:root {
  --paper: #ecebe7;
  --paper-2: #e2e0da;
  --card: #f5f4f1;
  --ink: #141414;
  --muted: #5f5c56;
  --line: #c9c5bc;
  --accent: #ff4d00;
  --accent-ink: #ffffff;
  --dark: #151515;
  --dark-2: #1f1f1e;
  --dark-line: #34332f;
  --dark-muted: #a19e97;

  --f-display: "Inter Tight", "Helvetica Neue", Arial, sans-serif;
  --f-body: "Golos Text", system-ui, -apple-system, "Segoe UI", sans-serif;
  --f-mono: "JetBrains Mono", ui-monospace, Menlo, monospace;

  --gutter: clamp(16px, 4vw, 40px);
  --rhythm: clamp(72px, 10vw, 136px);
  --maxw: 1240px;
  --r: 4px;
  color-scheme: light;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 17px/1.55 var(--f-body);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; }
h1, h2, h3 { font-family: var(--f-display); margin: 0; letter-spacing: -0.025em; }
p { margin: 0; }

.wrap { max-width: var(--maxw); margin-inline: auto; padding-inline: var(--gutter); }
.mono { font-family: var(--f-mono); font-size: 13px; letter-spacing: 0.02em; }
.muted { color: var(--muted); }
.dot { color: var(--accent); }
.eyebrow { font-family: var(--f-mono); font-size: 13px; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); margin-bottom: 20px; }
.lead { font-size: clamp(17px, 1.5vw, 20px); line-height: 1.5; color: var(--muted); max-width: 46ch; }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 52px; padding: 0 26px;
  font: 600 16px/1 var(--f-body); text-decoration: none;
  border-radius: var(--r); border: 1.5px solid transparent;
  cursor: pointer; transition: background .15s, color .15s, border-color .15s, transform .15s;
}
.btn:active { transform: translateY(1px); }
.btn--accent { background: var(--accent); color: var(--accent-ink); }
.btn--accent:hover { background: #e64500; }
.btn--ghost { border-color: var(--ink); color: var(--ink); }
.btn--ghost:hover { background: var(--ink); color: var(--paper); }
.btn--full { width: 100%; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

/* ---------- header ---------- */
.top {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.top__in { display: flex; align-items: center; gap: 32px; height: 64px; }
.logo { font: 800 20px/1 var(--f-display); letter-spacing: -0.03em; text-decoration: none; white-space: nowrap; }
.logo--sm { font-size: 17px; }
.nav { display: flex; gap: 28px; margin-left: auto; }
.nav a { text-decoration: none; font-size: 15px; font-weight: 500; }
.nav a:hover { color: var(--accent); }
.top__phone { font-family: var(--f-mono); font-size: 14px; font-weight: 500; text-decoration: none; white-space: nowrap; }
.burger { display: none; background: none; border: 0; width: 44px; height: 44px; padding: 12px 10px; cursor: pointer; margin-right: -10px; }
.burger span { display: block; height: 2px; background: var(--ink); transition: transform .2s; }
.burger span + span { margin-top: 8px; }
.burger[aria-expanded="true"] span:first-child { transform: translateY(5px) rotate(45deg); }
.burger[aria-expanded="true"] span:last-child { transform: translateY(-5px) rotate(-45deg); }

/* ---------- hero ---------- */
.hero { padding-block: clamp(40px, 7vh, 88px) clamp(48px, 8vh, 96px); }
.hero__grid { display: grid; grid-template-columns: 1.15fr 1fr; gap: clamp(24px, 4vw, 64px); align-items: center; }
.hero h1 {
  font-weight: 800;
  font-size: clamp(38px, 5.2vw, 76px);
  line-height: 0.98;
  letter-spacing: -0.04em;
  margin-bottom: 28px;
}
.hero__cta { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 36px; }
.hero__art { margin: 0; }
.hero__art figcaption { color: var(--muted); margin-top: 8px; text-align: right; }

.axo { width: 100%; height: auto; overflow: visible; }
.axo path { stroke: var(--ink); stroke-width: 1.4; stroke-linejoin: round; }
.axo-ground { fill: none; stroke: var(--line) !important; stroke-dasharray: 4 5; }
.axo-top { fill: var(--card); }
.axo-r { fill: #d6d3cc; }
.axo-l { fill: #bfbbb2; }
.axo-glass { fill: var(--ink); }
.axo-door { fill: #9a968d; }
.axo-dim path { fill: none; stroke: var(--muted); stroke-width: 1; }
.axo-dim text, .axo-point text { font: 500 12px var(--f-mono); fill: var(--muted); }
.axo-point circle { fill: var(--accent); stroke: none; }
.axo-point path { fill: none; stroke: var(--accent); stroke-width: 1.2; }
.axo-point text { fill: var(--ink); }

/* ---------- index ---------- */
.index { border-top: 1px solid var(--ink); }
.index__row {
  display: grid; grid-template-columns: 64px minmax(0, 1.1fr) minmax(0, 1fr) 40px; gap: 24px;
  align-items: baseline; padding: 28px 0;
  border-bottom: 1px solid var(--line); text-decoration: none;
  transition: padding .2s;
}
.index__t { font: 800 clamp(24px, 3vw, 40px)/1.05 var(--f-display); letter-spacing: -0.03em; }
.index__d { color: var(--muted); }
.index__arr { font-size: 24px; text-align: right; transition: transform .2s, color .2s; }
.index__row:hover .index__arr { transform: translateX(6px); color: var(--accent); }
.index__row:hover .index__t { color: var(--accent); }

/* ---------- sections ---------- */
.sec { padding-block: var(--rhythm); }
.sec--alt { background: var(--paper-2); }
.sec__head { margin-bottom: clamp(40px, 6vw, 72px); max-width: 900px; }
.sec__n { display: block; color: var(--muted); text-transform: uppercase; margin-bottom: 16px; }
.sec h2 { font-weight: 800; font-size: clamp(32px, 4.4vw, 60px); line-height: 1.02; letter-spacing: -0.035em; }
.sec__head .lead { margin-top: 24px; }
h3 { font-weight: 600; font-size: 22px; line-height: 1.2; letter-spacing: -0.02em; }

.cols3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: clamp(24px, 3vw, 48px); }
.feat { border-top: 2px solid var(--ink); padding-top: 20px; }
.feat h3 { margin-bottom: 10px; }
.feat p { color: var(--muted); }

.steps {
  list-style: none; margin: clamp(56px, 8vw, 96px) 0 0; padding: 0;
  display: grid; grid-template-columns: repeat(6, minmax(0, 1fr));
  border-top: 1px solid var(--line);
}
.steps li { padding: 20px 16px 0 0; display: flex; flex-direction: column; gap: 6px; position: relative; }
.steps li::before { content: ""; position: absolute; top: -5px; left: 0; width: 9px; height: 9px; border-radius: 50%; background: var(--ink); }
.steps li:first-child::before { background: var(--accent); }
.steps .mono { color: var(--muted); }
.steps b { font-weight: 600; font-size: 17px; }
.steps li > span:last-child { color: var(--muted); font-size: 15px; line-height: 1.45; }

/* ---------- calculator ---------- */
.calc {
  margin-top: clamp(56px, 8vw, 96px);
  display: grid; grid-template-columns: 1.2fr 1fr;
  background: var(--card); border: 1px solid var(--line); border-radius: var(--r);
}
.calc__form { padding: clamp(24px, 4vw, 48px); display: grid; gap: 26px; align-content: start; }
.calc__form h3 { font-size: clamp(26px, 2.6vw, 34px); font-weight: 800; }
.calc__form > p { margin-top: -16px; }
.calc__res {
  padding: clamp(24px, 4vw, 48px); background: var(--ink); color: var(--paper);
  display: flex; flex-direction: column; gap: 14px;
  border-radius: 0 var(--r) var(--r) 0;
}
.calc__res .muted { color: var(--dark-muted); }
.calc__sum { font: 800 clamp(36px, 4.2vw, 56px)/1 var(--f-display); letter-spacing: -0.035em; font-variant-numeric: tabular-nums; }
.calc__per { color: var(--dark-muted); }
.calc__bar { height: 6px; background: var(--dark-line); border-radius: 3px; overflow: hidden; }
.calc__bar span { display: block; height: 100%; width: 0; background: var(--accent); transition: width .3s; }
.calc__lines { list-style: none; padding: 0; margin: 4px 0 auto; display: grid; gap: 8px; color: var(--dark-muted); }
.calc__lines li { display: flex; justify-content: space-between; gap: 16px; border-bottom: 1px dashed var(--dark-line); padding-bottom: 8px; }
.calc__lines li span:last-child { color: var(--paper); }
.calc__res .btn { margin-top: 12px; }

.field { display: grid; gap: 10px; border: 0; padding: 0; margin: 0; min-width: 0; }
.field__l { font-weight: 500; font-size: 15px; display: flex; justify-content: space-between; gap: 12px; padding: 0; }
.field__l output { color: var(--accent); font-size: 15px; }
input[type="range"] { width: 100%; accent-color: var(--accent); height: 28px; }
.seg { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); border: 1.5px solid var(--ink); border-radius: var(--r); overflow: hidden; }
.seg--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.seg label { position: relative; cursor: pointer; }
.seg label + label { border-left: 1.5px solid var(--ink); }
.seg input { position: absolute; opacity: 0; inset: 0; cursor: pointer; }
.seg span { display: flex; align-items: center; justify-content: center; min-height: 46px; padding: 0 8px; font-size: 15px; font-weight: 500; text-align: center; line-height: 1.2; }
.seg input:checked + span { background: var(--ink); color: var(--paper); }
.seg input:focus-visible + span { outline: 2px solid var(--accent); outline-offset: -4px; }

.field__note { font-size: 14px; line-height: 1.45; margin-top: 2px; }
.unit--cta { background: var(--paper); }
.check { display: flex; gap: 12px; align-items: flex-start; cursor: pointer; font-weight: 500; }
.check input { width: 20px; height: 20px; margin: 2px 0 0; accent-color: var(--accent); flex: none; }
.check--sm { font-size: 14px; font-weight: 400; color: var(--muted); }

/* ---------- fleet ---------- */
.fleet { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1px; background: var(--line); border: 1px solid var(--line); }
.unit { background: var(--card); padding: 28px; display: flex; flex-direction: column; gap: 10px; min-height: 230px; }
.unit__tag { color: var(--muted); text-transform: uppercase; }
.unit p { color: var(--muted); }
.unit__foot { margin-top: auto; padding-top: 16px; display: flex; justify-content: space-between; align-items: center; gap: 12px; border-top: 1px solid var(--line); }
.unit__foot a { font-weight: 600; text-decoration: none; }
.unit__foot a:hover { color: var(--accent); }

/* ---------- IT (dark) ---------- */
.sec--dark { background: var(--dark); color: var(--paper); }
.sec--dark .lead, .sec--dark .sec__n { color: var(--dark-muted); }
.prod { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; }
.prod__card { background: var(--dark-2); border: 1px solid var(--dark-line); border-radius: var(--r); padding: 32px 28px; display: flex; flex-direction: column; gap: 14px; }
.prod__n { width: 36px; height: 36px; display: grid; place-items: center; border: 1px solid var(--accent); color: var(--accent); border-radius: 50%; font-size: 14px; }
.prod__card p { color: var(--dark-muted); }
.prod__card ul { list-style: none; padding: 16px 0 0; margin: auto 0 0; border-top: 1px solid var(--dark-line); display: grid; gap: 8px; }
.prod__card li::before { content: "— "; color: var(--accent); }
.prod__card a { color: var(--accent); }
.it__cta { margin-top: 48px; display: flex; align-items: center; justify-content: space-between; gap: 24px; padding-top: 32px; border-top: 1px solid var(--dark-line); }
.it__cta p { font-size: 19px; max-width: 52ch; }

/* ---------- rules ---------- */
.rules { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); border-top: 1px solid var(--ink); }
.rules p { padding: 28px 24px 28px 0; border-bottom: 1px solid var(--line); font-size: clamp(18px, 1.8vw, 22px); line-height: 1.35; color: var(--muted); }
.rules p:nth-child(odd) { border-right: 1px solid var(--line); }
.rules p:nth-child(even) { padding-left: 24px; }
.rules b { color: var(--ink); font-weight: 600; display: block; font-family: var(--f-display); font-size: clamp(22px, 2.4vw, 30px); letter-spacing: -0.025em; margin-bottom: 6px; }

/* ---------- contact ---------- */
.contact { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(40px, 6vw, 96px); align-items: start; }
.contact__dl { margin: 40px 0 0; display: grid; grid-template-columns: 110px 1fr; gap: 14px 16px; }
.contact__dl dt { color: var(--muted); text-transform: uppercase; padding-top: 3px; }
.contact__dl dd { margin: 0; font-size: 19px; font-weight: 500; }
.contact__dl a { text-decoration: none; }
.contact__dl a:hover { color: var(--accent); }

.form { background: var(--card); border: 1px solid var(--line); border-radius: var(--r); padding: clamp(24px, 3.5vw, 40px); display: grid; gap: 20px; }
.form input[type="text"], .form input[type="tel"], .form select, .form textarea {
  width: 100%; font: 400 17px/1.4 var(--f-body); color: var(--ink);
  background: var(--paper); border: 1.5px solid var(--line); border-radius: var(--r);
  padding: 13px 14px; min-height: 50px;
}
.form textarea { resize: vertical; }
.form input:focus, .form select:focus, .form textarea:focus { border-color: var(--ink); outline: none; }
.form .is-bad { border-color: var(--accent) !important; }
.hp { position: absolute; left: -9999px; width: 1px; height: 1px; opacity: 0; }
.form__msg { font-size: 15px; min-height: 1.4em; }
.form__msg.ok { color: #1d7a3a; }
.form__msg.err { color: var(--accent); }

/* ---------- footer ---------- */
.foot { border-top: 1px solid var(--line); padding-block: 32px; font-size: 14px; }
.foot__in { display: flex; flex-wrap: wrap; gap: 12px 32px; align-items: center; }
.foot__in a { margin-left: auto; color: var(--muted); }

/* ---------- responsive ---------- */
@media (max-width: 1080px) {
  .steps { grid-template-columns: repeat(3, minmax(0, 1fr)); row-gap: 32px; }
  .top__phone { display: none; }
}
@media (max-width: 900px) {
  .hero__grid { grid-template-columns: 1fr; }
  .hero__art { max-width: 560px; }
  .calc { grid-template-columns: 1fr; }
  .calc__res { border-radius: 0 0 var(--r) var(--r); }
  .fleet, .prod { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .contact { grid-template-columns: 1fr; }
  .index__row { grid-template-columns: 48px minmax(0, 1fr) 32px; }
  .index__d { grid-column: 2; grid-row: 2; font-size: 15px; }
  .index__arr { grid-column: 3; grid-row: 1; }
}
@media (max-width: 760px) {
  .burger { display: block; margin-left: auto; }
  .nav {
    position: absolute; top: 64px; left: 0; right: 0;
    flex-direction: column; gap: 0; margin: 0;
    background: var(--paper); border-bottom: 1px solid var(--line);
    padding: 8px var(--gutter) 16px;
    display: none;
  }
  .nav.is-open { display: flex; }
  .nav a { padding: 14px 0; font-size: 18px; border-bottom: 1px solid var(--line); }
  .nav a:last-child { border-bottom: 0; }
  .cols3, .fleet, .prod, .rules { grid-template-columns: 1fr; }
  .rules p, .rules p:nth-child(even) { padding: 22px 0; border-right: 0; }
  .steps { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .it__cta { flex-direction: column; align-items: flex-start; }
  .unit { min-height: 0; }
  .foot__in a { margin-left: 0; }
}
@media (max-width: 420px) {
  .seg--3 { grid-template-columns: 1fr; }
  .seg--3 label + label { border-left: 0; border-top: 1.5px solid var(--ink); }
  .hero__cta .btn { flex: 1 1 100%; }
  .contact__dl { grid-template-columns: 1fr; gap: 2px; }
  .contact__dl dd { margin-bottom: 12px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}

/* ---------- climate: section drawing ---------- */
.sect .s-ground { stroke: var(--ink); stroke-width: 1.4; fill: none; }
.sect .s-hatch { stroke: var(--muted); stroke-width: 1; fill: none; }
.sect .s-cut { fill: #bfbbb2; }
.sect .s-glass { fill: var(--card); stroke-width: 1; }
.sect .s-screed { fill: var(--paper-2); stroke-width: 1; }
.s-heat circle { fill: var(--accent); }
.sect .s-warm { fill: none; stroke: var(--accent); stroke-width: 1.4; stroke-linecap: round; opacity: .75; }
.sect .s-box { fill: var(--card); stroke-width: 1.2; }
.sect .s-out { fill: #d6d3cc; stroke-width: 1.2; }
.sect .s-fan { fill: none; stroke: var(--ink); stroke-width: 1.2; }
.sect .s-thin { fill: none; stroke-width: 1; }
.sect .s-duct { fill: none; stroke: var(--muted); stroke-width: 5; stroke-linecap: square; opacity: .45; }
.sect .s-air { fill: none; stroke: var(--muted); stroke-width: 1.4; stroke-linecap: round; stroke-linejoin: round; }
.sect .s-freon { fill: none; stroke: var(--ink); stroke-width: 1.2; stroke-dasharray: 3 3; }
.sect .s-cool { fill: none; stroke: #3a7ca5; stroke-width: 1.4; stroke-linecap: round; }

/* ---------- climate: blocks ---------- */
.spec { list-style: none; padding: 0; margin: clamp(40px, 6vw, 64px) 0 0; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); border-top: 1px solid var(--line); }
.spec li { padding: 16px 16px 16px 0; display: grid; gap: 6px; border-bottom: 1px solid var(--line); }
.spec span { color: var(--muted); }
.spec b { font-weight: 500; font-size: 16px; color: var(--ink); }
.note { margin-top: 40px; padding: 20px 24px; border-left: 3px solid var(--accent); background: var(--card); font-size: clamp(17px, 1.6vw, 20px); line-height: 1.45; max-width: 860px; }

.cards3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--r); padding: 32px 28px; display: flex; flex-direction: column; gap: 14px; }
.card__n { width: 36px; height: 36px; display: grid; place-items: center; border: 1px solid var(--accent); color: var(--accent); border-radius: 50%; font-size: 14px; }
.card p { color: var(--muted); }

.cols2 { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: clamp(24px, 4vw, 64px); }
.ticks { list-style: none; padding: 0; margin: 14px 0 0; display: grid; gap: 10px; }
.ticks li { color: var(--muted); padding-left: 22px; position: relative; }
.ticks li::before { content: ""; position: absolute; left: 0; top: .6em; width: 8px; height: 8px; border-radius: 50%; background: var(--accent); }

.seg--2x2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.seg--2x2 label + label { border-left: 0; }
.seg--2x2 label:nth-child(even) { border-left: 1.5px solid var(--ink); }
.seg--2x2 label:nth-child(n+3) { border-top: 1.5px solid var(--ink); }

@media (max-width: 900px) {
  .spec { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .cards3 { grid-template-columns: 1fr; }
}
@media (max-width: 760px) {
  .cols2 { grid-template-columns: 1fr; }
}

.sec__split { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(24px, 4vw, 64px); align-items: center; margin-bottom: clamp(40px, 6vw, 72px); }
.sec__split .sec__head { margin-bottom: 0; }
.sec__art { margin: 0; }
.sec__art figcaption { color: var(--muted); margin-top: 8px; text-align: right; }
@media (max-width: 900px) { .sec__split { grid-template-columns: 1fr; } .sec__art { max-width: 560px; } }