:root {
  --ink: #18212f;
  --muted: #647084;
  --line: #e5e8ee;
  --paper: #fbfaf7;
  --panel: #ffffff;
  --accent: #0f8f7b;
  --accent-dark: #0b5f55;
  --warm: #d99145;
  --shadow: 0 18px 50px rgba(24, 33, 47, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

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

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 18px clamp(20px, 5vw, 72px);
  background: rgba(251, 250, 247, 0.9);
  border-bottom: 1px solid rgba(229, 232, 238, 0.8);
  backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 800;
  white-space: nowrap;
}

.brand-mark {
  display: grid;
  width: 36px;
  height: 36px;
  place-items: center;
  color: #fff;
  background: var(--accent);
  border-radius: 8px;
}

.nav {
  display: flex;
  align-items: center;
  gap: clamp(14px, 3vw, 34px);
  color: var(--muted);
  font-size: 15px;
}

.nav a:hover {
  color: var(--accent-dark);
}

.hero {
  min-height: 76vh;
  display: grid;
  align-items: center;
  padding: 80px clamp(20px, 5vw, 72px);
  color: #fff;
  background:
    linear-gradient(90deg, rgba(14, 29, 43, 0.88), rgba(14, 29, 43, 0.46)),
    url("https://images.unsplash.com/photo-1600585154340-be6161a56a0c?auto=format&fit=crop&w=1800&q=80")
      center / cover;
}

.hero-content {
  max-width: 780px;
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--warm);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.hero h1,
.section h2,
.contact-section h2 {
  margin: 0;
  line-height: 1.12;
}

.hero h1 {
  font-size: clamp(48px, 8vw, 92px);
  font-weight: 900;
}

.hero-copy {
  max-width: 650px;
  margin: 24px 0 0;
  color: rgba(255, 255, 255, 0.9);
  font-size: clamp(18px, 2vw, 23px);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 34px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 22px;
  border: 1px solid transparent;
  border-radius: 8px;
  font-weight: 800;
}

.button.primary {
  color: #fff;
  background: var(--accent);
}

.button.primary:hover {
  background: var(--accent-dark);
}

.button.secondary {
  color: #fff;
  border-color: rgba(255, 255, 255, 0.55);
}

.button.secondary:hover {
  background: rgba(255, 255, 255, 0.12);
}

.section {
  padding: 84px clamp(20px, 5vw, 72px);
}

.section-heading {
  max-width: 780px;
  margin-bottom: 34px;
}

.section h2,
.contact-section h2 {
  font-size: clamp(32px, 5vw, 52px);
}

.service-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 22px;
}

.service-card {
  min-height: 286px;
  padding: 28px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.service-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  margin-bottom: 32px;
  color: #fff;
  background: var(--accent-dark);
  border-radius: 8px;
  font-weight: 900;
}

.service-card:nth-child(2) .service-icon {
  background: var(--warm);
}

.service-card:nth-child(3) .service-icon {
  background: #2d5b8f;
}

.service-card:nth-child(4) .service-icon {
  background: #7b4b94;
}

.service-card-featured {
  scroll-margin-top: 96px;
}

.service-card h3 {
  margin: 0 0 12px;
  font-size: 24px;
}

.service-card p,
.feature-list p,
.contact-section p {
  margin: 0;
  color: var(--muted);
}

.text-link {
  display: inline-flex;
  margin-top: 20px;
  color: var(--accent-dark);
  font-weight: 800;
}

.text-link:hover {
  color: var(--accent);
}

.split-section {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  gap: clamp(28px, 6vw, 80px);
  background: #ffffff;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.feature-list {
  display: grid;
  gap: 18px;
  font-size: 18px;
}

.feature-list p {
  padding-left: 18px;
  border-left: 4px solid var(--accent);
}

.contact-section {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  margin: 72px clamp(20px, 5vw, 72px);
  padding: 42px;
  color: #fff;
  background: var(--ink);
  border-radius: 8px;
}

.contact-section p {
  max-width: 680px;
  margin-top: 14px;
  color: rgba(255, 255, 255, 0.78);
}

.site-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 26px clamp(20px, 5vw, 72px);
  color: var(--muted);
  border-top: 1px solid var(--line);
}

@media (max-width: 820px) {
  .site-header,
  .site-footer,
  .contact-section {
    align-items: flex-start;
    flex-direction: column;
  }

  .hero {
    min-height: 70vh;
    padding-top: 68px;
    padding-bottom: 68px;
  }

  .service-grid,
  .split-section {
    grid-template-columns: 1fr;
  }

  .service-card {
    min-height: auto;
  }

  .contact-section {
    margin-top: 52px;
    margin-bottom: 52px;
    padding: 30px;
  }
}

@media (min-width: 821px) and (max-width: 1120px) {
  .service-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 520px) {
  .nav {
    width: 100%;
    justify-content: space-between;
  }

  .hero h1 {
    font-size: 46px;
  }

  .button {
    width: 100%;
  }
}