/* =========================================================
   Li-Cha — front-end prototype (v4)
   Material concept: galvanized sheet metal (duct material) and technical drawing.
   Brand identity synced with the Li-Cha catalogue: catalogue green, wordmark black,
   the four family colours as a product-coding system, Lexend for codes and figures
   (closest open match to the catalogue's Sinkin Sans), the vector logo, and the
   catalogue's flow-line pattern reinterpreted as live airflow in the hero.
   ========================================================= */

/* ---------- Fonts: Ravi (self-hosted) ----------
   "Ravi FaNum" renders every digit as a Persian digit; plain "Ravi" keeps Latin digits (used for the phone field). */
@font-face { font-family: "Ravi FaNum"; src: url("../fonts/RaviFaNum-Regular.woff2") format("woff2"); font-weight: 400; font-display: swap; }
@font-face { font-family: "Ravi FaNum"; src: url("../fonts/RaviFaNum-SemiBold.woff2") format("woff2"); font-weight: 600; font-display: swap; }
@font-face { font-family: "Ravi"; src: url("../fonts/Ravi-Regular.woff2") format("woff2"); font-weight: 400; font-display: swap; }
@font-face { font-family: "Ravi"; src: url("../fonts/Ravi-SemiBold.woff2") format("woff2"); font-weight: 600; font-display: swap; }
@font-face { font-family: "Lexend"; src: url("../fonts/Lexend-latin.woff2") format("woff2"); font-weight: 100 900; font-display: swap; unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+2000-206F, U+2074, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }

/* ---------- Tokens ---------- */
:root {
  /* color */
  --galv:      #EDEFF0;  /* light galvanized sheet — main surface (catalogue paper is white) */
  --zinc:      #F8F9F9;  /* raised surface                    */
  --graphite:  #24272A;  /* catalogue wordmark black          */
  --graphite-2:#1D2022;  /* dark scenes                       */
  --steel:     #6F7A7F;  /* secondary text, drawing notes     */
  --rule:      #C3C9CC;  /* seams and dividers on light       */
  --green:     #009933;  /* catalogue green — air, flow, action */
  --green-deep:#1A7B32;  /* logo impeller green               */
  --green-ink: #137A2E;  /* green text on light surfaces      */
  --smoke:     #B8743A;  /* smoke particles in the stagnant-air scene */

  /* product families — the catalogue's colour coding */
  --c-axial:    #EFDF2B;
  --c-backward: #359B73;
  --c-forward:  #68BCEB;
  --c-smoke:    #EE242C;
  --c-calc:     #80D07B;

  /* type */
  --f-display: "Ravi FaNum", "Ravi", system-ui, sans-serif;
  --f-body: "Ravi FaNum", "Ravi", system-ui, sans-serif;
  --f-lat: "Lexend", "Ravi FaNum", system-ui, sans-serif;
  --t-hero: clamp(2.9rem, 7.6vw, 7.6rem);
  --t-h2:   clamp(1.9rem, 3.9vw, 3.8rem);
  --t-h3:   clamp(1.3rem, 1.9vw, 1.75rem);
  --t-lead: clamp(1.08rem, 1.35vw, 1.3rem);
  --t-body: 1rem;
  --t-small: .875rem;

  /* spacing — 8px base */
  --s1: .5rem; --s2: 1rem; --s3: 1.5rem; --s4: 2rem; --s5: 3rem; --s6: 4.5rem; --s7: 7rem;
  --gutter: clamp(16px, 4vw, 64px);
  --nav-h: 72px;
  --max: 1360px;
}

/* ---------- Base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
html.lenis, html.lenis body { height: auto; }
.lenis.lenis-smooth { scroll-behavior: auto !important; }
.lenis.lenis-stopped { overflow: hidden; }
body {
  margin: 0; background: var(--galv); color: var(--graphite);
  font-family: var(--f-body); font-size: var(--t-body); line-height: 1.9;
  font-feature-settings: "ss01";
  overflow-x: clip;
  -webkit-font-smoothing: antialiased;
  font-synthesis: none;
}
img, svg { display: block; max-width: 100%; }
h1, h2, h3, h4 { font-family: var(--f-display); font-weight: 600; line-height: 1.35; margin: 0; }
h2 { font-size: var(--t-h2); }
h3 { font-size: var(--t-h3); font-weight: 600; }
p { margin: 0; }
a { color: inherit; }
ul, ol { margin: 0; padding: 0; list-style: none; }
::selection { background: var(--green); color: #fff; }
:focus-visible { outline: 2px solid var(--green); outline-offset: 3px; }
[data-theme="green"] :focus-visible { outline-color: #fff; }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.skip { position: fixed; top: 8px; right: 8px; z-index: 100; padding: 8px 14px; background: var(--graphite); color: var(--zinc); transform: translateY(-200%); }
.skip:focus { transform: none; }

.wrap { width: 100%; max-width: var(--max); margin-inline: auto; padding-inline: var(--gutter); }
.scene { position: relative; }
[data-theme="dark"] { background: var(--graphite-2); color: var(--zinc); }
[data-theme="green"] { background: var(--green); color: #fff; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: .6em;
  padding: .85em 1.5em; border: 2px solid currentColor; border-radius: 2px;
  font: 600 1rem/1.4 var(--f-body); text-decoration: none; cursor: pointer;
  transition: background-color .2s, color .2s, border-color .2s;
}
.btn--solid { background: var(--green); border-color: var(--green); color: #fff; }
.btn--solid:hover { background: var(--graphite); border-color: var(--graphite); color: var(--zinc); }
.btn--line { background: transparent; color: var(--graphite); border-color: var(--graphite); }
.btn--line:hover { background: var(--graphite); color: var(--zinc); }
.btn--dark { background: var(--graphite); border-color: var(--graphite); color: var(--zinc); }
.btn--dark:hover { background: transparent; color: var(--graphite); }
[data-theme="green"] .btn--dark:hover { color: #fff; border-color: #fff; }

/* tags = real sub-types / services */
.tags { display: flex; flex-wrap: wrap; gap: .5rem; margin-top: var(--s2); }
.tags li { font-size: var(--t-small); line-height: 1.6; padding: .2em .75em; border: 1px solid var(--rule); background: var(--zinc); }
[data-theme="dark"] .tags li { border-color: #4A5255; background: transparent; }

/* ---------- Navigation ---------- */
.nav { position: fixed; inset: 0 0 auto 0; z-index: 50; transition: transform .35s ease; }
.nav.is-hidden { transform: translateY(-100%); }
.nav__bar {
  height: var(--nav-h); display: flex; align-items: center; gap: var(--s4);
  padding-inline: var(--gutter);
  background: rgba(238, 241, 242, .9); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--rule);
}
.nav__logo img { height: 40px; width: auto; }
.nav__links { display: flex; gap: var(--s3); margin-inline-start: auto; }
.nav__links a { text-decoration: none; font-weight: 400; padding: .4em 0; background: linear-gradient(var(--green), var(--green)) no-repeat right bottom / 0 2px; transition: background-size .25s; }
.nav__links a:hover, .nav__links a.is-active { background-size: 100% 2px; }
.nav__cta { padding: .55em 1.1em; font-size: .95rem; }
.nav__progress { height: 2px; background: transparent; }
.nav__progress i { display: block; height: 100%; background: var(--green); transform-origin: right; transform: scaleX(0); }
.nav__toggle { display: none; margin-inline-start: auto; width: 44px; height: 44px; border: 0; background: none; padding: 10px; cursor: pointer; }
.nav__toggle span:not(.sr) { display: block; height: 2px; background: var(--graphite); margin: 7px 0; transition: transform .25s; }
.nav__toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(4.5px) rotate(45deg); }
.nav__toggle[aria-expanded="true"] span:nth-child(2) { transform: translateY(-4.5px) rotate(-45deg); }
.mobile-menu { background: var(--zinc); border-bottom: 1px solid var(--rule); padding: var(--s2) var(--gutter) var(--s4); display: grid; }
.mobile-menu[hidden] { display: none; }
.mobile-menu a { font: 600 1.5rem/1.2 var(--f-display); text-decoration: none; padding: .6em 0; border-bottom: 1px solid var(--rule); }

/* ---------- Traveling impeller ---------- */
.fan-dock {
  position: fixed; top: 0; left: 0; z-index: 20; pointer-events: none;
  width: var(--fan-size, 560px); height: var(--fan-size, 560px);
  will-change: transform;
}
.fan-cta, .fan-spin { width: 100%; height: 100%; }
.fan-spin { will-change: transform; }
.impeller { width: 100%; height: 100%; overflow: visible; }
.impeller path { fill: var(--fan-c, var(--green-deep)); transition: fill .4s; }
.imp-arc { fill: none; stroke: var(--fan-c, var(--green)); stroke-width: 9; stroke-linecap: round; transition: stroke .4s; }
.imp-hole { fill: var(--fan-hole, var(--galv)); transition: fill .4s; }
body.on-dark { --fan-hole: var(--graphite-2); }
body.on-green { --fan-c: #fff; --fan-hole: var(--green); }
body.on-dark { --fan-c: var(--green); }
html:not(.js) .fan-dock { display: none; }

/* =========================================================
   01 HERO
   ========================================================= */
.hero { min-height: 100svh; display: flex; flex-direction: column; justify-content: center; overflow: hidden; background: var(--galv); padding-top: var(--nav-h); }
.hero__flow { position: absolute; inset: 0; width: 100%; height: 100%; }
.hero__inner { position: relative; z-index: 2; }
.hero__title { font-size: var(--t-hero); font-weight: 600; line-height: 1.25; max-width: 7.5em; }
.hero__title .line { display: block; overflow: hidden; padding-block: .08em .16em; margin-block: -.08em -.16em; }
.hero__title .line > span { display: inline-block; }
.hero__lead { font-size: var(--t-lead); max-width: 30em; margin-top: var(--s4); line-height: 1.8; }
.hero__actions { display: flex; flex-wrap: wrap; gap: var(--s2); margin-top: var(--s4); }
.hero__facts { position: relative; z-index: 2; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--s4); margin-top: var(--s6); }
.hero__facts li { border-top: 2px solid var(--graphite); padding-top: var(--s2); display: grid; gap: .2rem; max-width: 22em; }
.hero__facts b { font: 600 1.25rem/1.3 var(--f-display); }
.hero__facts span { font-size: var(--t-small); color: var(--steel); line-height: 1.6; }
.hero__cue { position: absolute; z-index: 2; bottom: var(--s3); left: var(--gutter); display: flex; align-items: center; gap: .6rem; font-size: var(--t-small); color: var(--steel); }
.hero__cue i { width: 1px; height: 40px; background: var(--steel); transform-origin: top; animation: cue 1.8s ease-in-out infinite; }
@keyframes cue { 0% { transform: scaleY(0); } 50% { transform: scaleY(1); transform-origin: top; } 51% { transform-origin: bottom; } 100% { transform: scaleY(0); transform-origin: bottom; } }

/* =========================================================
   02 PROBLEM — stagnant air
   ========================================================= */
.problem__pin { min-height: 100svh; display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); align-items: center; gap: var(--s5); padding: calc(var(--nav-h) + var(--s4)) var(--gutter) var(--s5); max-width: 1600px; margin-inline: auto; }
.problem__text { padding: 0; display: grid; gap: var(--s5); }
.problem__steps { display: grid; }
.pstep { grid-area: 1 / 1; transition: opacity .45s, transform .45s; }
.pstep:not(.is-on) { opacity: 0; transform: translateY(14px); pointer-events: none; }
.pstep h2 { font-size: clamp(1.9rem, 3.4vw, 3.2rem); }
.pstep p { margin-top: var(--s3); color: #B7C0C3; max-width: 30em; font-size: var(--t-lead); line-height: 1.8; }
.gauge { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: var(--s2); font-size: var(--t-small); color: #B7C0C3; max-width: 26rem; }
.gauge__bar { height: 6px; background: #3D4447; position: relative; overflow: hidden; }
.gauge__bar i { position: absolute; inset: 0; background: var(--smoke); transform-origin: right; transform: scaleX(.18); }
.gauge small { font-size: .75rem; opacity: .7; }
.plan { width: 100%; height: auto; overflow: visible; color: #8C969A; }
.pl-wall { fill: #2A3033; stroke: #8C969A; stroke-width: 2; }
.pl-shaft { stroke: #8C969A; stroke-width: 1.5; color: #8C969A; }
.pl-ramp { fill: none; stroke: #8C969A; stroke-width: 2; }
.pl-stalls path { stroke: #4E575A; stroke-width: 1.5; fill: none; }
.pl-cols rect { fill: #4E575A; }
.pl-label { fill: #B7C0C3; font: 400 14px var(--f-body); }
.pl-flow path { fill: none; stroke: var(--green); stroke-width: 2.5; stroke-linecap: round; stroke-dasharray: 10 14; animation: flowdash2 1.1s linear infinite; }
@keyframes flowdash2 { to { stroke-dashoffset: -48; } }
.pl-jetlabel { fill: var(--green); }
.puff { mix-blend-mode: screen; }

/* =========================================================
   03 ABOUT
   ========================================================= */
.about { padding-block: var(--s7); background: var(--galv); }
.about__grid { display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); gap: var(--s5) var(--s6); align-items: start; }
.about__kicker { grid-column: 1 / -1; font-size: var(--t-h2); color: var(--green-ink); }
.about__statement { font: 400 clamp(1.45rem, 2.55vw, 2.35rem)/1.75 var(--f-body); max-width: 26em; }
.about__statement .w { opacity: .16; transition: none; }
.plate {
  position: relative; margin: 0; padding: var(--s4) var(--s4) var(--s3);
  background: linear-gradient(160deg, #F3F5F6, #D7DCDE);
  border: 1px solid #AEB6BA; box-shadow: inset 0 0 0 6px #E9ECED, inset 0 0 0 7px #C3C9CC;
}
.plate__head { display: flex; align-items: center; justify-content: space-between; gap: var(--s2); padding-bottom: var(--s2); border-bottom: 2px solid var(--graphite); }
.plate__head img { height: 30px; width: auto; }
.plate__head span { font-weight: 600; font-size: var(--t-small); }
.plate__rows > div { display: grid; grid-template-columns: 8.5em 1fr; gap: var(--s2); padding: .85rem 0; border-bottom: 1px solid #B9C0C3; }
.plate__rows > div:last-child { border-bottom: 0; }
.plate dt { font: 600 1.05rem/1.6 var(--f-display); }
.plate dd { margin: 0; font-size: .95rem; line-height: 1.7; color: #4C5558; }
.rivet { position: absolute; width: 9px; height: 9px; border-radius: 50%; background: radial-gradient(circle at 35% 35%, #fff, #9AA3A7 60%, #6F7A7F); }
.r1 { top: 12px; right: 12px; } .r2 { top: 12px; left: 12px; } .r3 { bottom: 12px; right: 12px; } .r4 { bottom: 12px; left: 12px; }

/* =========================================================
   04 PROCESS
   ========================================================= */
.process { background: var(--zinc); }
.process__pin { padding-block: var(--s7) var(--s6); }
.process__head { display: grid; grid-template-columns: minmax(0, 6fr) minmax(0, 5fr); gap: var(--s4); align-items: end; margin-bottom: var(--s6); }
.process__head p { font-size: var(--t-lead); color: #4C5558; max-width: 28em; line-height: 1.8; }
.process__track { position: relative; }
.duct { position: absolute; background: var(--galv); }
.duct__fill { position: absolute; background: var(--green); }
.station { position: relative; }
.station__no { display: block; font: 600 clamp(3.6rem, 6vw, 5.6rem)/1 var(--f-display); color: transparent; -webkit-text-stroke: 1.5px var(--graphite); transition: color .4s, -webkit-text-stroke-color .4s; }
.station.is-active .station__no { color: var(--green); -webkit-text-stroke-color: var(--green); }
.station h3 { margin-top: var(--s3); }
.station p { margin-top: var(--s1); color: #4C5558; max-width: 24em; }

/* desktop: horizontal journey along a duct */
@media (min-width: 1024px) and (prefers-reduced-motion: no-preference) {
  .js .process__pin { height: 100vh; display: flex; flex-direction: column; justify-content: center; padding-block: calc(var(--nav-h) + var(--s3)) var(--s4); }
  .js .process__head { margin-bottom: var(--s5); }
  .js .process__viewport { overflow: hidden; }
  .js .process__track { display: flex; width: max-content; padding-inline: var(--gutter) 20vw; padding-top: 92px; }
  .js .duct { top: 0; right: 0; left: 0; height: 48px; border-block: 2px solid var(--graphite);
 }
  .js .duct__fill { inset: 10px 0; transform-origin: right; transform: scaleX(0); }
  .js .station { width: min(36vw, 500px); padding-inline: 0 var(--s5); padding-top: var(--s4); }
  .js .station::before { content: ""; position: absolute; top: -44px; right: 0; width: 2px; height: 44px; background: var(--graphite); }
  .js .station::after { content: ""; position: absolute; top: -100px; right: -4px; width: 10px; height: 64px; background: var(--graphite); }
}
/* tablet / mobile / reduced motion: vertical duct */
@media (max-width: 1023px), (prefers-reduced-motion: reduce) {
  .process__pin { padding-block: var(--s6); }
  .process__head { grid-template-columns: 1fr; }
  .process__track { display: grid; gap: var(--s5); padding-inline: var(--gutter); }
  .duct { top: 0; bottom: 0; right: var(--gutter); width: 16px; border-inline: 2px solid var(--graphite); }
  .duct__fill { inset: 0 3px; transform-origin: top; transform: scaleY(0); }
  .station { padding-right: 48px; }
}
html:not(.js) .duct__fill { transform: none; }

/* =========================================================
   05 CFD
   ========================================================= */
.cfd__pin { position: relative; height: 100svh; min-height: 560px; overflow: hidden; }
.cfd__canvas { position: absolute; inset: 0; width: 100%; height: 100%; }
.cfd__text { position: relative; z-index: 2; height: 100%; display: flex; flex-direction: column; justify-content: center; align-items: flex-start; pointer-events: none; }
.cfd__text h2 { max-width: 8em; }
.cfd__text p { margin-top: var(--s3); max-width: 26em; font-size: var(--t-lead); color: #C3CBCE; line-height: 1.8; background: rgba(38, 43, 45, .78); padding: .2em 0; }
.cfd__text .cfd__note { font-size: .8rem; color: #8C969A; background: none; }
.cfd__legend { position: absolute; z-index: 2; bottom: var(--s4); left: var(--gutter); display: flex; align-items: center; gap: .75rem; font-size: .8rem; color: #8C969A; }
.cfd__legend i { width: 120px; height: 6px; background: linear-gradient(to left, #5A6366, var(--green)); }

/* =========================================================
   06 PRODUCTS
   ========================================================= */
.products { padding-block: var(--s7) var(--s6); background: var(--galv); }
.products__head { display: grid; grid-template-columns: minmax(0, 6fr) minmax(0, 5fr); gap: var(--s4); align-items: end; margin-bottom: var(--s5); }
.products__head p, .apps__head p, .projects__head p { font-size: var(--t-lead); max-width: 28em; line-height: 1.8; color: #4C5558; }
.products__grid { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: var(--s6); align-items: start; }
.family { min-height: 62vh; padding-block: var(--s5); border-top: 1px solid var(--rule); display: flex; flex-direction: column; justify-content: center; }
.family h3 { font-size: clamp(1.6rem, 2.6vw, 2.4rem); transition: color .35s; }
.family p { margin-top: var(--s2); max-width: 30em; color: #4C5558; }
.js .family:not(.is-active) h3 { color: #9AA3A7; }
.placeholder-note { font-size: var(--t-small); color: var(--steel); padding-block: var(--s3); border-top: 1px dashed var(--steel); }
.products__sheet { position: sticky; top: calc(var(--nav-h) + var(--s3)); }
.sheet { position: relative; background: var(--zinc); border: 2px solid var(--graphite); aspect-ratio: 4 / 3.9; max-height: calc(100vh - var(--nav-h) - 3rem); width: 100%; display: flex; flex-direction: column;
  background-image: linear-gradient(var(--rule) 1px, transparent 1px), linear-gradient(90deg, var(--rule) 1px, transparent 1px); background-size: 32px 32px; background-position: -1px -1px; }
.sheet__drawings { position: relative; flex: 1; margin: var(--s3); }
.drawing { position: absolute; inset: 0; width: 100%; height: 100%; }
.js .drawing { opacity: 0; }
.js .drawing.is-active { opacity: 1; }
.ln, .ln-g, .ln-s { fill: none; stroke-width: 1.6; stroke-linecap: round; stroke-linejoin: round; vector-effect: non-scaling-stroke; }
.ln { stroke: var(--graphite); }
.ln.thin { stroke-width: 1; }
.ln-g { stroke: var(--green); stroke-width: 2; }
.ln-s { stroke: var(--smoke); stroke-width: 2; }
.fill-g { fill: var(--green); }
.sheet__title { display: grid; grid-template-columns: 1fr auto auto auto; border-top: 2px solid var(--graphite); background: var(--zinc); }
.sheet__title > span { padding: .6rem 1rem; font-size: var(--t-small); line-height: 1.5; }
.sheet__name { font: 600 1.05rem/1.5 var(--f-display) !important; }
.sheet__meta { border-right: 1px solid var(--graphite); }
.sheet__meta b { font-weight: 400; color: var(--steel); }
.sheet__meta em { font-style: normal; }

/* =========================================================
   07 APPLICATIONS
   ========================================================= */
.apps { padding-block: var(--s7) var(--s6); background: var(--zinc); }
.apps__head { display: grid; grid-template-columns: minmax(0, 6fr) minmax(0, 5fr); gap: var(--s4); align-items: end; margin-bottom: var(--s5); }
.apps__grid { display: grid; grid-template-columns: minmax(0, 6fr) minmax(0, 5fr); gap: var(--s6); align-items: start; }
.apps__visual { position: sticky; top: calc(var(--nav-h) + var(--s3)); order: 2; }
.section-cut { width: 100%; height: auto; max-height: calc(100vh - var(--nav-h) - 3rem); color: var(--graphite); }
.cut-ground { stroke: var(--graphite); stroke-width: 3; }
.zone { fill: var(--green); fill-opacity: 0; stroke: none; mix-blend-mode: multiply; transition: fill-opacity .35s; }
.zone.is-on { fill-opacity: .32; }
.flow { fill: none; stroke: var(--green-ink); stroke-width: 2.5; stroke-linecap: round; stroke-dasharray: 8 10; opacity: 0; transition: opacity .35s; }
.flow.is-on { opacity: 1; animation: flowdash 1s linear infinite; }
@keyframes flowdash { to { stroke-dashoffset: -36; } }
.apps__list { order: 1; }
.app { padding-block: var(--s4); border-top: 1px solid var(--rule); min-height: 34vh; display: flex; flex-direction: column; justify-content: center; cursor: default; }
.app h3 { transition: color .3s; }
.app p { margin-top: var(--s1); color: #4C5558; max-width: 28em; }
.js .app:not(.is-active) h3 { color: #9AA3A7; }

/* =========================================================
   08 PROJECTS & TRUST
   ========================================================= */
.projects { padding-block: var(--s7); }
.projects__head { display: grid; grid-template-columns: minmax(0, 6fr) minmax(0, 5fr); gap: var(--s4); align-items: end; margin-bottom: var(--s5); }
.projects__head p { color: #B7C0C3; }
.projects__grid { display: grid; grid-template-columns: repeat(6, minmax(0, 1fr)); gap: var(--s3); }
.proj { margin: 0; }
.proj--a { grid-column: span 4; grid-row: span 2; }
.proj--b, .proj--c { grid-column: span 2; }
.proj--d, .proj--e { grid-column: span 3; }
.proj__img { position: relative; aspect-ratio: 4 / 3; overflow: hidden; background: repeating-linear-gradient(-45deg, #343B3E 0 2px, transparent 2px 14px), #2B3134; border: 1px solid #4A5255; }
.proj--a .proj__img { aspect-ratio: auto; height: calc(100% - 4.5rem); min-height: 320px; }
.proj__img::after { content: attr(data-ph); position: absolute; inset: 0; display: grid; place-items: center; color: #7C878B; font-size: var(--t-small); }
.proj figcaption { display: grid; padding-top: .75rem; }
.proj figcaption b { font: 600 1.15rem/1.5 var(--f-display); }
.proj figcaption span { font-size: var(--t-small); color: #8C969A; }
.trust { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--s4); margin-top: var(--s7); }
.trust__slot { border-top: 2px solid var(--zinc); padding-top: var(--s3); }
.trust__slot h3 { font-size: 1.3rem; }
.trust__slot p { margin-top: var(--s1); font-size: .95rem; color: #9AA3A7; }
.logo-ph { display: grid; grid-template-columns: repeat(4, 1fr); gap: .5rem; margin-top: var(--s3); }
.logo-ph i { height: 44px; border: 1px dashed #5A6366; }

/* =========================================================
   09 CONTACT
   ========================================================= */
.contact { padding-block: var(--s7); overflow: hidden; }
.contact__grid { display: grid; grid-template-columns: minmax(0, 6fr) minmax(0, 5fr); gap: var(--s6); align-items: start; }
.contact h2 { font-size: clamp(2.2rem, 4.4vw, 4.2rem); max-width: 10em; }
.contact__intro > p { margin-top: var(--s3); font-size: var(--t-lead); max-width: 28em; line-height: 1.8; }
.contact__info { margin-top: var(--s5); display: grid; }
.contact__info > div { display: grid; grid-template-columns: 5em 1fr; padding: .7rem 0; border-top: 1px solid rgba(255, 255, 255, .35); }
.contact__info dt { font-weight: 600; }
.contact__info dd { margin: 0; }
.form { display: grid; gap: var(--s3); background: var(--zinc); padding: var(--s4); border: 2px solid var(--graphite); }
.form label { display: grid; gap: .3rem; font-weight: 600; font-size: .95rem; }
.form input, .form select, .form textarea {
  font: 400 1rem/1.6 var(--f-body); color: var(--graphite); background: var(--galv);
  border: 0; border-bottom: 2px solid var(--graphite); border-radius: 0; padding: .6rem .75rem; width: 100%;
}
.form input[type="tel"] { font-family: "Ravi", system-ui, sans-serif; }
.form input:focus, .form select:focus, .form textarea:focus { outline: 2px solid var(--green); outline-offset: 0; }
.form .btn { justify-self: start; }
.form__status { font-size: var(--t-small); min-height: 1.5em; }

/* ---------- Footer ---------- */
.footer { padding-block: var(--s6) var(--s4); }
.footer__grid { display: grid; grid-template-columns: minmax(0, 4fr) repeat(3, minmax(0, 2fr)); gap: var(--s4); }
.footer__brand img { height: 46px; width: auto; }
.footer__brand p { margin-top: var(--s2); color: #9AA3A7; max-width: 22em; font-size: .95rem; }
.footer h4 { font-size: 1.05rem; margin-bottom: var(--s2); }
.footer li { color: #9AA3A7; font-size: .92rem; line-height: 2.1; }
.footer__base { display: flex; justify-content: space-between; margin-top: var(--s6); padding-top: var(--s2); border-top: 1px solid #4A5255; color: #8C969A; font-size: var(--t-small); }


/* =========================================================
   V2 — POLISH: material texture, technical drawing system, details
   ========================================================= */

/* galvanized spangle: a very low-contrast static grain on light surfaces */
:root {
  --grain: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='220' height='220'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 .18 0 0 0 0 .2 0 0 0 0 .21 0 0 0 .07 0'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}
.hero, .about, .process, .products, .apps { background-image: var(--grain); }
[data-theme="dark"] { background-image: var(--grain); }

/* seam between light sections — reads like a duct joint */
.about, .process, .products, .apps { border-top: 1px solid var(--rule); box-shadow: inset 0 1px 0 #F6F8F8; }

/* ---------- Technical drawing system (product sheet + building section) ---------- */
.tech * { vector-effect: non-scaling-stroke; stroke-linecap: round; stroke-linejoin: round; }
.tech .o  { fill: none; stroke: var(--graphite); stroke-width: 1.7; }
.tech .t  { fill: none; stroke: var(--graphite); stroke-width: .9; }
.tech .h  { fill: none; stroke: var(--steel); stroke-width: .9; stroke-dasharray: 5 3; }
.tech .c  { fill: none; stroke: var(--steel); stroke-width: .8; stroke-dasharray: 14 3 2 3; }
.tech .pr { fill: none; stroke: #9AA3A7; stroke-width: .7; stroke-dasharray: 2 4; }
.tech .d, .tech .ld { fill: none; stroke: #5B666B; stroke-width: .8; }
.tech .dh { fill: #5B666B; stroke: none; }
.tech .dt { fill: #3E474A; font: 600 13px var(--f-body); font-style: italic; }
.tech .g  { fill: none; stroke: var(--green); stroke-width: 2.2; }
.tech .gd { fill: none; stroke: var(--green); stroke-width: 1.2; stroke-dasharray: 3 4; }
.tech .gh { fill: var(--green); stroke: var(--green); stroke-width: 1; }
.tech .s  { fill: none; stroke: var(--smoke); stroke-width: 2; }
.tech .s2 { fill: none; stroke: var(--smoke); stroke-width: 1.2; }
.tech .sh { fill: var(--smoke); stroke: var(--smoke); stroke-width: 1; }
.tech .fa  { fill: #E2E6E8; fill-opacity: var(--fo, 1); }
.tech .fa2 { fill: #F4F6F7; fill-opacity: var(--fo, 1); }
.tech .fb  { fill: #C9D0D3; fill-opacity: var(--fo, 1); }
.tech .fw  { fill: #F7F9F9; fill-opacity: var(--fo, 1); }
.tech .fg  { fill: var(--green); }
.tech .hx  { fill: url(#hx45); fill-opacity: var(--fo, 1); }
.tech .hx0 { fill: url(#hx45l); stroke: none; }
.tech .dotf, .tech .ldot { fill: var(--graphite); stroke: none; }
.tech .bal { fill: #F7F9F9; stroke: var(--graphite); stroke-width: 1.1; }
.tech .bt  { fill: var(--graphite); font: 600 12px var(--f-body); }
.drawing .bt, .drawing .dt, .drawing .bal, .drawing .ld, .drawing .ldot { transition: opacity .4s; }

/* drawing sheet: inner frame, finer two-level grid, parts list, title block */
.sheet {
  background-image:
    linear-gradient(rgba(185,192,195,.55) 1px, transparent 1px), linear-gradient(90deg, rgba(185,192,195,.55) 1px, transparent 1px),
    linear-gradient(rgba(185,192,195,.3) 1px, transparent 1px), linear-gradient(90deg, rgba(185,192,195,.3) 1px, transparent 1px);
  background-size: 80px 80px, 80px 80px, 16px 16px, 16px 16px;
  background-position: -1px -1px;
}
.sheet::before { content: ""; position: absolute; inset: 7px; border: 1px solid var(--graphite); pointer-events: none; z-index: 0; }
.sheet > * { position: relative; z-index: 1; }
.sheet__drawings { margin: var(--s4) var(--s4) var(--s2); }
.sheet__parts { display: flex; flex-wrap: wrap; gap: .35rem 1.1rem; margin: 0 var(--s4) var(--s3); padding: .7rem 0 0; border-top: 1px dashed var(--steel); min-height: 2.6rem; }
.sheet__parts li { display: flex; align-items: center; gap: .45rem; font-size: .85rem; line-height: 1.4; color: #3E474A; }
.sheet__parts i { display: inline-grid; place-items: center; width: 1.45rem; height: 1.45rem; border: 1px solid var(--graphite); border-radius: 50%; font: 600 .78rem/1 var(--f-body); font-style: normal; background: #F7F9F9; }
.sheet__mark { display: grid; place-items: center; border-right: 1px solid var(--graphite); padding: .35rem .9rem !important; }
.sheet__mark img { height: 22px; width: auto; }

/* parking plan (dark): car symbols + detailed jet fans */
.pl-cars { color: #74808A; }
.jf-body { fill: #2A3033; stroke: var(--green); stroke-width: 2; }
.jf-sil  { fill: url(#hx45l); stroke: var(--green); stroke-width: 1; }
.jf-hub  { fill: none; stroke: var(--green); stroke-width: 1.5; }
.jf-mouth { fill: none; stroke: var(--green); stroke-width: 2; }

/* process stations: number + line icon */
.station__top { display: flex; align-items: flex-end; justify-content: space-between; gap: var(--s2); max-width: 24rem; }
.station__icon { width: 44px; height: 44px; flex: none; fill: none; stroke: var(--graphite); stroke-width: 1.6; stroke-linecap: round; stroke-linejoin: round; transition: stroke .4s; }
.station.is-active .station__icon { stroke: var(--green-ink); }

/* hero: construction geometry around the impeller (static, fades on dive) */
.fan-cta { position: relative; }
.fan-construct { position: absolute; inset: 0; width: 100%; height: 100%; max-width: none; overflow: visible; pointer-events: none; }
.fan-construct * { fill: none; vector-effect: non-scaling-stroke; }
.fc-ring { stroke: #B3BBBF; stroke-width: 1; }
.fc-dash { stroke: #9AA3A7; stroke-width: 1; stroke-dasharray: 3 6; }
.fc-ticks path { stroke: #8C969A; stroke-width: 1; }
.fc-cl { stroke: #9AA3A7; stroke-width: .8; stroke-dasharray: 18 4 3 4; }
body.on-dark .fan-construct, body.on-green .fan-construct { opacity: 0; }

/* hero title: tighter tracking on the large size */
.hero__title { letter-spacing: -.01em; }
.hero__facts li { position: relative; }
.hero__facts li::before { content: ""; position: absolute; top: -2px; right: 0; width: 28px; height: 2px; background: var(--green); }

/* projects placeholders: softer blueprint pattern */
.proj__img { background: linear-gradient(rgba(255,255,255,.035) 1px, transparent 1px) 0 0 / 24px 24px, linear-gradient(90deg, rgba(255,255,255,.035) 1px, transparent 1px) 0 0 / 24px 24px, #2B3134; }


/* =========================================================
   V4 — brand sync components (codes, families, selector, trust)
   ========================================================= */
.lat { font-family: var(--f-lat); direction: ltr; unicode-bidi: isolate; }
.nav__logo img { height: 44px; }
.footer__brand img { height: 52px; }
.footer__motto { margin-top: var(--s3); font: 300 .9rem/1.4 var(--f-lat) !important; letter-spacing: .12em; color: #C3CBCE !important; }
.footer a { text-decoration: none; }
.footer a:hover { color: #fff; text-decoration: underline; text-underline-offset: .3em; }
@media (min-width: 1024px) { .footer__grid { grid-template-columns: minmax(0, 4fr) repeat(4, minmax(0, 2fr)); } }
.hero__kicker { display: flex; align-items: center; gap: .8rem; margin-bottom: var(--s3); font: 300 .92rem/1.4 var(--f-lat); letter-spacing: .14em; color: var(--steel); }
.hero__kicker::before { content: ""; width: 34px; height: 2px; background: var(--green); }
.about__motto { margin-top: var(--s4); display: flex; flex-wrap: wrap; align-items: baseline; gap: .4rem 1.2rem; }
.about__motto .lat { font: 300 clamp(1rem, 1.4vw, 1.25rem)/1.3 var(--f-lat); letter-spacing: .1em; }
.about__motto .lat b { font-weight: 600; color: var(--green-ink); }
.about__motto span:not(.lat) { color: var(--steel); }

/* family colour coding: used as a thin stripe on codes and families, never as page chrome */
[data-family="axial"]    { --fc: var(--c-axial); }
[data-family="backward"] { --fc: var(--c-backward); }
[data-family="forward"]  { --fc: var(--c-forward); }
[data-family="smoke"]    { --fc: var(--c-smoke); }
[data-family="calc"]     { --fc: var(--c-calc); }
[data-family="brand"]    { --fc: var(--green); }

/* a series code, written like on the fan's own nameplate */
.scode { display: inline-flex; align-items: center; gap: .5rem; font: 500 .95rem/1 var(--f-lat); direction: ltr; letter-spacing: .03em; white-space: nowrap; }
.scode::before { content: ""; width: 4px; height: 1.1em; background: var(--fc, var(--green)); }
.scode b { font-weight: 600; }
.scode--lg { font-size: clamp(1.4rem, 2.4vw, 2.1rem); font-weight: 300; }
.scode--lg::before { width: 6px; }

/* ---------- products: real families on the drawing sheet ---------- */
.family__kicker { display: flex; align-items: center; gap: .6rem; margin-bottom: var(--s2); font: 300 .9rem/1.4 var(--f-lat); letter-spacing: .06em; color: var(--steel); direction: ltr; justify-content: flex-end; }
.family__kicker i { width: 22px; height: 4px; background: var(--fc); }
.series-chips { display: flex; flex-wrap: wrap; gap: .5rem; margin-top: var(--s3); }
.series-chip { display: inline-grid; gap: .1rem; padding: .55rem .8rem .5rem; background: var(--zinc); border: 1px solid var(--rule); text-decoration: none; transition: border-color .2s, background-color .2s; min-width: 7rem; }
.series-chip:hover, .series-chip:focus-visible { border-color: var(--graphite); background: #fff; }
.series-chip .scode { font-size: .95rem; }
.series-chip small { font-size: .78rem; color: var(--steel); line-height: 1.5; }
.family__stats { margin-top: var(--s3); display: flex; flex-wrap: wrap; gap: .3rem 1.6rem; }
.family__stats div { display: grid; }
.family__stats dt { font-size: .78rem; color: var(--steel); }
.family__stats dd { margin: 0; font: 400 1rem/1.4 var(--f-lat); direction: ltr; text-align: right; }
.family .btn { margin-top: var(--s3); align-self: flex-start; font-size: .92rem; padding: .6em 1.1em; }

/* ---------- selector ---------- */
.selector { padding-block: var(--s7); background: var(--zinc); border-top: 1px solid var(--rule); }
.selector__head { display: grid; grid-template-columns: minmax(0, 6fr) minmax(0, 5fr); gap: var(--s4); align-items: end; margin-bottom: var(--s5); }
.selector__head p { font-size: var(--t-lead); color: #4C5558; max-width: 30em; line-height: 1.8; }
.sel { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: var(--s6); align-items: start; }
.sel__form { position: sticky; top: calc(var(--nav-h) + var(--s3)); display: grid; gap: var(--s3); }
.sel__mode { display: grid; grid-template-columns: 1fr 1fr; border: 2px solid var(--graphite); }
.sel__mode button { font: 600 .95rem/1.4 var(--f-body); padding: .75rem; border: 0; background: transparent; cursor: pointer; color: var(--graphite); }
.sel__mode button[aria-pressed="true"] { background: var(--graphite); color: #fff; }
.field { display: grid; gap: .35rem; }
.field > span { font-weight: 600; font-size: .92rem; }
.field small { color: var(--steel); font-size: .8rem; }
.field input, .field select { font: 400 1.05rem/1.4 var(--f-body); color: var(--graphite); background: #fff; width: 100%; border: 0; border-bottom: 2px solid var(--graphite); border-radius: 0; padding: .65rem .5rem; }
.field input[type="number"] { font-family: var(--f-lat); direction: ltr; text-align: right; }
.field input:focus, .field select:focus { outline: none; border-bottom-color: var(--green); box-shadow: 0 2px 0 var(--green); }
.dims { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--s2); }
/* the result is engraved on a fan nameplate */
.sel__result { position: relative; padding: var(--s3) var(--s4) var(--s2); background: linear-gradient(160deg, #FBFCFC, #DDE2E4); border: 1px solid #AEB6BA; box-shadow: inset 0 0 0 6px #EEF1F2, inset 0 0 0 7px #C3C9CC; }
.sel__result::before, .sel__result::after { content: ""; position: absolute; top: 12px; width: 9px; height: 9px; border-radius: 50%; background: radial-gradient(circle at 35% 35%, #fff, #9AA3A7 60%, #6F7A7F); }
.sel__result::before { right: 12px; } .sel__result::after { left: 12px; }
.sel__result > p:first-child { font-size: .9rem; color: var(--steel); }
.sel__result .sel__q { color: var(--graphite); font: 200 clamp(2.6rem, 4.6vw, 4rem)/1.1 var(--f-lat); direction: ltr; text-align: right; margin-block: .3rem .2rem; }
.sel__result .sel__q small { font-size: .36em; font-weight: 400; margin-left: .35em; color: var(--steel); }
.sel__result .sel__formula { font: 300 .9rem/1.6 var(--f-lat); direction: ltr; text-align: right; color: var(--green-ink); border-top: 1px solid #B9C0C3; padding-top: .5rem; }
.sel__filters { display: flex; flex-wrap: wrap; gap: .4rem; }
.chipbox { position: relative; }
.chipbox input { position: absolute; opacity: 0; inset: 0; cursor: pointer; }
.chipbox span { display: inline-flex; align-items: center; gap: .45rem; padding: .4rem .8rem; border: 1px solid #A9B1B5; background: #fff; font-size: .88rem; transition: background-color .2s, border-color .2s, color .2s; }
.chipbox span::before { content: ""; width: 4px; height: 1em; background: var(--fc, var(--graphite)); }
.chipbox input:checked + span { border-color: var(--graphite); background: var(--graphite); color: #fff; }
.chipbox input:focus-visible + span { outline: 2px solid var(--green); outline-offset: 2px; }
.sel__summary { display: flex; flex-wrap: wrap; justify-content: space-between; gap: .5rem 1rem; padding-bottom: .8rem; border-bottom: 2px solid var(--graphite); font-size: .95rem; }
.sel__summary b { font-weight: 600; }
.match { display: grid; grid-template-columns: 6.5rem minmax(0, 1fr) auto; gap: .3rem 1.2rem; align-items: center; padding: 1rem 0; border-bottom: 1px solid var(--rule); text-decoration: none; color: inherit; }
.match:hover .match__model { color: var(--green-ink); }
.match__model { display: block; font: 400 1.05rem/1.4 var(--f-lat); direction: ltr; text-align: right; transition: color .2s; }
.match__name { display: block; font-size: .85rem; color: #4C5558; }
.match__spec { display: flex; gap: 1.2rem; font: 400 .82rem/1.5 var(--f-lat); direction: ltr; color: #4C5558; text-align: left; }
.match__spec b { display: block; font-weight: 500; color: var(--graphite); font-size: .95rem; }
.match__bar { grid-column: 2 / -1; height: 3px; background: #DDE2E4; position: relative; }
.match__bar i { position: absolute; inset: 0 auto 0 0; background: var(--fc); width: var(--w, 50%); }
.sel__empty { padding: var(--s5) 0; color: #4C5558; }
.sel__note { margin-top: var(--s3); font-size: .82rem; color: var(--steel); line-height: 1.9; }

/* ---------- trust ---------- */
.trust__slot .lat { font: 200 clamp(2rem, 3.4vw, 3rem)/1.1 var(--f-lat); color: var(--green); display: block; margin-bottom: var(--s2); }
.trust__slot .btn { margin-top: var(--s3); }
.trust__slot .btn--solid:hover { background: #fff; border-color: #fff; color: var(--graphite); }
.proj__img img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.proj__img:has(img)::after { content: none; }

/* =========================================================
   RESPONSIVE
   ========================================================= */
@media (max-width: 1023px) {
  :root { --nav-h: 64px; }
  .nav__links, .nav__cta { display: none; }
  .nav__toggle { display: block; }
  .problem__pin { grid-template-columns: 1fr; gap: var(--s4); }
  .about__grid, .products__head, .apps__head, .projects__head, .contact__grid { grid-template-columns: 1fr; }
  .footer__grid { grid-template-columns: 1fr 1fr; }
  .footer__brand { grid-column: 1 / -1; }

  /* products & applications: compact sticky visual on top, list scrolls beneath */
  .products__grid, .apps__grid { grid-template-columns: 1fr; gap: 0; }
  .products__sheet, .apps__visual { order: 0; top: var(--nav-h); z-index: 3; padding-block: var(--s1); }
  .products__sheet { background: var(--galv); }
  .apps__visual { background: var(--zinc); }
  .sheet { aspect-ratio: auto; height: 40vh; min-height: 240px; }
  .sheet__parts { display: none; }
  .sheet__drawings { margin: var(--s2) var(--s3); }
  .drawing .bal, .drawing .bt, .drawing .ld, .drawing .ldot { display: none; }
  .section-cut { height: 38vh; min-height: 220px; width: 100%; }
  .apps__list, .products__list { order: 1; }
  .family { min-height: 48vh; }
  .problem__steps { gap: var(--s4); }
  .problem__steps .pstep { grid-area: auto; opacity: 1; transform: none; pointer-events: auto; }
  .app { min-height: 30vh; }
}
@media (max-width: 767px) {
  :root { --s7: 4.5rem; --s6: 3rem; }
  .hero { justify-content: flex-start; padding-top: calc(var(--nav-h) + min(50vw, 24vh) + 1.5rem); padding-bottom: var(--s4); }
  .hero__lead { margin-top: var(--s2); }
  .hero__actions { margin-top: var(--s3); gap: .6rem; }
  .hero__actions .btn { padding: .7em 1.1em; font-size: .95rem; }
  .hero__facts { gap: var(--s2); margin-top: var(--s4); }
  .hero__facts b { font-size: 1rem; }
  .hero__facts span { display: none; }
  .hero__cue { display: none; }
  .plate__rows > div { grid-template-columns: 1fr; gap: 0; }
  .problem__steps { gap: var(--s4); }
  .problem__steps .pstep { grid-area: auto; opacity: 1; transform: none; pointer-events: auto; }
  .projects__grid { grid-template-columns: 1fr; }
  .proj--a, .proj--b, .proj--c, .proj--d, .proj--e { grid-column: auto; grid-row: auto; }
  .proj--a .proj__img { height: auto; min-height: 0; aspect-ratio: 4 / 3; }
  .trust { grid-template-columns: 1fr; }
  .sel, .selector__head { grid-template-columns: minmax(0, 1fr); }
  .sel__form { position: static; }
  .match { grid-template-columns: 6rem minmax(0, 1fr); }
  .match__spec { grid-column: 1 / -1; justify-content: flex-start; }
  .footer__grid { grid-template-columns: 1fr; }
  .footer__base { flex-direction: column; gap: .3rem; }
  .form { padding: var(--s3); }
  .sheet__title { grid-template-columns: 1fr auto; }
  .sheet__title > span:nth-child(3), .sheet__mark { display: none; }
  .sheet__parts { display: none; }
  .sheet__drawings { margin: var(--s2); }
}

/* ---------- Reduced motion: everything visible, no cinematic sequences ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .about__statement .w { opacity: 1 !important; }
  .pstep { position: static; opacity: 1 !important; transform: none !important; pointer-events: auto !important; }
  .problem__steps { gap: var(--s4); }
  .problem__steps .pstep { grid-area: auto; }
  .duct__fill { transform: none !important; }
  .station .station__no { color: var(--green); -webkit-text-stroke-color: var(--green); }
  .gauge__bar i { background: var(--green); transform: none; }
}