/* ============================================================
   BLUEPRINT TRADE — technical-craft design system
   Trade: ventilation / energy-tech. Precise, measured, industrial.
   ============================================================
   PALETTE: blueprint-white + steel blue accent + mono annotations.
   Max 3 colors. Valve-line / blueprint-grid texture, JetBrains Mono
   for code-like labels, Space Grotesk for display. Cold & precise.
   ============================================================ */

:root {
  color-scheme: light;

  --paper: #f7f9fb;        /* blueprint white */
  --paper-soft: #eef2f6;
  --ink: #0f2530;          /* deep steel */
  --ink-soft: #4b6572;

  --line: #d5dee6;
  --line-strong: #b0c0cd;

  /* fixed dark surfaces */
  --steel: #0e1b24;        /* deep steel-charcoal */
  --steel-soft: #16252f;
  --steel-line: #27404e;

  /* accent — steel blue */
  --accent: #2a6f97;
  --accent-ink: #f4fafd;
  --accent-soft: #dbeaf2;
  --accent-strong: #1f5c82;

  /* mono for annotations */
  --font-mono: 'JetBrains Mono', 'SFMono-Regular', Consolas, monospace;
  --font-display: 'Space Grotesk', system-ui, sans-serif;
  --font-body: 'Inter', system-ui, sans-serif;

  --space-section: clamp(4.5rem, 10vw, 7.5rem);
  --radius: 0px;
}

html[data-theme='dark'] {
  color-scheme: dark;
  --paper: #0d151c;
  --paper-soft: #141f28;
  --ink: #dce8ee;
  --ink-soft: #8ba4b2;
  --line: #25343f;
  --line-strong: #35505e;
  --accent: #4d9bc2;
  --accent-strong: #6db2d6;
}

*,
*::before,
*::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-body);
  line-height: 1.75;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--ink);
  text-wrap: balance;
}
a { color: var(--accent-strong); }
a:hover { color: var(--accent); }
.container { width: min(1120px, 92%); margin-inline: auto; }
section { padding-block: var(--space-section); }

/* blueprint grid texture */
.blueprint-grid {
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 28px 28px;
}

/* mono label */
.mono {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  color: var(--accent-strong);
  text-transform: uppercase;
}

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 48px; padding: 0.75rem 1.6rem;
  border-radius: var(--radius);
  font-family: var(--font-body); font-weight: 600; font-size: 1rem; text-decoration: none;
  border: 1px solid transparent; cursor: pointer;
  transition: background 150ms ease, color 150ms ease;
  touch-action: manipulation;
}
.btn--primary { background: var(--accent); color: var(--accent-ink); }
.btn--primary:hover { background: var(--accent-strong); color: var(--accent-ink); }
.btn--ghost { border: 1px solid var(--line-strong); color: var(--ink); }
.btn--ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* header */
.header { position: sticky; top: 0; z-index: 50; background: var(--steel); color: #fff; border-bottom: 1px solid var(--steel-line); min-height: 64px; }
.header__inner { display: flex; align-items: center; justify-content: space-between; gap: 1.5rem; min-height: 64px; flex-wrap: nowrap; }
.header__brand { font-family: var(--font-display); font-weight: 600; font-size: 1.25rem; color: #fff; text-decoration: none; letter-spacing: -0.02em; white-space: nowrap; }
.header__brand:hover { color: var(--accent); }
.header__nav { display: flex; align-items: center; gap: 2rem; }
.header__nav a { color: #bcd0da; text-decoration: none; font-size: 0.93rem; }
.header__nav a:hover { color: #fff; }
.header__phone { display: flex; align-items: center; gap: 0.4rem; color: #fff; text-decoration: none; font-weight: 600; white-space: nowrap; font-size: 0.93rem; }
.header__phone:hover { color: var(--accent); }
@media (max-width: 640px) { .header__nav { display: none; } }
@media (max-width: 479px) {
  .header__phone .header__phone-label { display: none; }
  .header__phone .header__phone-num { display: none; }
}

/* hero — blueprint grid, mono annotations, split */
.hero {
  background: var(--paper);
  position: relative;
  padding-block: clamp(4rem, 9vw, 6rem);
}
.hero__inner { display: grid; grid-template-columns: 1.2fr 0.8fr; gap: 3rem; align-items: center; }
.hero__content { position: relative; }
.hero__kicker {
  font-family: var(--font-mono);
  font-size: 0.8rem; letter-spacing: 0.1em;
  color: var(--accent-strong);
  background: transparent;
  border: 1px dashed var(--accent);
  display: inline-block; padding: 0.35rem 0.8rem;
  margin-bottom: 1.5rem;
}
.hero__title { font-size: clamp(2.2rem, 5.5vw, 3.8rem); margin-bottom: 1.25rem; max-width: 16ch; }
.hero__sub { font-size: 1.1rem; color: var(--ink-soft); max-width: 46ch; margin-bottom: 2rem; }
.hero__cta { display: flex; gap: 0.75rem; flex-wrap: wrap; }
.hero__diagram {
  background: var(--steel);
  color: #dce8ee;
  padding: 2rem;
  position: relative;
  border-left: 4px solid var(--accent);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 2;
}
.hero__diagram::before {
  content: '';
  position: absolute; inset: 0;
  background-image:
    linear-gradient(var(--steel-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--steel-line) 1px, transparent 1px);
  background-size: 20px 20px;
  opacity: 0.5;
}
.hero__diagram .diagram-line {
  position: relative;
  display: flex; justify-content: space-between;
  border-bottom: 1px dashed var(--steel-line);
  padding: 0.3rem 0;
}
.hero__diagram .tag { color: #4d9bc2; }
/* labels on always-dark sections need the lighter steel (strong is too dark) */
.band .section__label {
  color: #4d9bc2;
}

/* section labels */
.section__label {
  font-family: var(--font-mono);
  font-size: 0.76rem; letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--accent-strong);
  margin-bottom: 0.75rem;
}
.section__title { font-size: clamp(1.9rem, 4.5vw, 2.9rem); margin-bottom: 1rem; max-width: 20ch; }
.section__lede { color: var(--ink-soft); max-width: 52ch; }

/* services — technical rows with mono codes */
.services__list { margin-top: 2.5rem; display: grid; gap: 0; }
.service {
  display: grid;
  grid-template-columns: 4rem 1fr;
  gap: 1.75rem;
  align-items: start;
  padding: 1.75rem 0;
  border-bottom: 1px solid var(--line);
}
.service:first-child { border-top: 1px solid var(--line); }
.service__code {
  font-family: var(--font-mono);
  font-size: 0.9rem; color: var(--accent-strong);
  padding-top: 0.2rem;
}
.service h3 { font-size: 1.5rem; margin-bottom: 0.5rem; }
.service p { color: var(--ink-soft); }

/* credentials — steel band */
.band { background: var(--steel); color: #fff; }
.band__inner { display: grid; grid-template-columns: 1fr 1fr; gap: 3rem; align-items: center; }
.band h2 { color: #fff; }
.band p { color: #bcd0da; }
.band__creds { list-style: none; display: grid; gap: 0.85rem; }
.band__creds li {
  display: flex; align-items: center; gap: 0.75rem;
  color: #dce8ee; font-family: var(--font-mono); font-size: 0.9rem;
}
.band__creds li::before { content: '▸'; color: var(--accent); flex-shrink: 0; }

/* about */
.about__inner { max-width: 60ch; }
.about__body { color: var(--ink-soft); font-size: 1.1rem; }
.about__quote {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--accent);
  margin-top: 1.5rem;
  border-left: 3px solid var(--accent);
  padding-left: 1rem;
}

/* contact */
.contact__grid { display: grid; grid-template-columns: 1fr 1fr; gap: 3.5rem; align-items: start; }
.contact__form { display: grid; gap: 1rem; }
.contact__form label { font-size: 0.9rem; color: var(--ink-soft); }
.contact__form input, .contact__form textarea {
  width: 100%; padding: 0.8rem 1rem;
  background: var(--paper-soft); border: 1px solid var(--line); border-radius: var(--radius);
  color: var(--ink); font-family: var(--font-body); font-size: 1rem;
}
.contact__form input:focus, .contact__form textarea:focus { outline: 2px solid var(--accent); outline-offset: 1px; border-color: var(--accent); }
.contact__info { display: grid; gap: 0; background: var(--paper-soft); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.5rem; }
.contact__info-head {
  display: flex; align-items: center; gap: 0.5rem;
  color: var(--accent-strong);
  font-size: 0.78rem; font-weight: 600; letter-spacing: 0.14em; text-transform: uppercase;
  margin-bottom: 0.5rem;
}
.contact__info-item { padding: 1rem 0; border-bottom: 1px solid var(--line); }
.contact__info-item:first-of-type { padding-top: 0; }
.contact__info-item:last-child { padding-bottom: 0; border-bottom: none; }
.contact__info-item strong { display: block; color: var(--ink); margin-bottom: 0.2rem; }
.contact__info-item span, .contact__info-item a { color: var(--ink-soft); }
.contact__info-item a:hover { color: var(--accent-strong); }
.contact__info-cta { margin-top: 1.5rem; }
.contact__info-cta .btn--primary { width: 100%; }

/* footer */
.footer { background: var(--steel); color: #9fb4c0; border-top: 1px solid var(--steel-line); padding-block: 2rem; }
.footer__bottom { display: flex; align-items: center; justify-content: space-between; gap: 1rem; flex-wrap: wrap; padding-top: 1.5rem; border-top: 1px solid var(--steel-line); }
.footer__copy { font-size: 0.85rem; }

/* theme switch */
.theme-switch { display: inline-flex; align-items: center; gap: 0.6rem; font-size: 0.85rem; color: #bcd0da; }
.theme-switch button[role='switch'] {
  width: 52px; height: 28px; border-radius: 999px;
  border: 1px solid var(--steel-line); background: var(--steel-soft);
  cursor: pointer; position: relative; padding: 0;
  transition: background 150ms ease; touch-action: manipulation;
}
.theme-switch button[role='switch']::before {
  content: ''; position: absolute; top: 3px; left: 3px;
  width: 20px; height: 20px; border-radius: 50%;
  background: #fff; transition: transform 200ms ease;
}
.theme-switch button[role='switch'][aria-checked='true']::before { transform: translateX(24px); background: var(--accent); }
.theme-switch button[role='switch'][aria-checked='true'] { background: rgba(42,111,151,0.3); }
.theme-switch button[role='switch']:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

@media (max-width: 860px) {
  .hero__inner, .band__inner, .contact__grid { grid-template-columns: 1fr; gap: 1.5rem; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}