/* 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; } }

/* ==========================================================================
   SpectrumRise HVAC Studio — spectrumhvac.xyz
   Clean white page, ink type, a five-colour spectrum used as the accent.
   Split navigation around a centred logo.
   01 Tokens · 02 Base · 03 Header · 04 Hero & triptych · 05 Page heads
   06 Buttons · 07 Bands & blocks · 08 MERV scale (signature) · 09 FAQ table
   10 Form & contact · 11 Footer · 12 Images
   ========================================================================== */

/* 01 Tokens */
:root {
  --ink: #1e1b2e; --text: #3f3c4f; --muted: #636075; --line: #e6e4ee;
  --white: #ffffff; --paper: #faf9fc; --mist: #f1eff7;
  --s1: #e4572e; --s2: #f3a712; --s3: #29a36a; --s4: #2f7fd1; --s5: #7048c4;
  --btn: #1e1b2e; --btn-hover: #3b3654; --link: #5a3aa8;
  --focus: #5a3aa8; --err: #b42318; --ok: #1f6f3a;
  --font: "Sen", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --f-sm: 0.94rem; --f0: clamp(1rem, 0.97rem + 0.15vw, 1.08rem); --f1: clamp(1.2rem, 1.1rem + 0.45vw, 1.45rem);
  --f2: clamp(1.8rem, 1.45rem + 1.6vw, 2.7rem); --f3: clamp(2.4rem, 1.7rem + 3.4vw, 4.6rem);
  --wrap: 1180px; --pad-y: clamp(3.4rem, 2.4rem + 4vw, 6rem);
  --spectrum: linear-gradient(90deg, var(--s1) 0 20%, var(--s2) 20% 40%, var(--s3) 40% 60%, var(--s4) 60% 80%, var(--s5) 80% 100%);
}

/* 02 Base */
body { background: var(--white); color: var(--text); font-family: var(--font); font-size: var(--f0); line-height: 1.7; }
h1, h2, h3 { margin: 0 0 0.45em; font-weight: 700; color: var(--ink); line-height: 1.1; letter-spacing: -0.02em; text-wrap: balance; }
h1 { font-size: var(--f3); font-weight: 800; }
h2 { font-size: var(--f2); }
h3 { font-size: var(--f1); line-height: 1.22; }
p { margin: 0 0 1em; max-width: 62ch; }
p:last-child { margin-bottom: 0; }
a { color: var(--link); text-underline-offset: 3px; }
a:hover { color: var(--ink); }
strong, b { color: var(--ink); }
ul, ol { margin: 0 0 1em; padding-left: 1.2em; }
.wrap { width: min(100% - 2rem, var(--wrap)); margin-inline: auto; }
.stripe { display: block; width: 72px; height: 6px; margin-bottom: 1.1rem; border-radius: 3px; background: var(--spectrum); }
.center { text-align: center; }
.center p, .center .stripe { margin-inline: auto; }

/* 03 Header */
.hdr { position: sticky; top: 0; z-index: 90; background: rgba(255,255,255,0.97); border-bottom: 1px solid var(--line); }
.hdr__row { display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 1rem; min-height: 78px; }
.hdr__left, .hdr__right { display: flex; align-items: center; gap: 0.3rem; }
.hdr__right { justify-content: flex-end; }
.logo { display: flex; flex-direction: column; align-items: center; color: var(--ink); text-decoration: none; line-height: 1; }
.logo svg { width: 64px; height: 12px; margin-bottom: 0.35rem; }
.logo b { font-size: 1.45rem; font-weight: 800; letter-spacing: -0.02em; }
.logo small { margin-top: 0.25rem; font-size: 0.66rem; letter-spacing: 0.26em; text-transform: uppercase; color: var(--muted); }
.navlink { position: relative; padding: 0.5rem 0.85rem; color: var(--ink); text-decoration: none; font-weight: 700; font-size: 0.98rem; white-space: nowrap; }
.navlink:hover { color: var(--link); }
.navlink[aria-current="page"]::after { content: ""; position: absolute; left: 0.85rem; right: 0.85rem; bottom: 0.1rem; height: 4px; border-radius: 2px; background: var(--spectrum); }
.hdr__tel { display: inline-flex; align-items: center; gap: 0.4rem; margin-right: 0.6rem; color: var(--ink); font-weight: 700; text-decoration: none; white-space: nowrap; }
.hdr__tel svg { width: 16px; height: 16px; color: var(--s4); }
.mnav, .nav-toggle { display: none; }
@media (max-width: 1099px) {
  .hdr__row { grid-template-columns: auto 1fr; }
  .hdr__row > .logo { grid-row: 1; grid-column: 1; align-items: flex-start; }
  .hdr__left, .hdr__right .navlink, .hdr__right .btn { display: none; }
  .hdr__right { grid-column: 2; }
  .hdr__tel span { display: none; }
  .hdr__tel { width: 44px; height: 44px; justify-content: center; margin: 0; border: 1px solid var(--line); border-radius: 50%; }
  .nav-toggle { display: inline-flex; align-items: center; justify-content: center; width: 44px; height: 44px; padding: 0; border: 0; border-radius: 50%; background: var(--mist); color: var(--ink); cursor: pointer; }
  .nav-toggle svg { width: 22px; height: 22px; }
  .mnav { position: absolute; left: 0; right: 0; top: 100%; flex-direction: column; padding: 0.6rem 1rem 1.2rem; background: var(--white); border-bottom: 1px solid var(--line); }
  .mnav.is-open { display: flex; }
  .mnav .navlink { padding: 0.9rem 0.2rem; border-bottom: 1px solid var(--line); font-size: 1.08rem; }
  .mnav .navlink[aria-current="page"]::after { left: auto; right: 0.2rem; top: 50%; width: 40px; transform: translateY(-50%); }
}
@media (max-width: 420px) { .logo b { font-size: 1.25rem; } .logo small { letter-spacing: 0.14em; } .hdr__right { gap: 0.4rem; } }

/* 04 Hero & triptych */
.hero { padding-block: clamp(3rem, 2rem + 4vw, 5.5rem) clamp(2rem, 1.5rem + 2vw, 3rem); text-align: center; }
.hero h1 { max-width: 16ch; margin-inline: auto; }
.hero p { margin-inline: auto; font-size: var(--f1); line-height: 1.5; max-width: 44ch; }
.hero .btns { justify-content: center; margin-top: 1.8rem; }
.hero .stripe { margin-inline: auto; width: 120px; }
.trip { display: grid; gap: 10px; grid-template-columns: 1fr; }
@media (min-width: 760px) { .trip { grid-template-columns: 1fr 1.4fr 1fr; } }
.trip figure img, .trip figure .img-placeholder { width: 100%; height: clamp(220px, 34vw, 440px); object-fit: cover; border-radius: 0; }
.trip figure { position: relative; }
.trip figure::after { content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 6px; background: var(--c, var(--s4)); }
.trip figure:nth-child(1) { --c: var(--s1); } .trip figure:nth-child(2) { --c: var(--s3); } .trip figure:nth-child(3) { --c: var(--s5); }
@media (max-width: 759px) { .trip figure:not(:first-child) { display: none; } }

/* 05 Page heads */
.phead { padding-block: clamp(2.8rem, 2rem + 3vw, 4.6rem) clamp(2rem, 1.5rem + 2vw, 3rem); text-align: center; background: var(--paper); border-bottom: 1px solid var(--line); }
.phead h1 { max-width: 20ch; margin-inline: auto; font-size: clamp(2.1rem, 1.6rem + 2.4vw, 3.5rem); }
.phead p { margin-inline: auto; font-size: var(--f1); line-height: 1.5; max-width: 50ch; }
.phead .stripe { margin-inline: auto; }
.crumbs { display: flex; justify-content: center; gap: 0.5rem; margin: 0 0 1rem; padding: 0; list-style: none; font-size: var(--f-sm); color: var(--muted); }
.crumbs li + li::before { content: "·"; margin-right: 0.5rem; }

/* 06 Buttons */
.btns { display: flex; flex-wrap: wrap; gap: 0.7rem; }
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 0.5rem; padding: 0.8rem 1.45rem; border: 2px solid transparent; border-radius: 10px; font: inherit; font-weight: 700; text-decoration: none; white-space: nowrap; cursor: pointer; transition: background-color 0.2s, color 0.2s; }
.btn svg { width: 1em; height: 1em; }
.btn--ink { background: var(--btn); color: #fff; }
.btn--ink:hover { background: var(--btn-hover); color: #fff; }
.btn--line { border-color: var(--ink); color: var(--ink); }
.btn--line:hover { background: var(--ink); color: #fff; }
.btn--white { background: #fff; color: var(--ink); }
.btn--white:hover { background: var(--mist); color: var(--ink); }

/* 07 Bands & blocks */
.sec { padding-block: var(--pad-y); }
.sec--paper { background: var(--paper); }
.sec--ink { background: var(--ink); color: #cfcbe0; }
.sec--ink h2, .sec--ink h3 { color: #fff; }
.sec--ink a { color: #fff; }
.sec--ink :focus-visible { outline-color: #fff; }
.band { display: grid; gap: 0; grid-template-columns: 1fr; border: 1px solid var(--line); border-radius: 16px; overflow: hidden; }
@media (min-width: 900px) { .band { grid-template-columns: repeat(5, 1fr); } }
.band > a { display: flex; flex-direction: column; gap: 0.4rem; padding: 1.6rem 1.3rem; color: var(--text); text-decoration: none; border-top: 6px solid var(--c); background: var(--white); }
.band > a + a { border-left: 1px solid var(--line); }
@media (max-width: 899px) { .band > a + a { border-left: 0; } }
.band > a:nth-child(1) { --c: var(--s1); } .band > a:nth-child(2) { --c: var(--s2); } .band > a:nth-child(3) { --c: var(--s3); } .band > a:nth-child(4) { --c: var(--s4); } .band > a:nth-child(5) { --c: var(--s5); }
.band > a:hover { background: var(--paper); }
.band h3 { margin: 0; font-size: 1.15rem; }
.band p { margin: 0; font-size: var(--f-sm); }
.pair { display: grid; gap: 2rem; }
@media (min-width: 860px) { .pair { grid-template-columns: 1fr 1fr; gap: 4rem; } }
.pair > * { min-width: 0; }
.pair h2 { font-size: clamp(1.6rem, 1.35rem + 1vw, 2.2rem); }
.pair .ic { width: 48px; height: 48px; margin-bottom: 1rem; color: var(--s4); }
.pair > :last-child .ic { color: var(--s5); }
.dash { margin: 1rem 0 1.4rem; padding: 0; list-style: none; }
.dash li { padding: 0.55rem 0; border-bottom: 1px dashed var(--line); }
.teaser { display: grid; gap: 2rem; align-items: center; padding: clamp(1.5rem, 1rem + 2vw, 2.8rem); border-radius: 20px; background: var(--ink); color: #cfcbe0; }
@media (min-width: 900px) { .teaser { grid-template-columns: 1fr 1fr; } }
.teaser h2 { color: #fff; }
.teaser :focus-visible { outline-color: #fff; }
.mini-scale { display: grid; grid-template-columns: repeat(16, 1fr); gap: 3px; }
.mini-scale span { height: 44px; border-radius: 3px; background: hsl(calc(10 + var(--i) * 17) 70% 55%); }
.mini-labels { display: flex; justify-content: space-between; margin-top: 0.5rem; font-size: var(--f-sm); color: #cfcbe0; }
.map-plain { width: 100%; aspect-ratio: 16 / 9; min-height: 280px; border-radius: 16px; background: var(--mist); }

/* 08 MERV scale (signature) */
.merv { display: grid; grid-template-columns: repeat(16, 1fr); gap: 4px; }
.merv__cell { display: grid; place-items: center; height: 70px; border-radius: 6px; background: hsl(calc(10 + var(--i) * 17) 70% 52%); color: #fff; font-weight: 800; font-size: 0.95rem; }
.merv__cell.is-dim { opacity: 0.3; }
@media (max-width: 640px) { .merv__cell { height: 48px; font-size: 0.7rem; } }
.ranges { display: grid; gap: 1rem; margin-top: 1.4rem; }
@media (min-width: 860px) { .ranges { grid-template-columns: repeat(4, 1fr); } }
.range { padding: 1.3rem; border: 2px solid var(--line); border-radius: 14px; background: var(--white); }
.range h3 { font-size: 1.15rem; }
.range .tagline { display: inline-block; margin-bottom: 0.5rem; padding: 0.15rem 0.6rem; border-radius: 999px; background: var(--mist); font-size: 0.82rem; font-weight: 700; color: var(--ink); }
.range p { font-size: var(--f-sm); }
.range.is-on { border-color: var(--ink); box-shadow: 0 10px 30px -18px rgba(30,27,46,0.5); }
.pickers { display: none; flex-wrap: wrap; gap: 0.5rem; margin-top: 1.2rem; }
.is-live .pickers { display: flex; }
.pickers button { padding: 0.6rem 1rem; border: 2px solid var(--ink); border-radius: 999px; background: var(--white); color: var(--ink); font: inherit; font-weight: 700; cursor: pointer; }
.pickers button[aria-pressed="true"] { background: var(--ink); color: #fff; }
.checklist { margin: 0; padding: 0; list-style: none; display: grid; gap: 0.7rem; }
.checklist li { display: grid; grid-template-columns: 1.6rem 1fr; gap: 0.6rem; }
.checklist li::before { content: ""; width: 1.2rem; height: 1.2rem; margin-top: 0.3rem; border-radius: 50%; background: var(--spectrum); }

/* 09 FAQ table */
.faq-table { border-top: 2px solid var(--ink); }
.qrow { display: grid; gap: 0.4rem 3rem; padding: 1.4rem 0; border-bottom: 1px solid var(--line); }
@media (min-width: 860px) { .qrow { grid-template-columns: 0.9fr 1.1fr; } }
.qrow h3 { margin: 0; font-size: 1.12rem; }
.qrow p { margin: 0; font-size: var(--f-sm); }

/* 10 Form & contact */
.form { display: grid; gap: 1rem 1.2rem; margin-top: 1.4rem; }
@media (min-width: 680px) { .form--2col { grid-template-columns: 1fr 1fr; } }
.field--full, .form__end { grid-column: 1 / -1; }
.field label { font-weight: 700; font-size: var(--f-sm); color: var(--ink); }
.req { color: var(--s1); }
.opt { font-weight: 400; color: var(--muted); }
input[type="text"], input[type="tel"], input[type="email"], select, textarea { width: 100%; padding: 0.8rem 0.95rem; font: inherit; color: var(--ink); background: var(--paper); border: 1.5px solid #cfcbdc; border-radius: 10px; }
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='%231e1b2e' stroke-width='2.5'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E"); background-repeat: no-repeat; background-position: right 0.9rem center; background-size: 15px; padding-right: 2.4rem; }
textarea { min-height: 130px; resize: vertical; }
input:focus, select:focus, textarea:focus { border-color: var(--s5); background: var(--white); }
.form-status { margin: 0.8rem 0 0; }
.form-note { margin: 0.5rem 0 0; font-size: 0.85rem; color: var(--muted); }
.contact-split { display: grid; gap: 2rem; }
@media (min-width: 960px) { .contact-split { grid-template-columns: 0.9fr 1.1fr; align-items: start; } }
.contact-split > * { min-width: 0; }
.lines { margin: 1.4rem 0 0; }
.lines div { padding: 1rem 0; border-bottom: 1px solid rgba(255,255,255,0.15); }
.lines dt { font-size: 0.78rem; letter-spacing: 0.16em; text-transform: uppercase; color: #a9a4c2; }
.lines dd { margin: 0.2rem 0 0; color: #fff; }
.lines .big { font-size: 1.8rem; font-weight: 800; color: #fff; text-decoration: none; }
.card { padding: clamp(1.4rem, 1rem + 2vw, 2.4rem); background: var(--white); border-radius: 18px; color: var(--text); }
.card h2 { color: var(--ink); }
.card :focus-visible { outline-color: var(--focus); }

/* 11 Footer */
.ftr { position: relative; background: var(--ink); color: #a9a4c2; font-size: var(--f-sm); }
.ftr::before { content: ""; display: block; height: 6px; background: var(--spectrum); }
.ftr__grid { display: grid; gap: 1.8rem; padding-block: 2.8rem 1.6rem; }
@media (min-width: 820px) { .ftr__grid { grid-template-columns: 1.4fr 1fr 1fr; } }
.ftr h2 { margin-bottom: 0.7rem; font-size: 1rem; color: #fff; }
.ftr ul { margin: 0; padding: 0; list-style: none; display: grid; gap: 0.35rem; }
.ftr a { color: #fff; text-decoration: none; }
.ftr a:hover { text-decoration: underline; }
.ftr :focus-visible { outline-color: #fff; }
.ftr__base { padding-block: 1rem; border-top: 1px solid #34304a; font-size: 0.82rem; }
.ftr__base p { margin: 0; max-width: none; }

/* 12 Images */
.img-placeholder { background: var(--mist); border: 1px dashed #c6c1d8; color: var(--muted); }
.img-placeholder b { color: var(--ink); }
figure img, figure .img-placeholder { border-radius: 16px; }
figcaption { margin-top: 0.5rem; font-size: 0.86rem; color: var(--muted); }
.mt { margin-top: 2rem; }
.mini-scale span:nth-child(1), .merv__cell:nth-child(1) { --i: 0; }
.mini-scale span:nth-child(2), .merv__cell:nth-child(2) { --i: 1; }
.mini-scale span:nth-child(3), .merv__cell:nth-child(3) { --i: 2; }
.mini-scale span:nth-child(4), .merv__cell:nth-child(4) { --i: 3; }
.mini-scale span:nth-child(5), .merv__cell:nth-child(5) { --i: 4; }
.mini-scale span:nth-child(6), .merv__cell:nth-child(6) { --i: 5; }
.mini-scale span:nth-child(7), .merv__cell:nth-child(7) { --i: 6; }
.mini-scale span:nth-child(8), .merv__cell:nth-child(8) { --i: 7; }
.mini-scale span:nth-child(9), .merv__cell:nth-child(9) { --i: 8; }
.mini-scale span:nth-child(10), .merv__cell:nth-child(10) { --i: 9; }
.mini-scale span:nth-child(11), .merv__cell:nth-child(11) { --i: 10; }
.mini-scale span:nth-child(12), .merv__cell:nth-child(12) { --i: 11; }
.mini-scale span:nth-child(13), .merv__cell:nth-child(13) { --i: 12; }
.mini-scale span:nth-child(14), .merv__cell:nth-child(14) { --i: 13; }
.mini-scale span:nth-child(15), .merv__cell:nth-child(15) { --i: 14; }
.mini-scale span:nth-child(16), .merv__cell:nth-child(16) { --i: 15; }
.btns--c { justify-content: center; margin-top: 1.4rem; }
.crumbs--left { justify-content: flex-start; color: #a9a4c2; }
.sec--ink h1 { color: #fff; font-size: clamp(2.2rem, 1.7rem + 2.4vw, 3.6rem); }
.h3like { margin: 0; font-size: 1.12rem; }
.sec--ink .card a { color: var(--link); }
.hdr__right .hdr__tel--m { display: none; }
@media (max-width: 1099px) { .hdr__right .hdr__tel--m { display: inline-flex; } }