:root {
  --ink: #111827;
  --muted: #5b6675;
  --line: #dde4ec;
  --paper: #f4f7fa;
  --white: #ffffff;
  --navy: #0d2338;
  --teal: #058f95;
  --red: #d40000;
  --gold: #c89b3c;
  --steel: #e9eef4;
  --shadow: 0 22px 60px rgba(12, 28, 46, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    linear-gradient(180deg, #ffffff 0, var(--paper) 520px),
    var(--paper);
  font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  line-height: 1.6;
}

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

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 82px;
  padding: 0 7vw;
  background: rgba(255, 255, 255, 0.88);
  border-bottom: 1px solid rgba(221, 228, 236, 0.76);
  box-shadow: 0 10px 32px rgba(13, 35, 56, 0.06);
  backdrop-filter: blur(18px);
}

.brand,
.main-nav,
.hero-actions,
.site-footer {
  display: flex;
  align-items: center;
}

.brand {
  gap: 0;
  font-weight: 700;
  color: var(--navy);
}

.brand-logo {
  width: min(58vw, 640px);
  height: 76px;
  object-fit: contain;
  object-position: left center;
  flex: 0 0 auto;
}

.main-nav {
  gap: 8px;
  color: var(--muted);
  font-size: 15px;
  font-weight: 700;
}

.main-nav a {
  padding: 10px 14px;
  border-radius: 8px;
  transition: color 0.2s ease, background 0.2s ease;
}

.main-nav a:hover {
  color: var(--red);
  background: rgba(212, 0, 0, 0.06);
}

.menu-button {
  display: none;
  width: 42px;
  height: 42px;
  padding: 10px;
  background: rgba(255, 255, 255, 0.78);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.menu-button span {
  display: block;
  height: 2px;
  margin: 5px 0;
  background: var(--ink);
}

.hero {
  position: relative;
  min-height: 92vh;
  display: flex;
  align-items: center;
  padding: 120px 7vw 70px;
  overflow: hidden;
  isolation: isolate;
}

.hero img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 64% 28%, rgba(5, 143, 149, 0.18), transparent 28%),
    linear-gradient(90deg, rgba(7, 18, 31, 0.92), rgba(9, 25, 42, 0.62), rgba(9, 25, 42, 0.1)),
    linear-gradient(0deg, rgba(13, 35, 56, 0.28), rgba(13, 35, 56, 0));
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 760px;
  color: var(--white);
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--gold);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  overflow-wrap: anywhere;
}

h1 {
  margin: 0;
  max-width: 720px;
  font-size: clamp(44px, 6.8vw, 78px);
  line-height: 1.02;
  letter-spacing: 0;
  text-wrap: balance;
}

h2 {
  margin: 0;
  max-width: 780px;
  font-size: clamp(29px, 4vw, 48px);
  line-height: 1.12;
  letter-spacing: 0;
  text-wrap: balance;
}

h3 {
  margin: 0 0 12px;
  font-size: 22px;
  line-height: 1.3;
}

.hero-copy {
  max-width: 620px;
  margin: 28px 0 34px;
  color: rgba(255, 255, 255, 0.9);
  font-size: 19px;
}

.hero-actions {
  gap: 14px;
  flex-wrap: wrap;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 24px;
  border: 1px solid transparent;
  border-radius: 8px;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button.primary {
  color: var(--white);
  background: linear-gradient(135deg, var(--red), #b90000);
  box-shadow: 0 14px 28px rgba(212, 0, 0, 0.22);
}

.button.secondary {
  color: var(--white);
  border-color: rgba(255, 255, 255, 0.42);
  background: rgba(255, 255, 255, 0.1);
}

.hero-metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  max-width: 650px;
  margin-top: 42px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(10px);
}

.hero-metrics div {
  padding: 18px 20px;
  border-right: 1px solid rgba(255, 255, 255, 0.16);
}

.hero-metrics div:last-child {
  border-right: 0;
}

.hero-metrics strong {
  display: block;
  color: var(--white);
  font-size: 30px;
  line-height: 1;
}

.hero-metrics span {
  display: block;
  margin-top: 8px;
  color: rgba(255, 255, 255, 0.72);
  font-size: 13px;
}

.section {
  padding: 96px 7vw;
}

.intro {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(280px, 0.9fr);
  gap: 56px;
  align-items: end;
  background: var(--white);
  border-bottom: 1px solid var(--line);
}

.intro p:last-child {
  margin: 0;
  color: var(--muted);
  font-size: 18px;
}

.section-heading {
  margin-bottom: 38px;
}

.service-grid,
.case-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
}

.card,
.case-row article,
.contact-form {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.card {
  position: relative;
  min-height: 260px;
  padding: 32px;
  overflow: hidden;
  transition: transform 0.22s ease, border-color 0.22s ease, box-shadow 0.22s ease;
}

.card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto;
  height: 4px;
  background: linear-gradient(90deg, var(--red), var(--teal));
}

.card:hover {
  transform: translateY(-5px);
  border-color: rgba(212, 0, 0, 0.24);
  box-shadow: 0 28px 70px rgba(12, 28, 46, 0.16);
}

.card-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  margin-bottom: 28px;
  color: var(--red);
  background: rgba(212, 0, 0, 0.08);
  border: 1px solid rgba(212, 0, 0, 0.16);
  border-radius: 8px;
  font-size: 16px;
  font-weight: 900;
}

.card-index {
  position: absolute;
  top: 30px;
  right: 30px;
  display: block;
  color: rgba(13, 35, 56, 0.22);
  font-size: 14px;
  font-weight: 800;
}

.card p,
.case-row p,
.feature span,
.contact-band p,
.site-footer {
  color: var(--muted);
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(320px, 1.1fr);
  gap: 56px;
  background:
    linear-gradient(135deg, #eef3f7 0%, #ffffff 100%);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.feature-list {
  display: grid;
  gap: 16px;
}

.feature {
  display: grid;
  grid-template-columns: 120px minmax(0, 1fr);
  gap: 18px;
  padding: 22px 24px;
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid rgba(221, 228, 236, 0.92);
  border-radius: 8px;
}

.feature strong {
  color: var(--red);
}

.case-row article {
  position: relative;
  padding: 30px;
  box-shadow: none;
  background:
    linear-gradient(180deg, #ffffff, #f9fbfd);
}

.case-row article span {
  display: inline-block;
  margin-bottom: 18px;
  color: var(--teal);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.contact-band {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(320px, 520px);
  gap: 54px;
  align-items: start;
  padding: 96px 7vw;
  color: var(--white);
  background:
    radial-gradient(circle at 86% 20%, rgba(5, 143, 149, 0.34), transparent 28%),
    linear-gradient(135deg, #0a1726, var(--navy) 48%, #1d3d4a);
}

.contact-band p {
  max-width: 620px;
  color: rgba(255, 255, 255, 0.75);
}

.contact-form {
  display: grid;
  gap: 18px;
  padding: 30px;
  color: var(--ink);
  box-shadow: 0 28px 80px rgba(0, 0, 0, 0.18);
}

label {
  display: grid;
  gap: 8px;
  font-weight: 700;
}

input,
textarea {
  width: 100%;
  padding: 13px 14px;
  color: var(--ink);
  font: inherit;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfcfd;
  outline: none;
}

input:focus,
textarea:focus {
  border-color: var(--red);
  box-shadow: 0 0 0 4px rgba(212, 0, 0, 0.09);
}

.form-note {
  min-height: 24px;
  margin: 0;
  color: var(--red);
  font-weight: 700;
}

.site-footer {
  justify-content: space-between;
  gap: 20px;
  padding: 26px 7vw;
  background: #ffffff;
  border-top: 1px solid var(--line);
  font-size: 14px;
}

@media (max-width: 820px) {
  .site-header {
    height: 72px;
    padding: 0 22px;
  }

  .brand-logo {
    width: min(68vw, 350px);
    height: 58px;
  }

  .menu-button {
    display: block;
  }

  .main-nav {
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 10px 22px 22px;
    background: var(--white);
    border-bottom: 1px solid var(--line);
  }

  .main-nav.is-open {
    display: flex;
  }

  .main-nav a {
    padding: 14px 0;
    border-bottom: 1px solid var(--line);
  }

  .hero {
    min-height: 86vh;
    padding: 108px 22px 56px;
  }

  .hero-overlay {
    background: linear-gradient(90deg, rgba(10, 23, 38, 0.87), rgba(10, 23, 38, 0.6));
  }

  .hero-copy {
    font-size: 17px;
  }

  .section,
  .contact-band {
    padding: 64px 22px;
  }

  .intro,
  .split,
  .contact-band,
  .service-grid,
  .case-row {
    grid-template-columns: 1fr;
  }

  .feature {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .site-footer {
    flex-direction: column;
    align-items: flex-start;
    padding: 24px 22px;
  }
}

@media (max-width: 460px) {
  .brand-logo {
    width: min(70vw, 300px);
    height: 52px;
  }

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

  .contact-form {
    padding: 22px;
  }
}