 0.6rem var(--gutter-r) calc(0.6rem + env(safe-area-inset-bottom, 0px)) var(--gutter-l);
  background: var(--surface); border-top: 1px solid var(--line);
  display: flex; gap: 0.75rem; align-items: center; justify-content: space-between;
  box-shadow: 0 -10px 24px -18px color-mix(in srgb, var(--ink) 50%, transparent);
}
.mobile-cta p { font-size: 0.85rem; color: var(--ink-soft); line-height: 1.3; }
@media (min-width: 760px) { .mobile-cta { display: none; } }

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; scroll-behavior: auto !important; }
}