:root {
  --ink: #18211c;
  --muted: #5d665f;
  --line: #d8ddd5;
  --paper: #f6f5ef;
  --white: #ffffff;
  --copper: #ad5f2c;
  --green: #285c4b;
  --steel: #64747a;
  --charcoal: #101713;
  --shadow: 0 18px 50px rgba(16, 23, 19, 0.15);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Microsoft YaHei", "PingFang SC", "Segoe UI", Arial, sans-serif;
  line-height: 1.6;
}

img {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
  text-decoration: none;
}

.site-header {
  position: fixed;
  z-index: 20;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 18px clamp(20px, 5vw, 64px);
  color: var(--white);
  transition: background 180ms ease, color 180ms ease, box-shadow 180ms ease;
}

.site-header.is-scrolled,
.site-header.is-open {
  color: var(--ink);
  background: rgba(246, 245, 239, 0.96);
  box-shadow: 0 10px 35px rgba(16, 23, 19, 0.08);
  backdrop-filter: blur(18px);
}

.brand {
  display: flex;
  align-items: center;
  min-width: min(360px, 46vw);
  max-width: 430px;
}

.brand-logo {
  width: 100%;
  height: 52px;
  object-fit: contain;
  object-position: left center;
  padding: 7px 10px;
  background: rgba(255, 255, 255, 0.94);
  box-shadow: 0 8px 24px rgba(16, 23, 19, 0.12);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: clamp(16px, 2.4vw, 30px);
  font-size: 14px;
}

.site-nav a {
  opacity: 0.9;
}

.site-nav a:hover {
  opacity: 1;
}

.language-switcher {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  padding: 3px;
  border: 1px solid rgba(255, 255, 255, 0.55);
  background: rgba(255, 255, 255, 0.1);
}

.site-header.is-scrolled .language-switcher,
.site-header.is-open .language-switcher {
  border-color: var(--line);
  background: var(--white);
}

.language-switcher button {
  min-width: 38px;
  height: 30px;
  border: 0;
  color: inherit;
  background: transparent;
  font: inherit;
  font-size: 12px;
  font-weight: 800;
  cursor: pointer;
}

.language-switcher button[aria-pressed="true"] {
  color: var(--white);
  background: var(--green);
}

.menu-button {
  display: none;
  width: 42px;
  height: 42px;
  padding: 10px;
  border: 1px solid currentColor;
  background: transparent;
  color: inherit;
}

.menu-button span {
  display: block;
  height: 2px;
  margin: 5px 0;
  background: currentColor;
}

.hero {
  position: relative;
  min-height: 92vh;
  display: grid;
  align-items: center;
  overflow: hidden;
  color: var(--white);
}

.hero-image,
.hero-shade {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.hero-image {
  object-fit: cover;
}

.hero-shade {
  background:
    linear-gradient(90deg, rgba(16, 23, 19, 0.8) 0%, rgba(16, 23, 19, 0.52) 36%, rgba(16, 23, 19, 0.08) 72%),
    linear-gradient(0deg, rgba(16, 23, 19, 0.55) 0%, rgba(16, 23, 19, 0) 42%);
}

.hero-content {
  position: relative;
  z-index: 2;
  width: min(760px, calc(100% - 40px));
  margin-left: clamp(20px, 7vw, 92px);
  padding-top: 72px;
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--copper);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.hero .eyebrow {
  color: #f5c084;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 700px;
  margin-bottom: 22px;
  font-size: clamp(42px, 6vw, 78px);
  line-height: 1.05;
  letter-spacing: 0;
}

.hero-copy {
  max-width: 640px;
  margin-bottom: 34px;
  color: rgba(255, 255, 255, 0.88);
  font-size: clamp(17px, 2vw, 21px);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 11px 20px;
  border: 1px solid transparent;
  font-weight: 700;
  white-space: nowrap;
}

.button.primary {
  color: var(--white);
  background: var(--green);
}

.button.secondary {
  color: var(--white);
  border-color: rgba(255, 255, 255, 0.7);
}

.button:hover {
  transform: translateY(-1px);
}

.hero-panel {
  position: absolute;
  z-index: 3;
  right: clamp(20px, 5vw, 64px);
  bottom: 54px;
  width: min(360px, calc(100% - 40px));
  padding: 24px;
  background: rgba(246, 245, 239, 0.92);
  color: var(--ink);
  box-shadow: var(--shadow);
  backdrop-filter: blur(18px);
}

.hero-panel span,
.fact-list span {
  display: block;
  color: var(--muted);
  font-size: 12px;
}

.hero-panel strong {
  display: block;
  margin: 2px 0 16px;
  font-size: 20px;
}

.hero-panel strong:last-child {
  margin-bottom: 0;
}

.intro-band {
  background: var(--charcoal);
  color: var(--white);
}

.intro-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
}

.intro-grid > div {
  min-height: 150px;
  padding: 34px clamp(20px, 4vw, 42px);
  border-left: 1px solid rgba(255, 255, 255, 0.16);
}

.intro-grid > div:last-child {
  border-right: 1px solid rgba(255, 255, 255, 0.16);
}

.metric {
  color: #e09a5e;
  font-size: 13px;
  font-weight: 800;
}

.intro-grid p {
  margin: 12px 0 0;
  font-size: 18px;
  font-weight: 700;
}

.section {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
  padding: clamp(72px, 9vw, 116px) 0;
}

.section-heading {
  max-width: 720px;
  margin-bottom: 36px;
}

h2 {
  margin-bottom: 0;
  font-size: clamp(30px, 4vw, 48px);
  line-height: 1.15;
}

h3 {
  margin-bottom: 12px;
  font-size: 22px;
  line-height: 1.25;
}

.two-column {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(320px, 0.85fr);
  gap: clamp(36px, 6vw, 78px);
  align-items: start;
}

.lead-block {
  color: #394139;
  font-size: 19px;
}

.fact-list {
  border-top: 1px solid var(--line);
}

.fact-list div {
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}

.fact-list strong {
  display: block;
  margin-top: 4px;
  font-size: 18px;
}

.project-section {
  width: 100%;
  max-width: none;
  padding-left: max(20px, calc((100% - 1180px) / 2));
  padding-right: max(20px, calc((100% - 1180px) / 2));
  background: #e7e5db;
}

.project-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(300px, 430px);
  gap: clamp(28px, 5vw, 56px);
}

.project-feature {
  min-height: 440px;
  padding: clamp(28px, 5vw, 54px);
  color: var(--white);
  background:
    linear-gradient(130deg, rgba(24, 33, 28, 0.92), rgba(40, 92, 75, 0.72)),
    url("assets/hero-mining.png") center / cover;
}

.tag {
  display: inline-flex;
  margin-bottom: 24px;
  padding: 7px 10px;
  color: #f5c084;
  border: 1px solid rgba(245, 192, 132, 0.55);
  font-size: 12px;
  font-weight: 800;
  text-transform: uppercase;
}

.project-feature h3 {
  max-width: 620px;
  font-size: clamp(30px, 4vw, 48px);
}

.project-feature p {
  max-width: 760px;
  color: rgba(255, 255, 255, 0.86);
  font-size: 18px;
}

dl {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin: 34px 0 0;
}

dt {
  color: rgba(255, 255, 255, 0.62);
  font-size: 12px;
}

dd {
  margin: 4px 0 0;
  font-weight: 700;
}

.timeline {
  display: grid;
  gap: 14px;
}

.timeline div,
.capability-grid article,
.responsibility-grid div {
  padding: 24px;
  background: var(--white);
  box-shadow: 0 1px 0 rgba(16, 23, 19, 0.06);
}

.timeline span {
  display: inline-grid;
  width: 42px;
  height: 42px;
  place-items: center;
  margin-bottom: 14px;
  color: var(--white);
  background: var(--green);
  font-weight: 800;
}

.timeline p,
.capability-grid p,
.responsibility-grid p {
  margin-bottom: 0;
  color: var(--muted);
}

.copper-section {
  width: 100%;
  max-width: none;
  padding-left: max(20px, calc((100% - 1180px) / 2));
  padding-right: max(20px, calc((100% - 1180px) / 2));
  background: var(--paper);
}

.copper-layout {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 16px;
  align-items: stretch;
}

.copper-card,
.copper-pillars > div {
  background: var(--white);
  box-shadow: 0 1px 0 rgba(16, 23, 19, 0.06);
}

.copper-symbol {
  min-height: 310px;
  display: grid;
  align-content: center;
  padding: 28px;
  color: var(--white);
  background:
    linear-gradient(135deg, rgba(173, 95, 44, 0.94), rgba(40, 92, 75, 0.92)),
    url("assets/hero-mining.png") center / cover;
}

.copper-symbol span {
  font-size: 32px;
  font-weight: 800;
}

.copper-symbol strong {
  margin: 6px 0 16px;
  font-size: 76px;
  line-height: 0.95;
}

.copper-symbol p {
  margin-bottom: 0;
  color: rgba(255, 255, 255, 0.86);
}

.copper-approach {
  padding: clamp(28px, 5vw, 48px);
}

.copper-approach p {
  max-width: 820px;
  margin-bottom: 0;
  color: var(--muted);
  font-size: 18px;
}

.copper-pillars {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.copper-pillars > div {
  min-height: 210px;
  padding: 24px;
  border-top: 4px solid var(--copper);
}

.copper-pillars span {
  color: var(--copper);
  font-size: 12px;
  font-weight: 800;
}

.copper-pillars p {
  margin-bottom: 0;
  color: var(--muted);
}

.capability-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.capability-grid article {
  min-height: 250px;
  border-top: 4px solid var(--copper);
}

.responsibility {
  border-top: 1px solid var(--line);
}

.responsibility-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.contact-section {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(320px, 0.62fr);
  gap: clamp(34px, 6vw, 76px);
  align-items: start;
  padding: clamp(64px, 8vw, 96px) max(20px, calc((100% - 1180px) / 2));
  color: var(--white);
  background: var(--charcoal);
}

.contact-section p {
  max-width: 680px;
  color: rgba(255, 255, 255, 0.76);
  font-size: 18px;
}

.contact-form {
  display: grid;
  gap: 16px;
  padding: 26px;
  color: var(--ink);
  background: var(--paper);
}

label {
  display: grid;
  gap: 7px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

input,
select,
textarea {
  width: 100%;
  min-height: 44px;
  border: 1px solid var(--line);
  padding: 10px 12px;
  color: var(--ink);
  background: var(--white);
  font: inherit;
}

textarea {
  resize: vertical;
}

input:focus,
select:focus,
textarea:focus {
  outline: 2px solid rgba(40, 92, 75, 0.28);
  border-color: var(--green);
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 28px;
  padding: 28px max(20px, calc((100% - 1180px) / 2));
  color: rgba(255, 255, 255, 0.68);
  background: #0b100d;
  font-size: 13px;
}

.site-footer strong,
.site-footer span {
  display: block;
}

.site-footer strong {
  color: var(--white);
  font-size: 15px;
}

.site-footer p {
  max-width: 640px;
  margin: 0;
}

@media (max-width: 980px) {
  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    padding: 16px 20px 24px;
    background: rgba(246, 245, 239, 0.98);
    color: var(--ink);
    box-shadow: 0 20px 35px rgba(16, 23, 19, 0.1);
  }

  .language-switcher {
    margin-left: auto;
  }

  .site-header.is-open .site-nav {
    display: grid;
  }

  .menu-button {
    display: block;
  }

  .hero {
    min-height: 880px;
    align-items: start;
  }

  .hero-content {
    width: calc(100% - 40px);
    margin: 0 auto;
    padding-top: 132px;
  }

  .hero-panel {
    left: 20px;
    right: 20px;
  }

  .intro-grid,
  .two-column,
  .project-layout,
  .copper-layout,
  .contact-section {
    grid-template-columns: 1fr;
  }

  .capability-grid,
  .responsibility-grid,
  .copper-pillars {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 680px) {
  .site-header {
    padding: 14px 16px;
  }

  .brand {
    min-width: 0;
    width: min(230px, calc(100vw - 154px));
  }

  .brand-logo {
    height: 42px;
    padding: 6px 8px;
  }

  .hero {
    min-height: 820px;
  }

  h1 {
    font-size: 39px;
  }

  .hero-copy {
    font-size: 16px;
  }

  .button {
    width: 100%;
  }

  .intro-grid,
  .capability-grid,
  .responsibility-grid,
  .copper-pillars,
  dl {
    grid-template-columns: 1fr;
  }

  .intro-grid > div,
  .intro-grid > div:last-child {
    min-height: auto;
    border-right: 0;
    border-left: 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.16);
  }

  .project-feature {
    min-height: auto;
  }

  .site-footer {
    display: grid;
  }
}