:root {
  --ink: #101820;
  --ink-deep: #091016;
  --ink-soft: #1d2a34;
  --paper: #edf1f1;
  --paper-warm: #f4f2ed;
  --text: #17212a;
  --muted: #5d6870;
  --hot: #b83b08;
  --hot-bright: #ff7a24;
  --cool: #0b6178;
  --cool-bright: #5bc9df;
  --line: rgba(16, 24, 32, .18);
  --line-dark: rgba(255, 255, 255, .18);
  --header: 78px;
  --max: 1320px;
  --journey-progress: 0;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: var(--header); }
body {
  margin: 0;
  color: var(--text);
  background: var(--paper);
  font-family: "Bahnschrift", "Microsoft YaHei UI", "PingFang SC", sans-serif;
  line-height: 1.65;
  overflow-x: hidden;
  text-rendering: optimizeLegibility;
  caret-color: var(--hot);
  scrollbar-color: var(--hot) var(--ink);
}
body.menu-open { overflow: hidden; }
img { display: block; width: 100%; height: auto; }
a { color: inherit; text-underline-offset: .2em; }
button, input, select, textarea { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
:focus-visible { outline: 3px solid var(--hot-bright); outline-offset: 4px; }
::selection { color: #fff; background: var(--hot); }
::-webkit-scrollbar { width: 12px; height: 12px; }
::-webkit-scrollbar-track { background: var(--ink); }
::-webkit-scrollbar-thumb { background: var(--hot); border: 3px solid var(--ink); }

.skip-link { position: fixed; z-index: 1000; left: 16px; top: 10px; transform: translateY(-180%); color: #fff; background: var(--hot); padding: 10px 16px; }
.skip-link:focus { transform: translateY(0); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
  padding: 0 max(28px, calc((100vw - var(--max)) / 2));
  color: #fff;
  background: rgba(9, 16, 22, .94);
  border-bottom: 1px solid var(--line-dark);
  backdrop-filter: blur(14px);
}
.site-brand, .footer-brand { min-height: 48px; display: inline-flex; align-items: center; gap: 13px; text-decoration: none; }
.brand-mark { width: 44px; height: 38px; fill: none; stroke: var(--hot-bright); stroke-width: 1.8; }
.brand-mark .brand-flow { stroke: var(--cool-bright); }
.site-brand span { display: grid; gap: 1px; }
.site-brand strong { font-size: 14px; letter-spacing: .03em; }
.site-brand small { color: rgba(255,255,255,.54); font-size: 8px; letter-spacing: .16em; }
.site-nav { display: flex; align-items: center; gap: clamp(14px, 1.8vw, 30px); }
.site-nav a { min-height: 44px; display: grid; place-items: center; color: rgba(255,255,255,.7); font-size: 13px; text-decoration: none; }
.site-nav a:hover { color: var(--hot-bright); }
.site-nav .nav-contact { padding-inline: 19px; color: #fff; background: var(--hot); }
.site-nav .nav-contact:hover { color: #fff; background: #b93e0a; }
.menu-toggle { display: none; }

.hero { min-height: calc(100svh - var(--header)); max-width: 1800px; margin: auto; position: relative; color: #fff; background: var(--ink-deep); overflow: hidden; }
.hero-media, .hero-media img { position: absolute; inset: 0; width: 100%; height: 100%; margin: 0; }
.hero-media img { object-fit: cover; object-position: center; }
.hero-shade { position: absolute; inset: 0; background: linear-gradient(90deg, rgba(5,10,14,.93) 0 40%, rgba(5,10,14,.48) 64%, rgba(5,10,14,.14)), linear-gradient(0deg, rgba(5,10,14,.78), transparent 40%); }
.hero-copy { position: relative; z-index: 2; max-width: var(--max); min-height: calc(100svh - var(--header)); margin: auto; padding: clamp(90px, 12vh, 150px) 0 180px; display: flex; flex-direction: column; justify-content: center; align-items: flex-start; }
.hero-location, .section-register, .form-title { margin: 0; color: var(--hot-bright); font-size: 11px; font-weight: 700; letter-spacing: .16em; text-transform: uppercase; }
.hero h1, h2, h3 { margin: 0; line-height: 1; letter-spacing: -.04em; }
.hero h1 { max-width: 900px; font-size: clamp(54px, 6.5vw, 108px); }
.hero h1 em { display: inline-block; color: var(--paper); font-style: normal; }
.hero-location { margin-top: 26px; }
.hero-lead { max-width: 660px; margin: 36px 0 0; color: rgba(255,255,255,.7); font-size: clamp(16px, 1.35vw, 20px); }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 40px; }
.button { min-height: 48px; display: inline-flex; align-items: center; justify-content: center; padding: 12px 23px; border: 1px solid currentColor; border-radius: 0; cursor: pointer; font-weight: 700; text-decoration: none; }
.button-hot { color: #fff; background: var(--hot); border-color: var(--hot); }
.button-hot:hover { background: #8f2d05; border-color: #8f2d05; }
.button-ghost { color: #fff; background: transparent; border-color: rgba(255,255,255,.54); }
.button-ghost:hover { color: var(--hot-bright); border-color: var(--hot-bright); }
.hero-register { position: absolute; z-index: 3; inset: auto 0 0; margin: 0; display: grid; grid-template-columns: repeat(3, 1fr); background: rgba(9,16,22,.9); border-top: 1px solid var(--line-dark); }
.hero-register div { min-height: 126px; padding: 28px max(28px, calc((100vw - var(--max)) / 6)); border-right: 1px solid var(--line-dark); display: grid; align-content: center; gap: 5px; }
.hero-register div:last-child { border-right: 0; }
.hero-register dt { color: var(--cool-bright); font-size: 10px; letter-spacing: .13em; }
.hero-register dd { margin: 0; font-size: 14px; }
.flow-line { position: absolute; z-index: 2; pointer-events: none; }
.flow-line-hero { left: 0; right: 0; bottom: 126px; height: 2px; background: linear-gradient(90deg, var(--hot), var(--hot-bright) 55%, var(--cool-bright)); }
.flow-line-hero span { position: absolute; left: 61%; top: 50%; width: 10px; height: 10px; border: 2px solid var(--cool-bright); border-radius: 50%; transform: translate(-50%,-50%); background: var(--ink); }

.material { display: grid; grid-template-columns: .82fr 1.18fr; min-height: 760px; background: var(--paper-warm); }
.material-copy { padding: clamp(80px, 9vw, 150px); display: flex; flex-direction: column; justify-content: center; }
h2 { font-size: clamp(44px, 5vw, 82px); }
.section-register { margin-top: 24px; color: var(--hot); }
.material-copy > p:not(.section-register) { max-width: 610px; margin: 34px 0 0; color: var(--muted); }
.material-boundary { margin: 48px 0 0; border-top: 1px solid var(--line); }
.material-boundary div { display: grid; grid-template-columns: 90px 1fr; gap: 20px; padding: 18px 0; border-bottom: 1px solid var(--line); }
.material-boundary dt { color: var(--hot); font-size: 12px; font-weight: 700; }
.material-boundary dd { margin: 0; }
.material-media { margin: 0; overflow: hidden; background: #111; }
.material-media img { height: 100%; object-fit: cover; }

.process { position: relative; color: #fff; background: var(--ink); }
.process-intro { min-height: 590px; max-width: var(--max); margin: auto; padding: 120px 0; display: grid; grid-template-columns: 1fr .7fr; align-content: center; gap: 0 80px; }
.process-intro h2 { grid-row: 1 / 4; }
.process-intro .section-register { align-self: end; color: var(--hot-bright); }
.process-intro > p:last-child { margin: 26px 0 0; color: rgba(255,255,255,.62); }
.process-journey { position: relative; max-width: 1600px; margin: auto; padding-bottom: 1px; }
.journey-rail { position: absolute; z-index: 4; top: 0; bottom: 0; left: 50%; width: 1px; background: var(--line-dark); }
.journey-rail span { position: absolute; inset: 0; transform: scaleY(var(--journey-progress)); transform-origin: top; background: linear-gradient(var(--hot-bright), var(--hot), var(--cool-bright)); }
.journey-rail i { position: sticky; top: 50vh; display: block; width: 13px; height: 13px; margin-left: -6px; border: 2px solid var(--hot-bright); background: var(--ink); transform: rotate(45deg); }
.journey-step { min-height: 720px; display: grid; grid-template-columns: 1fr 1fr; border-top: 1px solid var(--line-dark); }
.journey-step figure { margin: 0; overflow: hidden; }
.journey-step figure img { height: 100%; object-fit: cover; }
.journey-copy { padding: clamp(80px, 9vw, 150px); display: flex; flex-direction: column; justify-content: center; }
.step-no { color: var(--hot-bright); font-size: 12px; letter-spacing: .16em; }
.journey-copy h3 { margin-top: 22px; font-size: clamp(44px, 5.6vw, 88px); }
.journey-copy p { max-width: 560px; margin: 30px 0 0; color: rgba(255,255,255,.62); }
.finish-step .journey-copy { background: var(--ink-soft); }

.upgrade { min-height: 650px; max-width: var(--max); margin: auto; display: grid; grid-template-columns: 1fr .72fr .2fr; align-items: center; position: relative; }
.upgrade-title { padding-right: 80px; }
.upgrade-copy { padding: 70px; border-left: 1px solid var(--line); }
.upgrade-copy p { margin: 0 0 22px; color: var(--muted); }
.text-link { min-height: 44px; display: inline-flex; align-items: center; gap: 12px; margin-top: 10px; border-bottom: 1px solid currentColor; color: var(--hot); font-weight: 700; text-decoration: none; }
.text-link:hover { color: #852b05; }
.upgrade-axis { align-self: stretch; position: relative; display: flex; flex-direction: column; justify-content: center; align-items: center; }
.upgrade-axis::before { content: ""; position: absolute; inset: 0 auto; width: 1px; background: var(--line); }
.upgrade-axis span { position: relative; width: 10px; height: 10px; margin: 60px 0; border-radius: 50%; background: var(--hot); }
.upgrade-axis span:last-child { background: var(--cool); }
.upgrade-axis i { position: relative; width: 34px; height: 1px; background: var(--text); }

.energy { min-height: 800px; display: grid; grid-template-columns: .9fr 1.1fr; position: relative; color: #fff; background: #071724; }
.energy-copy { padding: clamp(90px, 9vw, 150px); display: flex; flex-direction: column; justify-content: center; }
.energy-copy h2 em { color: var(--cool-bright); font-style: normal; }
.energy-copy .section-register { color: var(--cool-bright); }
.energy-copy > p:not(.section-register) { margin: 32px 0 0; color: rgba(255,255,255,.64); }
.energy-path { margin: 50px 0 0; padding: 0; list-style: none; border-top: 1px solid var(--line-dark); }
.energy-path li { padding: 18px 0; display: grid; grid-template-columns: 110px 1fr; gap: 24px; border-bottom: 1px solid var(--line-dark); }
.energy-path b { color: var(--cool-bright); }
.energy-path span { color: rgba(255,255,255,.66); font-size: 14px; }
.energy-media { margin: 0; overflow: hidden; }
.energy-media img { height: 100%; object-fit: cover; }
.flow-line-energy { left: 0; bottom: 0; width: 100%; height: 2px; background: linear-gradient(90deg, var(--hot), var(--cool-bright) 58%); }

.green { min-height: 780px; display: grid; grid-template-columns: 1.12fr .88fr; background: #dfe9e8; }
.green-media { margin: 0; overflow: hidden; position: relative; }
.green-media::after { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, transparent 65%, rgba(223,233,232,.85)); }
.green-media img { height: 100%; object-fit: cover; }
.green-copy { padding: clamp(80px, 8vw, 135px); align-self: center; }
.green-copy .section-register { color: var(--cool); }
.green-record { display: grid; grid-template-columns: 90px 1fr; gap: 26px; margin-top: 50px; padding: 26px 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.green-record time { color: var(--cool); font-size: 30px; font-weight: 700; }
.green-record p { margin: 0; display: grid; gap: 8px; }
.green-record span, .boundary-note { color: var(--muted); font-size: 13px; }
.boundary-note { margin: 24px 0 0; }
.green .text-link { color: var(--cool); }
.green .text-link:hover { color: #0b5468; }

.location { min-height: 510px; max-width: var(--max); margin: auto; display: grid; grid-template-columns: 1.1fr .62fr .58fr; gap: 70px; align-items: center; }
.location address { padding: 56px 0; border-block: 1px solid var(--line); color: var(--hot); font-size: clamp(22px, 2.4vw, 36px); font-style: normal; font-weight: 700; line-height: 1.4; }
.location > p { color: var(--muted); }

.contact { display: grid; grid-template-columns: 1.08fr .92fr; color: #fff; background: var(--ink); }
.contact-copy { padding: clamp(90px, 9vw, 150px) clamp(36px, 7vw, 120px); }
.contact-copy > p:not(.section-register) { max-width: 650px; margin: 32px 0 0; color: rgba(255,255,255,.64); }
.contact-checklist { margin: 54px 0 0; padding: 0; list-style: none; border-top: 1px solid var(--line-dark); }
.contact-checklist li { min-height: 70px; display: flex; align-items: center; gap: 14px; border-bottom: 1px solid var(--line-dark); }
.contact-checklist li::before { content: ""; width: 8px; height: 8px; transform: rotate(45deg); background: var(--hot-bright); }
.contact-form { padding: clamp(80px, 8vw, 130px); display: flex; flex-direction: column; justify-content: center; color: var(--text); background: var(--paper-warm); }
.form-title { color: var(--hot); margin-bottom: 28px; }
.contact-form label { margin: 18px 0 8px; font-size: 12px; letter-spacing: .08em; }
.contact-form input, .contact-form select, .contact-form textarea { width: 100%; min-height: 48px; padding: 12px 2px; color: var(--text); background: transparent; border: 0; border-bottom: 1px solid var(--text); border-radius: 0; }
.contact-form textarea { padding: 14px; border: 1px solid var(--text); resize: vertical; }
.contact-form .button { align-self: flex-start; margin-top: 28px; }
.form-status { min-height: 28px; margin: 18px 0 0; color: #a93505; font-size: 13px; font-weight: 700; }

.site-footer { min-height: 180px; max-width: 1800px; margin: auto; padding: 44px max(28px, calc((100vw - var(--max)) / 2)); display: flex; align-items: center; justify-content: space-between; gap: 36px; background: var(--paper-warm); border-top: 1px solid var(--line); }
.footer-brand { font-weight: 700; }
.footer-meta { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 16px 30px; color: var(--muted); font-size: 11px; }
.footer-meta p { margin: 0; }
.creative-note { color: var(--text); }

@media (max-width: 1120px) {
  .hero-copy, .process-intro { padding-inline: 40px; }
  .site-nav { gap: 12px; }
  .material-copy, .journey-copy, .energy-copy, .green-copy, .contact-form { padding: 70px 54px; }
  .upgrade, .location { padding-inline: 40px; }
  .upgrade-copy { padding: 50px; }
}

@media (max-width: 820px) {
  :root { --header: 68px; }
  .site-header { padding: 0 20px; backdrop-filter: none; }
  .site-brand strong { font-size: 12px; }
  .site-brand small { display: none; }
  .brand-mark { width: 38px; }
  .menu-toggle { min-width: 72px; min-height: 44px; padding: 0; display: inline-flex; align-items: center; justify-content: center; gap: 10px; color: #fff; background: transparent; border: 0; cursor: pointer; }
  .menu-toggle span { font-size: 13px; font-weight: 700; }
  .menu-toggle i, .menu-toggle i::before { display: block; width: 20px; height: 1px; background: currentColor; transition: transform .2s ease; }
  .menu-toggle i { position: relative; }
  .menu-toggle i::before { content: ""; position: absolute; top: 6px; }
  .menu-toggle[aria-expanded="true"] i { transform: rotate(45deg); }
  .menu-toggle[aria-expanded="true"] i::before { top: 0; transform: rotate(90deg); }
  .site-nav { position: fixed; z-index: 90; left: 0; right: 0; top: var(--header); height: calc(100dvh - var(--header)); padding: 28px 24px 36px; display: flex; flex-direction: column; align-items: stretch; gap: 0; overflow-y: auto; color: #fff; background: rgba(9,16,22,.99); transform: translateX(100%); visibility: hidden; transition: transform .24s ease, visibility 0s linear .24s; }
  .menu-toggle[aria-expanded="true"] + .site-nav { transform: translateX(0); visibility: visible; transition: transform .24s ease; }
  .site-nav a { min-height: 64px; display: flex; justify-content: flex-start; color: #fff; font-size: 24px; font-weight: 700; border-bottom: 1px solid var(--line-dark); }
  .site-nav .nav-contact { margin-top: 20px; justify-content: center; background: var(--hot); }

  .hero { min-height: 900px; }
  .hero-media img { object-position: 64% center; }
  .hero-shade { background: linear-gradient(0deg, rgba(5,10,14,.94) 0 52%, rgba(5,10,14,.35)); }
  .hero-copy { min-height: 720px; padding: 90px 24px 150px; justify-content: flex-end; }
  .hero h1 { font-size: clamp(48px, 13vw, 72px); }
  .hero-register { grid-template-columns: 1fr; }
  .hero-register div { min-height: 82px; padding: 16px 24px; border-right: 0; border-bottom: 1px solid var(--line-dark); }
  .hero-register div:last-child { border-bottom: 0; }
  .flow-line-hero { bottom: 246px; }

  .material, .energy, .green, .contact { grid-template-columns: 1fr; }
  .material-copy, .energy-copy, .green-copy, .contact-copy, .contact-form { padding: 84px 24px; }
  .material-media { min-height: 520px; }
  .process-intro { min-height: auto; padding: 100px 24px; display: block; }
  .process-intro .section-register { margin-top: 24px; }
  .process-intro > p:last-child { max-width: 570px; }
  .journey-rail { left: 18px; }
  .journey-step { min-height: auto; grid-template-columns: 1fr; padding-left: 36px; }
  .journey-copy { padding: 70px 24px; }
  .journey-step figure { min-height: 420px; }
  .furnace-step figure, .finish-step figure { order: 2; }
  .furnace-step .journey-copy, .finish-step .journey-copy { order: 1; }

  .upgrade { min-height: auto; padding: 90px 24px; grid-template-columns: 1fr; }
  .upgrade-title { padding: 0; }
  .upgrade-copy { margin-top: 54px; padding: 54px 0 0; border-left: 0; border-top: 1px solid var(--line); }
  .upgrade-axis { display: none; }
  .energy-media { min-height: 500px; }
  .green-media { min-height: 450px; }
  .green-media::after { background: linear-gradient(0deg, rgba(223,233,232,.6), transparent 52%); }

  .location { min-height: auto; padding: 90px 24px; grid-template-columns: 1fr; gap: 36px; }
  .location address { padding: 34px 0; }
  .contact-form { order: 2; }
  .site-footer { padding: 50px 24px; flex-direction: column; align-items: flex-start; }
  .footer-meta { justify-content: flex-start; }
}

@media (max-width: 480px) {
  .hero-actions { width: 100%; }
  .hero-actions .button { width: 100%; }
  h2 { font-size: clamp(40px, 11.5vw, 56px); }
  .material-media, .journey-step figure, .energy-media, .green-media { min-height: 360px; }
  .material-boundary div, .energy-path li { grid-template-columns: 1fr; gap: 6px; }
  .green-record { grid-template-columns: 70px 1fr; gap: 14px; }
  .green-record time { font-size: 24px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .menu-toggle i, .menu-toggle i::before, .site-nav { transition: none; }
  .journey-rail span { transform: scaleY(1); }
}