/* 00  Core — resets and behaviour hooks only. Every visual decision for this
       site lives in the sections below, starting with the design tokens.    */

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; }
img, svg, iframe, video { display: block; max-width: 100%; }
img { height: auto; }
iframe { border: 0; }
figure { margin: 0; }
[hidden] { display: none !important; }
:where(a, button, input, select, textarea, summary, [tabindex]):focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; }
.skip-link { position: absolute; left: 0.5rem; top: 0.5rem; z-index: 999; transform: translateY(-160%); padding: 0.8rem 1.2rem; background: #000; color: #fff; font-weight: 700; text-decoration: none; }
.skip-link:focus { transform: none; }
.visually-hidden { position: absolute !important; width: 1px; height: 1px; margin: -1px; padding: 0; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }
.nav-toggle .icon-close, .nav-toggle[aria-expanded="true"] .icon-open { display: none; }
.nav-toggle[aria-expanded="true"] .icon-close { display: block; }
summary { cursor: pointer; }
summary::-webkit-details-marker { display: none; }
.hp-field { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }
.field { display: flex; flex-direction: column; gap: 0.3rem; min-width: 0; }
.field__error { margin: 0; min-height: 1rem; font-size: 0.82rem; font-weight: 700; color: var(--err); }
.field.is-invalid :where(input, select, textarea) { border-color: var(--err); }
.form-status { min-height: 1.2rem; font-weight: 700; }
.form-status.is-error { color: var(--err); }
.form-status.is-ok { color: var(--ok); }
.img-placeholder { display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 0.25rem; width: 100%; padding: 1rem; text-align: center; font-size: 0.72rem; letter-spacing: 0.08em; text-transform: uppercase; line-height: 1.5; }
.img-placeholder b { display: block; font-size: 0.92rem; letter-spacing: 0; text-transform: none; word-break: break-all; }
:target { scroll-margin-top: 120px; }
@media (prefers-reduced-motion: no-preference) { html { scroll-behavior: smooth; } }
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; scroll-behavior: auto !important; } }

/* ==========================================================================
   Black Oak HVAC Facility — blackoakhvac.xyz
   THE DEVICE: the split. Full-bleed sections divided hard down the middle,
   one half a panel and one half the field, edge to edge with no container.
   A dark site on purpose — the second in this workspace, and the brand
   supports it. Contrast checked against WCAG AA throughout.
   01 Tokens · 02 Base · 03 Header · 04 Edge tab · 05 Buttons
   06 Hero · 07 Page heads · 08 The split · 09 Blocks
   10 Pressure (signature) · 11 FAQ · 12 Form & contact · 13 Footer · 14 Images
   ========================================================================== */

/* 01 Tokens */
:root {
  --bg: #141414; --panel: #1e1e1e; --panel-2: #262626; --line: #333333;
  --lime: #a3e635; --lime-dark: #7fb327; --lime-ink: #10170a;
  --ink: #ffffff; --text: #c9c9c4; --muted: #8f8f88;
  --focus: #a3e635; --err: #ff8a80;
  --disp: "Recursive", "Segoe UI", system-ui, sans-serif;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --f-sm: 0.91rem; --f-xs: 0.77rem; --f0: clamp(1rem, 0.97rem + 0.16vw, 1.06rem);
  --f1: clamp(1.14rem, 1.03rem + 0.5vw, 1.36rem);
  --f2: clamp(1.6rem, 1.3rem + 1.5vw, 2.3rem); --f3: clamp(1.95rem, 1.45rem + 2.5vw, 3.1rem);
  --r: 2px; --wrap: 1180px; --pad-y: clamp(2.6rem, 2.1rem + 3vw, 4.4rem);
  --split-pad: clamp(1.6rem, 1.15rem + 2.4vw, 3.4rem);
}

/* 02 Base */
body { background: var(--bg); color: var(--text); font-family: var(--sans); font-size: var(--f0); line-height: 1.68; }
h1, h2, h3 { margin: 0 0 0.45em; font-family: var(--disp); color: var(--ink); font-weight: 700; line-height: 1.16; letter-spacing: -0.024em; text-wrap: balance; }
h1 { font-size: var(--f3); }
h2 { font-size: var(--f2); }
h3 { font-size: var(--f1); }
p { margin: 0 0 1em; max-width: 62ch; }
p:last-child { margin-bottom: 0; }
a { color: var(--lime); text-underline-offset: 3px; }
a:hover { color: #fff; }
strong, b { color: var(--ink); font-weight: 700; }
ul, ol { margin: 0 0 1em; padding-left: 1.2em; }
.wrap { width: min(100% - 2rem, var(--wrap)); margin-inline: auto; }
.lbl { display: block; margin-bottom: 0.5rem; font-family: var(--disp); font-size: 0.7rem; font-weight: 700; letter-spacing: 0.2em; text-transform: uppercase; color: var(--lime); }
.mt { margin-top: 2rem; }

/* 03 Header */
.hd { position: sticky; top: 0; z-index: 30; background: var(--bg); border-bottom: 1px solid var(--line); }
.hd .wrap { display: flex; align-items: center; gap: 0.6rem; min-height: 56px; }
.bo-logo { display: inline-flex; align-items: center; gap: 0.5rem; margin-right: auto; color: var(--ink); text-decoration: none; }
.bo-logo svg { width: 25px; height: 25px; flex: none; }
.bo-logo span { display: none; }
.bo-logo b { display: block; font-family: var(--disp); font-size: 1.04rem; font-weight: 700; letter-spacing: -0.03em; color: var(--ink); }
.bo-logo small { display: block; margin-top: -0.1em; font-size: 0.52rem; font-weight: 700; letter-spacing: 0.18em; text-transform: uppercase; color: var(--lime); }
.hd__tel { display: inline-flex; align-items: center; gap: 0.35rem; color: var(--ink); font-family: var(--disp); font-weight: 700; font-size: 0.92rem; text-decoration: none; white-space: nowrap; }
.hd__tel svg { width: 15px; height: 15px; color: var(--lime); flex: none; }
.hd__tel:hover { color: var(--lime); }
.nav-toggle { display: inline-flex; align-items: center; justify-content: center; flex: none; width: 38px; height: 38px; padding: 0; border: 1px solid var(--line); border-radius: var(--r); background: transparent; color: var(--ink); cursor: pointer; }
.nav-toggle svg { width: 18px; height: 18px; }
.bonav { display: none; }
@media (max-width: 979px) {
  .hd .btn { display: none; }
  .bonav { position: absolute; top: 100%; left: 0; right: 0; flex-direction: column; padding: 0.3rem 1rem 1.2rem; background: var(--bg); border-bottom: 1px solid var(--line); }
  .bonav.is-open { display: flex; }
  .bonav a { padding: 0.85rem 0.2rem; border-bottom: 1px solid var(--line); color: var(--ink); font-family: var(--disp); font-size: 1.06rem; font-weight: 700; text-decoration: none; }
  .bonav a[aria-current="page"] { color: var(--lime); }
}
@media (min-width: 420px) { .bo-logo span { display: block; } }
@media (min-width: 980px) {
  .hd .wrap { min-height: 68px; gap: 1.4rem; }
  .nav-toggle { display: none; }
  .bonav { display: flex; gap: 1.4rem; }
  .bonav a { padding: 0.3rem 0; color: var(--muted); font-weight: 600; text-decoration: none; border-bottom: 2px solid transparent; white-space: nowrap; }
  .bonav a:hover { color: var(--ink); }
  .bonav a[aria-current="page"] { color: var(--ink); border-bottom-color: var(--lime); }
  .hd__tel { margin-left: auto; font-size: 1rem; }
}

/* 04 Edge tab — phones only; a lime tab down the left edge of the screen */
.edge { position: fixed; left: 0; top: 50%; z-index: 40; transform: translateY(-50%); padding: 1.1rem 0.4rem; border-radius: 0 var(--r) var(--r) 0; background: var(--lime); color: var(--lime-ink); font-family: var(--disp); font-size: 0.78rem; font-weight: 700; letter-spacing: 0.16em; text-transform: uppercase; text-decoration: none; writing-mode: vertical-rl; box-shadow: 2px 0 14px rgba(0,0,0,0.5); }
.edge:hover { background: #fff; color: var(--lime-ink); }
@media (min-width: 980px) { .edge { display: none; } }

/* 05 Buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 0.5rem; padding: 0.68rem 1.3rem; border: 0; border-radius: var(--r); background: var(--lime); color: var(--lime-ink); font-family: var(--disp); font-size: 0.97rem; font-weight: 700; line-height: 1.3; text-decoration: none; white-space: nowrap; cursor: pointer; transition: background-color 0.18s, color 0.18s; }
.btn:hover { background: #fff; color: var(--lime-ink); }
.btn svg { width: 1.05em; height: 1.05em; flex: none; }
.btn--line { background: transparent; color: var(--ink); box-shadow: inset 0 0 0 2px #5a5a5a; }
.btn--line:hover { background: var(--ink); color: var(--bg); }
.btn--white { background: #fff; color: var(--bg); }
.btn--white:hover { background: var(--lime); color: var(--lime-ink); }
@media (max-width: 460px) { .btn { white-space: normal; text-align: center; } }
.btns { display: flex; flex-wrap: wrap; gap: 0.6rem; margin-top: 1.4rem; }

/* 06 Hero */
.hero { padding-block: clamp(2.6rem, 2rem + 3vw, 4.4rem); border-bottom: 1px solid var(--line); }
.hero h1 { max-width: 18ch; }
.hero p.lede { font-size: var(--f1); line-height: 1.5; color: #ddddd8; max-width: 52ch; }

/* 07 Page heads */
.phead { padding-block: clamp(2rem, 1.6rem + 2.2vw, 3.2rem); background: var(--panel); border-bottom: 1px solid var(--line); }
.phead h1 { max-width: 20ch; }
.phead p { font-size: 1.03rem; max-width: 58ch; }
.crumbs { display: flex; flex-wrap: wrap; gap: 0.45rem; margin: 0 0 0.9rem; padding: 0; list-style: none; font-size: 0.83rem; }
.crumbs li + li::before { content: "/"; margin-right: 0.45rem; color: var(--lime); }
.crumbs a { color: var(--ink); }

/* 08 The split — the device */
.split2 { display: grid; border-bottom: 1px solid var(--line); }
@media (min-width: 900px) { .split2 { grid-template-columns: 1fr 1fr; } }
.split2 > * { min-width: 0; padding: var(--split-pad); }
.split2__a { background: var(--panel); }
.split2__b { background: var(--bg); border-top: 1px solid var(--line); }
@media (min-width: 900px) { .split2__b { border-top: 0; border-left: 1px solid var(--line); } }
@media (min-width: 900px) { .split2--flip .split2__a { order: 2; border-left: 1px solid var(--line); } .split2--flip .split2__b { border-left: 0; } }
.split2--lime .split2__a { background: var(--lime); color: var(--lime-ink); }
.split2--lime .split2__a h2, .split2--lime .split2__a h3, .split2--lime .split2__a b { color: var(--lime-ink); }
.split2--lime .split2__a a:not(.btn) { color: var(--lime-ink); }
.split2--lime .split2__a .lbl { color: #2f4a10; }
.split2--lime .split2__a .btn { background: var(--lime-ink); color: var(--lime); }
.split2--lime .split2__a .btn:hover { background: #fff; color: var(--lime-ink); }
.split2__inner { max-width: 34rem; }
@media (min-width: 900px) { .split2__a .split2__inner { margin-left: auto; } }
.split2 .num { display: block; margin-bottom: 0.6rem; font-family: var(--disp); font-size: clamp(2.4rem, 1.9rem + 2.4vw, 3.6rem); font-weight: 700; line-height: 0.9; color: var(--lime); }
.split2--lime .split2__a .num { color: var(--lime-ink); }
.split2 ul { margin: 0.8rem 0 0; padding-left: 1.05em; font-size: var(--f-sm); }
.split2 li { margin-bottom: 0.3rem; }
.split2 img, .split2 .img-placeholder { display: block; width: 100%; aspect-ratio: 4 / 3; object-fit: cover; }
.split2--fig .split2__b { padding: 0; }

/* 09 Blocks */
.sec { padding-block: var(--pad-y); }
.sec--bg { background: var(--bg); }
.sec--panel { background: var(--panel); }
.sec--lime { background: var(--lime); color: var(--lime-ink); }
.sec--lime h2, .sec--lime h3, .sec--lime b { color: var(--lime-ink); }
.sec--lime .lbl { color: #2f4a10; }
.sec--lime a:not(.btn) { color: var(--lime-ink); }
.sec--lime .btn { background: var(--lime-ink); color: var(--lime); }
.sec--lime .btn:hover { background: #fff; color: var(--lime-ink); }
.head { max-width: 640px; }
.plain { margin: 1.3rem 0 0; padding: 0; list-style: none; border-top: 1px solid var(--line); }
.plain li { padding: 0.85rem 0; border-bottom: 1px solid var(--line); }
.sec--lime .plain, .sec--lime .plain li { border-color: rgba(16,23,10,0.25); }
.plain b { display: block; font-family: var(--disp); font-size: 1.06rem; }
.plain span { font-size: var(--f-sm); }
.trio { display: grid; gap: 1px; margin-top: 1.8rem; background: var(--line); border: 1px solid var(--line); }
@media (min-width: 820px) { .trio { grid-template-columns: repeat(3, 1fr); } }
.trio > div { padding: 1.3rem 1.4rem; background: var(--panel); }
.trio h3 { font-size: 1.1rem; }
.trio p { font-size: var(--f-sm); }
.figwide img, .figwide .img-placeholder { display: block; width: 100%; aspect-ratio: 21 / 9; object-fit: cover; }
.map { display: block; width: 100%; height: clamp(300px, 34vw, 380px); background: var(--panel-2); filter: grayscale(1) contrast(1.05) brightness(0.85); }
.where { display: grid; gap: 2rem; align-items: center; }
@media (min-width: 880px) { .where { grid-template-columns: 1fr 1fr; gap: 3rem; } }

/* 10 Pressure (signature) */
.pr { display: grid; gap: 1.8rem; }
@media (min-width: 980px) { .pr { grid-template-columns: 1fr 1fr; gap: 2.6rem; align-items: start; } .pr__set { position: sticky; top: 6rem; } }
.pr__set { padding: clamp(1.2rem, 1rem + 1.2vw, 1.8rem); background: var(--panel); border-top: 4px solid var(--lime); }
.pr__set fieldset { margin: 0; padding: 0; border: 0; }
.pr__set legend { display: block; margin-bottom: 0.8rem; padding: 0; font-family: var(--disp); font-weight: 700; font-size: 1.1rem; color: var(--ink); }
.symp { display: grid; gap: 0.4rem; }
.symp label { position: relative; }
.symp input { position: absolute; opacity: 0; }
.symp span { display: block; padding: 0.6rem 0.8rem; border: 1px solid var(--line); background: var(--bg); font-size: var(--f-sm); font-weight: 600; color: var(--text); cursor: pointer; }
.symp input:checked + span { background: var(--lime); border-color: var(--lime); color: var(--lime-ink); }
.symp input:focus-visible + span { outline: 3px solid var(--focus); outline-offset: 2px; }
.pr__out { padding: clamp(1.2rem, 1rem + 1.2vw, 1.8rem); background: var(--panel); border-top: 4px solid #5a5a5a; }
.pr__out h2 { font-size: 1.06rem; }
.pr__title { display: block; margin: 0.5rem 0 0.7rem; font-family: var(--disp); font-size: clamp(1.45rem, 1.2rem + 1.2vw, 2.1rem); font-weight: 700; color: var(--lime); line-height: 1.14; }
.pr__out ul { margin: 0.8rem 0 0; padding-left: 1.15em; font-size: var(--f-sm); }
.pr__out li { margin-bottom: 0.42rem; }
.pr__alarm { margin-top: 1.2rem; padding: 1rem 1.15rem; background: #3a1010; border-left: 4px solid #ff8a80; font-size: var(--f-sm); }
.pr__alarm b { display: block; margin-bottom: 0.25rem; color: #ffb3ad; }
.pr__out .caveat { margin-top: 1.2rem; padding-top: 0.9rem; border-top: 1px solid var(--line); font-size: 0.85rem; color: var(--muted); }

/* 11 FAQ */
.faq { display: grid; gap: 0; max-width: 880px; margin-top: 1.4rem; border-top: 2px solid var(--lime); }
.boq { border-bottom: 1px solid var(--line); }
.boq summary { display: flex; justify-content: space-between; gap: 1rem; padding: 1rem 0; font-family: var(--disp); font-weight: 700; font-size: 1.03rem; color: var(--ink); list-style: none; cursor: pointer; }
.boq summary::after { content: "+"; flex: none; color: var(--lime); }
.boq[open] summary::after { content: "\2013"; }
.boq > div { padding: 0 0 1.1rem; }

/* 12 Form & contact */
.form { display: grid; gap: 1rem 1.3rem; margin-top: 1.2rem; }
@media (min-width: 640px) { .form--2col { grid-template-columns: 1fr 1fr; } }
.field--full, .form__end { grid-column: 1 / -1; }
.field label, .picks legend { font-weight: 700; color: var(--ink); font-size: 0.94rem; }
.req { color: var(--err); }
.opt { font-weight: 400; color: var(--muted); }
input[type="text"], input[type="tel"], input[type="email"], input[type="number"], select, textarea { width: 100%; padding: 0.72rem 0.9rem; font: inherit; color: var(--ink); background: var(--bg); border: 1px solid #4a4a4a; border-radius: var(--r); }
select { appearance: none; background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23a3e635' stroke-width='2.6'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E"); background-repeat: no-repeat; background-position: right 0.85rem center; background-size: 15px; padding-right: 2.3rem; }
textarea { min-height: 140px; resize: vertical; }
input:focus, select:focus, textarea:focus { border-color: var(--lime); }
input::placeholder, textarea::placeholder { color: #7a7a74; }
.picks { margin: 0; padding: 0; border: 0; display: flex; flex-direction: row; flex-wrap: wrap; gap: 0.4rem; }
.picks legend { margin-bottom: 0.45rem; padding: 0; }
.pick { position: relative; }
.pick input { position: absolute; opacity: 0; }
.pick span { display: inline-block; padding: 0.44rem 0.9rem; border: 1px solid #4a4a4a; border-radius: var(--r); background: var(--bg); font-size: var(--f-sm); cursor: pointer; }
.pick input:checked + span { background: var(--lime); border-color: var(--lime); color: var(--lime-ink); }
.pick input:focus-visible + span { outline: 3px solid var(--focus); outline-offset: 2px; }
.form-note { margin: 0.5rem 0 0; font-size: 0.84rem; color: var(--muted); }
.contact { display: grid; gap: 2.2rem; align-items: start; }
@media (min-width: 920px) { .contact { grid-template-columns: 1.1fr 0.9fr; gap: 3rem; } }
.contact > * { min-width: 0; }
.side { display: grid; gap: 1rem; }
.side__card { padding: 1.2rem 1.35rem; background: var(--panel); border-left: 4px solid var(--lime); }
.side__card h2 { font-size: 1.04rem; }
.side__card .big { display: block; margin: 0.15rem 0 0.3rem; font-family: var(--disp); font-size: 1.45rem; font-weight: 700; color: var(--ink); text-decoration: none; }

/* 13 Footer */
.ft { background: #0d0d0d; color: var(--muted); font-size: var(--f-sm); border-top: 1px solid var(--line); }
.ft a { color: var(--ink); }
.ft__row { display: grid; gap: 1.5rem; padding-block: 2.8rem 1.6rem; }
@media (min-width: 820px) { .ft__row { grid-template-columns: 1.5fr 1fr 1fr; } }
.ft__name { margin: 0 0 0.45rem; font-family: var(--disp); font-size: 1.14rem; font-weight: 700; color: var(--ink); }
.ft h2 { margin: 0 0 0.55rem; font-family: var(--sans); font-size: 0.72rem; letter-spacing: 0.16em; text-transform: uppercase; color: var(--lime); }
.ft ul { margin: 0; padding: 0; list-style: none; display: grid; gap: 0.32rem; }
.ft__base { padding-block: 0.9rem; border-top: 1px solid var(--line); font-size: 0.8rem; }

/* 14 Images */
.img-placeholder { background: var(--panel-2); border: 1px dashed #4a4a4a; color: var(--muted); }
.img-placeholder b { color: var(--ink); overflow-wrap: anywhere; }