:root {
  --ink: #17202a;
  --muted: #5c6672;
  --line: #d9dee5;
  --paper: #f7f8fa;
  --white: #ffffff;
  --steel: #60707e;
  --blue: #1262a3;
  --green: #1e7d5b;
  --amber: #c07a26;
  --shadow: 0 18px 48px rgba(19, 32, 45, 0.16);
}

* {
  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;
}

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

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

.site-header {
  position: fixed;
  z-index: 20;
  top: 0;
  left: 0;
  right: 0;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 28px;
  min-height: 72px;
  padding: 14px clamp(18px, 4vw, 54px);
  color: var(--white);
  background: rgba(18, 26, 35, 0.78);
  border-bottom: 1px solid rgba(255, 255, 255, 0.16);
  backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  color: var(--white);
  font-weight: 800;
  background: linear-gradient(135deg, var(--blue), var(--green));
  border: 1px solid rgba(255, 255, 255, 0.32);
}

.brand strong,
.brand small {
  display: block;
  white-space: nowrap;
}

.brand small {
  color: rgba(255, 255, 255, 0.7);
  font-size: 12px;
}

.nav {
  display: flex;
  justify-content: center;
  gap: clamp(16px, 3vw, 34px);
  color: rgba(255, 255, 255, 0.82);
  font-size: 14px;
}

.nav a:hover,
.nav a:focus-visible {
  color: var(--white);
}

.header-action,
.primary-button,
.secondary-button,
.quote-form button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border: 1px solid transparent;
  font-weight: 700;
  cursor: pointer;
}

.header-action,
.primary-button,
.quote-form button {
  color: var(--white);
  background: var(--blue);
}

.secondary-button {
  color: var(--white);
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.4);
}

.menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 10px;
  color: var(--white);
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.28);
}

.menu-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  margin: 5px 0;
  background: currentColor;
}

.hero {
  position: relative;
  min-height: 92vh;
  display: grid;
  align-items: end;
  overflow: hidden;
  padding: 132px clamp(20px, 5vw, 72px) 54px;
  color: var(--white);
}

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

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

.hero-overlay {
  background:
    linear-gradient(90deg, rgba(9, 15, 22, 0.92), rgba(9, 15, 22, 0.58) 52%, rgba(9, 15, 22, 0.24)),
    linear-gradient(0deg, rgba(9, 15, 22, 0.74), transparent 42%);
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 780px;
  padding-bottom: 96px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--green);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.hero .eyebrow {
  color: #9ee2c3;
}

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

h1 {
  margin-bottom: 18px;
  max-width: 880px;
  font-size: clamp(40px, 7vw, 82px);
  line-height: 1.04;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 14px;
  font-size: clamp(28px, 4vw, 46px);
  line-height: 1.16;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 10px;
  font-size: 21px;
  line-height: 1.25;
}

.hero-copy {
  max-width: 680px;
  color: rgba(255, 255, 255, 0.82);
  font-size: clamp(17px, 2vw, 20px);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.hero-panel {
  position: absolute;
  z-index: 2;
  right: clamp(20px, 5vw, 72px);
  bottom: 36px;
  display: grid;
  grid-template-columns: repeat(2, minmax(180px, 250px));
  gap: 12px;
}

.hero-panel div {
  padding: 18px;
  background: rgba(14, 24, 35, 0.74);
  border: 1px solid rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(12px);
}

.hero-panel span {
  color: #9ee2c3;
  font-weight: 800;
}

.hero-panel strong {
  display: block;
  margin: 6px 0;
}

.hero-panel p {
  margin-bottom: 0;
  color: rgba(255, 255, 255, 0.72);
  font-size: 14px;
}

section {
  padding: clamp(68px, 8vw, 112px) clamp(20px, 5vw, 72px);
}

.section-band {
  background: var(--white);
}

.intro {
  display: grid;
  grid-template-columns: minmax(240px, 0.78fr) minmax(280px, 1fr);
  gap: clamp(28px, 5vw, 74px);
  align-items: start;
}

.intro > p,
.quality-copy p,
.timeline p,
.capability-grid p,
.contact-card p {
  color: var(--muted);
}

.section-heading {
  max-width: 760px;
}

.capability-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin-top: 34px;
}

.capability-grid article {
  min-width: 0;
  background: var(--white);
  border: 1px solid var(--line);
  box-shadow: 0 10px 28px rgba(24, 36, 48, 0.08);
}

.capability-grid img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.capability-grid article div {
  padding: 24px;
}

.quality-layout {
  display: grid;
  grid-template-columns: minmax(280px, 1fr) minmax(300px, 0.86fr);
  gap: clamp(28px, 6vw, 86px);
  align-items: center;
  margin-top: 22px;
}

.check-list {
  display: grid;
  gap: 12px;
  padding: 0;
  margin: 26px 0 0;
  list-style: none;
}

.check-list li {
  position: relative;
  padding-left: 28px;
}

.check-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.6em;
  width: 12px;
  height: 12px;
  background: var(--green);
}

.metric-board {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.metric-board div {
  min-height: 136px;
  padding: 22px;
  color: var(--white);
  background: var(--ink);
  border-left: 4px solid var(--green);
  box-shadow: var(--shadow);
}

.metric-board span {
  display: block;
  margin-bottom: 18px;
  color: rgba(255, 255, 255, 0.58);
}

.metric-board strong {
  font-size: 24px;
}

.timeline {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
  margin-top: 34px;
}

.timeline article {
  min-height: 250px;
  padding: 24px;
  background: var(--white);
  border-top: 5px solid var(--amber);
  box-shadow: 0 8px 24px rgba(24, 36, 48, 0.08);
}

.timeline span {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  margin-bottom: 32px;
  color: var(--white);
  font-weight: 800;
  background: var(--steel);
}

.contact-layout {
  display: grid;
  grid-template-columns: minmax(280px, 0.92fr) minmax(280px, 1fr);
  gap: clamp(24px, 5vw, 70px);
  align-items: start;
  margin-top: 24px;
}

.quote-form {
  display: grid;
  gap: 16px;
  padding: 26px;
  background: var(--paper);
  border: 1px solid var(--line);
}

.quote-form label {
  display: grid;
  gap: 7px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 700;
}

.quote-form input,
.quote-form textarea {
  width: 100%;
  padding: 13px 14px;
  color: var(--ink);
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 0;
  font: inherit;
}

.quote-form input:focus,
.quote-form textarea:focus {
  outline: 2px solid rgba(18, 98, 163, 0.24);
  border-color: var(--blue);
}

.quote-form textarea {
  resize: vertical;
}

.form-note {
  margin: 0;
  color: var(--muted);
  font-size: 13px;
}

.contact-card {
  padding: 34px;
  color: var(--white);
  background:
    linear-gradient(rgba(23, 32, 42, 0.86), rgba(23, 32, 42, 0.86)),
    url("assets/surface-finish.png") center / cover;
  box-shadow: var(--shadow);
}

.contact-card p {
  color: rgba(255, 255, 255, 0.72);
}

.contact-card a {
  display: inline-flex;
  margin-top: 16px;
  color: #9ee2c3;
  font-weight: 800;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 28px clamp(20px, 5vw, 72px);
  color: rgba(255, 255, 255, 0.72);
  background: #101820;
}

.site-footer p {
  margin: 0;
}

@media (max-width: 980px) {
  .site-header {
    grid-template-columns: 1fr auto;
  }

  .nav,
  .header-action {
    display: none;
  }

  .menu-toggle {
    display: block;
  }

  .site-header.is-open .nav {
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    display: grid;
    justify-content: stretch;
    gap: 0;
    padding: 8px 20px 18px;
    background: rgba(18, 26, 35, 0.96);
  }

  .site-header.is-open .nav a {
    padding: 14px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  }

  .hero {
    min-height: 880px;
  }

  .hero-content {
    padding-bottom: 220px;
  }

  .hero-panel,
  .intro,
  .quality-layout,
  .contact-layout {
    grid-template-columns: 1fr;
  }

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

  .capability-grid,
  .timeline {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 640px) {
  .site-header {
    min-height: 66px;
    padding: 12px 16px;
  }

  .brand small {
    display: none;
  }

  .hero {
    min-height: 820px;
    padding: 108px 18px 28px;
  }

  .hero-content {
    padding-bottom: 260px;
  }

  .hero-panel,
  .capability-grid,
  .timeline,
  .metric-board {
    grid-template-columns: 1fr;
  }

  .hero-panel {
    bottom: 22px;
  }

  .hero-actions a,
  .quote-form button {
    width: 100%;
  }

  section {
    padding: 58px 18px;
  }

  .site-footer {
    display: grid;
  }
}