:root,
html[data-theme="light"] {
  --navy: #0b1f33;
  --copper: #b87333;
  --paper: #f4f1ea;
  --white: #ffffff;
  --ink: #1c1c1c;
  --slate: #5c6570;
  --line: #d8d2c6;
  --hero-fg: #f4f1ea;
  --hero-muted: #d7d1c6;
  --header-fg: #f4f1ea;
  --max: 1120px;
}

html[data-theme="dark"] {
  --navy: #07141f;
  --copper: #c8894a;
  --paper: #0e1822;
  --white: #152231;
  --ink: #e8e4dc;
  --slate: #a3abb4;
  --line: #2a3a4a;
  --hero-fg: #f4f1ea;
  --hero-muted: #c9c2b4;
  --header-fg: #f4f1ea;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: "IBM Plex Sans", "Noto Sans SC", sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.55;
  transition: background-color 0.2s ease, color 0.2s ease;
}
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; }
img { max-width: 100%; display: block; }

.wrap { width: min(var(--max), calc(100% - 40px)); margin: 0 auto; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--navy);
  color: var(--header-fg);
  height: 72px;
}
.site-header.scrolled {
  background: var(--white);
  color: var(--ink);
  border-bottom: 1px solid var(--line);
}
.header-inner, .nav, .header-right {
  display: flex;
  align-items: center;
  gap: 18px;
}
.header-inner { height: 72px; justify-content: space-between; }
.logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: "Outfit", "Noto Sans SC", sans-serif;
  font-weight: 800;
  letter-spacing: -0.02em;
  font-size: 15px;
  color: inherit;
}
.logo-mark {
  width: 36px;
  height: 36px;
  object-fit: contain;
  flex-shrink: 0;
  border-radius: 50%;
}
.logo-text {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  justify-content: center;
  gap: 1px;
  width: max-content;
  line-height: 1;
  text-align: left;
}
.logo-word,
.logo-group {
  display: block;
  margin: 0;
  padding: 0;
  border: 0;
  font-family: inherit;
  white-space: nowrap;
}
.logo-word {
  position: relative;
  width: max-content;
  height: 36px;
  font-size: 24px;
  font-weight: 800;
  line-height: 36px;
  letter-spacing: -0.02em;
  text-transform: uppercase;
}
.logo-word .logo-tm {
  position: absolute;
  left: 100%;
  top: 0.12em;
  margin-left: 0.04em;
  font-size: 0.48em;
  font-weight: 800;
  letter-spacing: 0;
  line-height: 1;
  text-transform: none;
}
.logo-group {
  width: 100%;
  letter-spacing: 0;
  text-align: justify;
  text-align-last: justify;
}
.logo-group-only {
  width: auto;
  height: 36px;
  font-family: "Noto Sans SC", "Outfit", sans-serif;
  font-size: 24px;
  font-weight: 700;
  line-height: 36px;
  letter-spacing: 0.08em;
  text-align: left;
  text-align-last: auto;
}
.nav a { font-size: 13px; letter-spacing: 0.04em; opacity: 0.88; }
.nav a:hover, .nav a.active { opacity: 1; color: var(--copper); }
.lang {
  display: inline-flex;
  align-items: center;
  gap: 2px;
}
.lang a {
  font-size: 12px;
  margin: 0 4px;
  min-width: 1.5em;
  text-align: center;
  line-height: 1.2;
}
.lang a.active { color: var(--copper); font-weight: 600; }
.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 36px;
  padding: 0 10px;
  border: 1px solid currentColor;
  background: transparent;
  color: inherit;
  cursor: pointer;
  font-size: 12px;
  letter-spacing: 0.04em;
  opacity: 0.92;
}
.theme-toggle:hover { color: var(--copper); border-color: var(--copper); }
.theme-toggle-icon { font-size: 14px; line-height: 1; }
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 18px;
  border: 1px solid transparent;
  cursor: pointer;
  letter-spacing: 0.04em;
  font-size: 13px;
  font-weight: 600;
}
.btn-primary { background: var(--copper); color: #fff; }
.btn-ghost { background: transparent; border-color: currentColor; }
.btn-dark { background: var(--navy); color: var(--hero-fg); }
html[data-theme="dark"] .btn-dark { border: 1px solid var(--line); }
.nav-toggle { display: none; background: none; border: 0; color: inherit; }

.hero {
  color: var(--hero-fg);
  min-height: calc(100vh - 72px);
  display: flex;
  align-items: flex-end;
  position: relative;
  overflow: hidden;
  background:
    linear-gradient(
      105deg,
      rgba(12, 18, 32, 0.96) 0%,
      rgba(12, 18, 32, 0.88) 38%,
      rgba(12, 18, 32, 0.45) 62%,
      rgba(12, 18, 32, 0.55) 100%
    ),
    url("/assets/hero-global.jpg?v=2") 58% center / cover no-repeat;
}
.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(ellipse at 78% 42%, rgba(184, 115, 51, 0.22), transparent 42%),
    linear-gradient(to top, rgba(12, 18, 32, 0.55), transparent 40%);
}
.hero-copy { position: relative; z-index: 1; width: min(var(--max), calc(100% - 40px)); margin: 0 auto; padding: 72px 0 56px; }
.hero-brand {
  margin: 0 0 18px;
  line-height: 0;
}
.hero-wordmark {
  display: block;
  width: min(100%, 28rem);
  height: auto;
  mix-blend-mode: screen;
}
.eyebrow { color: var(--copper); letter-spacing: 0.16em; font-size: 12px; font-weight: 600; margin: 0 0 14px; }
.hero-title {
  display: grid;
  gap: 0.08em;
  margin: 0 0 16px;
  font-size: clamp(28px, 3.6vw, 42px);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.12;
  max-width: none;
}
.hero-line { display: block; white-space: nowrap; }
.hero p.lead { max-width: 42ch; margin: 0; color: var(--hero-muted); font-size: clamp(15px, 1.2vw, 17px); line-height: 1.5; }
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; margin: 22px 0 28px; }
.hero-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--hero-muted);
  max-width: 52rem;
}
.hero-links a { border-bottom: 1px solid var(--copper); padding-bottom: 2px; }
.hero-links a:hover { color: var(--hero-fg); }

section { padding: 72px 0; }
.section-h { margin: 0 0 28px; }
.section-h h2 { margin: 8px 0 0; font-size: 32px; line-height: 1.2; }
.grid-3, .grid-4, .grid-8 { display: grid; gap: 16px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-8 { grid-template-columns: repeat(4, 1fr); }
.card {
  background: var(--white);
  border: 1px solid var(--line);
  padding: 22px;
  min-height: 150px;
}
.card.live { border-color: var(--copper); }
.card h3 { margin: 0 0 8px; font-size: 18px; }
.card p, .muted { color: var(--slate); }
.family-card { min-height: 0; }
.family-card h3 { margin: 0 0 4px; }
.family-card h3 a { color: inherit; }
.family-card h3 a:hover { color: var(--copper); }
.line-list {
  list-style: none;
  margin: 12px 0 0;
  padding: 0;
}
.line-list li + li { border-top: 1px solid var(--line); }
.line-list a {
  display: block;
  padding: 9px 0;
  font-size: 14px;
  color: var(--ink);
}
.line-list a:hover { color: var(--copper); }
.badge {
  display: inline-block;
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--copper);
  margin-bottom: 10px;
}
.facts { display: grid; grid-template-columns: 1.4fr 1fr; gap: 40px; align-items: start; }
.fact { border-top: 1px solid var(--line); padding: 14px 0; }
.steps {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 16px;
  align-items: start;
}
.step {
  display: grid;
  grid-template-columns: 1fr;
  justify-items: start;
  gap: 10px;
}
.step > div {
  font-size: 14px;
  line-height: 1.4;
}
.n {
  width: 32px; height: 32px;
  border: 1px solid var(--copper);
  color: var(--copper);
  display: grid; place-items: center;
  font-size: 12px;
}
form.rfq { display: grid; gap: 12px; max-width: 560px; }
label { font-size: 13px; color: var(--slate); display: grid; gap: 6px; }
input, select, textarea {
  border: 1px solid var(--line);
  background: var(--white);
  padding: 10px 12px;
  color: var(--ink);
}
textarea { min-height: 96px; resize: vertical; }
.ok { color: #2c6a3f; }
.err { color: #8a2b2b; }
html[data-theme="dark"] .ok { color: #6fbf86; }
html[data-theme="dark"] .err { color: #e08a8a; }
.note { font-size: 13px; color: var(--slate); border-left: 3px solid var(--copper); padding-left: 12px; }
.cta-band { background: var(--navy); color: var(--hero-fg); }
.cta-band h2 { margin-top: 0; }
.cta-row { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 20px; }
footer {
  background: var(--navy);
  color: var(--hero-muted);
  padding: 48px 0 28px;
  font-size: 13px;
}
.foot-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr auto;
  gap: 24px;
  align-items: end;
}
.foot-copy {
  white-space: nowrap;
  text-align: right;
  line-height: 1.4;
  align-self: end;
  justify-self: end;
}

/* Recycled metals — HVAC-style layout (aligned with copper product site) */
.hvac-hero {
  position: relative;
  min-height: min(88vh, 52rem);
  display: grid;
  align-items: end;
  overflow: hidden;
  color: #f4f6f8;
}
.hvac-hero-media {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(115deg, rgba(11, 31, 51, 0.82) 0%, rgba(11, 31, 51, 0.45) 48%, rgba(11, 31, 51, 0.72) 100%),
    var(--hvac-bg) center / cover no-repeat;
}
.hvac-hero-shade {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 72% 38%, rgba(184, 115, 51, 0.28), transparent 42%),
    linear-gradient(to top, rgba(11, 31, 51, 0.85), transparent 55%);
}
.hvac-hero-copy {
  position: relative;
  z-index: 1;
  width: min(var(--max), calc(100% - 40px));
  margin: 0 auto;
  padding: 72px 0 56px;
  max-width: 40rem;
}
.hvac-brand {
  margin: 0 0 14px;
  letter-spacing: 0.12em;
  font-size: 12px;
  font-weight: 600;
  color: var(--copper);
}
.hvac-brand\sup { font-size: 0.7em; }
.hvac-hero-copy h1 {
  margin: 0;
  display: grid;
  gap: 0.25rem;
  font-size: clamp(1.45rem, 3.2vw, 2.1rem);
  line-height: 1.25;
  font-weight: 700;
}
.hvac-line { display: block; }
.hvac-points {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 8px;
}
.hvac-points li {
  padding-left: 1.1em;
  position: relative;
  color: var(--hero-muted);
  font-size: 15px;
}
.hvac-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--copper);
}
.hvac-crumb {
  margin-top: 28px;
  font-size: 13px;
  color: var(--hero-muted);
}
.hvac-crumb a { color: var(--hero-fg); border-bottom: 1px solid var(--copper); }
.hvac-cap,
.hvac-quote {
  padding: 72px 0;
}
.hvac-cap h2,
.hvac-quote h2 {
  margin: 8px 0 14px;
  font-size: clamp(26px, 3vw, 34px);
  line-height: 1.2;
  max-width: 22ch;
}
.section-lead {
  color: var(--slate);
  max-width: 54ch;
  margin: 0 0 28px;
}
.promise-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}
.promise-list li {
  border: 1px solid var(--line);
  background: var(--white);
  padding: 18px 16px;
  display: grid;
  gap: 6px;
}
.promise-list strong { font-size: 16px; }
.promise-list span { color: var(--slate); font-size: 14px; }
.hvac-quote {
  background: var(--white);
  border-top: 1px solid var(--line);
}
.rfq-recycled { max-width: 720px; margin-top: 8px; }
.rfq-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 12px;
}
.rfq-grid .span-2 { grid-column: 1 / -1; }
@media (max-width: 720px) {
  .promise-list,
  .rfq-grid { grid-template-columns: 1fr; }
  .rfq-grid .span-2 { grid-column: auto; }
}

footer a { color: var(--hero-fg); }
footer strong { color: var(--hero-fg); display: block; margin-bottom: 10px; }
.crumb { font-size: 13px; color: var(--slate); margin: 28px 0 8px; }
.page-hero h1 { font-size: 40px; margin: 8px 0 12px; }
.page-hero-media {
  position: relative;
  color: var(--hero-fg);
  min-height: min(640px, calc(100vh - 72px));
  display: flex;
  align-items: flex-end;
  overflow: hidden;
  background:
    linear-gradient(
      105deg,
      rgba(12, 18, 32, 0.96) 0%,
      rgba(12, 18, 32, 0.88) 38%,
      rgba(12, 18, 32, 0.45) 62%,
      rgba(12, 18, 32, 0.55) 100%
    ),
    url("/assets/hero-global.jpg?v=2") 58% center / cover no-repeat;
  background-color: var(--navy);
  padding: 0 0 48px;
}
.page-hero-media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(ellipse at 78% 42%, rgba(184, 115, 51, 0.22), transparent 42%),
    linear-gradient(to top, rgba(12, 18, 32, 0.55), transparent 40%);
}
.page-hero-media .wrap {
  position: relative;
  z-index: 1;
  width: min(var(--max), calc(100% - 40px));
  margin: 0 auto;
}
.page-hero-media .crumb { color: var(--hero-muted); margin-top: 36px; }
.page-hero-media .eyebrow { color: var(--copper); }
.page-hero-media h1 { color: var(--hero-fg); margin: 8px 0 12px; }
.page-hero-media p { max-width: 48ch; color: var(--hero-muted); margin: 0; }

/* BUSINESS page — 与首页同一套背景构图；高度贴近首页，避免矮区 cover 左右裁切过头 */
.biz-hero {
  position: relative;
  color: var(--hero-fg);
  min-height: calc(100vh - 72px);
  display: flex;
  align-items: flex-end;
  overflow: hidden;
  background:
    linear-gradient(
      105deg,
      rgba(12, 18, 32, 0.96) 0%,
      rgba(12, 18, 32, 0.88) 38%,
      rgba(12, 18, 32, 0.45) 62%,
      rgba(12, 18, 32, 0.55) 100%
    ),
    url("/assets/hero-global.jpg?v=2") 58% center / cover no-repeat;
  background-color: var(--navy);
  padding: 0 0 56px;
}
.biz-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(ellipse at 78% 42%, rgba(184, 115, 51, 0.22), transparent 42%),
    linear-gradient(to top, rgba(12, 18, 32, 0.55), transparent 40%);
}
.biz-hero .wrap {
  position: relative;
  z-index: 1;
}
.biz-hero .crumb { color: var(--hero-muted); margin-top: 36px; }
.biz-hero .lead { max-width: 44ch; color: var(--hero-muted); margin: 0; }
.biz-hero-title {
  display: grid;
  gap: 0.06em;
  margin: 0 0 14px;
  font-size: clamp(28px, 3.4vw, 40px);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.12;
}
.biz-our-body {
  max-width: 62ch;
  margin: 0 0 28px;
  font-size: 18px;
  line-height: 1.45;
}
.biz-section-lead {
  margin: 8px 0 0;
  font-size: 22px;
  line-height: 1.3;
  font-weight: 500;
}
.biz-pillars .card { min-height: 120px; }
.biz-metals-feature {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 28px;
  min-height: 200px;
  padding: 32px;
}
.biz-metals-feature h3 { margin: 0 0 16px; font-size: 28px; line-height: 1.2; }
.biz-metal-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 6px;
  font-size: 15px;
}
.grid-5 {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
}
.grid-6 {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 16px;
}
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.biz-eco-card { min-height: 120px; }
.biz-coming-card {
  min-height: 150px;
  border-style: dashed;
  opacity: 0.92;
}
.biz-coming-card:hover { opacity: 1; border-color: var(--slate); }
.biz-card-cta {
  display: inline-block;
  margin-top: 12px;
  font-size: 13px;
  color: var(--copper);
  font-weight: 600;
}
.biz-cap-card { min-height: 180px; }
.biz-inquiry-sub { color: var(--hero-muted); max-width: 40ch; margin: 0 0 18px; }
.biz-footnote { padding-top: 0; padding-bottom: 48px; }
.insights-lead { max-width: 52ch; margin: 12px 0 0; color: var(--slate); }
.insights-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 16px;
}
.insights-card .note { margin-top: 16px; font-size: 12px; }
.insights-foot { margin-top: 32px; }

@media (max-width: 1100px) {
  .grid-5 { grid-template-columns: repeat(3, 1fr); }
  .grid-6 { grid-template-columns: repeat(3, 1fr); }
  .steps { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}
@media (max-width: 900px) {
  .grid-5, .grid-6, .grid-2 { grid-template-columns: 1fr; }
  .steps { grid-template-columns: 1fr; }
  .step { grid-template-columns: 32px 1fr; align-items: center; }
  .biz-hero,
  .page-hero-media { min-height: auto; padding-bottom: 36px; }
  .biz-metals-feature { min-height: 0; }
}

@media (max-width: 900px) {
  .nav, .header-right .btn { display: none; }
  .nav.open, .nav-toggle { display: flex; }
  .nav.open {
    position: absolute; left: 0; right: 0; top: 72px;
    background: var(--navy); color: var(--header-fg);
    flex-direction: column; padding: 16px 20px 24px;
  }
  .site-header.scrolled .nav.open { background: var(--white); color: var(--ink); }
  .grid-3, .grid-4, .grid-8, .facts, .foot-grid { grid-template-columns: 1fr; }
  .foot-copy {
    white-space: normal;
    text-align: left;
    justify-self: start;
  }
  .hero {
    min-height: auto;
    background:
      linear-gradient(
        180deg,
        rgba(12, 18, 32, 0.92) 0%,
        rgba(12, 18, 32, 0.78) 55%,
        rgba(12, 18, 32, 0.88) 100%
      ),
      url("/assets/hero-global.jpg?v=2") 58% center / cover no-repeat;
  }
  .hero-line { white-space: normal; }
  .hero-title { font-size: clamp(26px, 7vw, 36px); }
  .theme-toggle-label { display: none; }
  .lang {
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2px;
    line-height: 1.15;
  }
  .lang a {
    margin: 0;
    min-width: 1.6em;
    text-align: center;
  }
}