:root {
  --bg: #F8FAFC;
  --surface: #F1F5F9;
  --surface-alt: #E2E8F0;
  --text: #1E293B;
  --muted: #64748B;
  --primary: #0F766E;
  --accent: #0D9488;
  --card: #FFFFFF;
  --border: #CBD5E1;
}

* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: "Inter", "Roboto", -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  margin: 0;
}

a {
  color: var(--text);
  text-decoration: none;
}

.container {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 20px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: linear-gradient(180deg, rgba(240,242,245,0.9), rgba(240,242,245,0.5) 60%, rgba(240,242,245,0));
  border-bottom: 1px solid rgba(52,152,219,0.15); /* 使用科技蓝作为边框的淡化色 */
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  font-weight: 700;
  letter-spacing: 0.6px;
  color: var(--accent);
  font-size: 18px;
}

.logo-mark {
  width: 40px;
  height: 40px;
  border-radius: 16px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 8px 20px rgba(15, 118, 110, 0.25);
  margin-right: 12px;
  position: relative;
  overflow: hidden;
}

.logo-mark::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: linear-gradient(45deg, transparent 30%, rgba(255,255,255,0.1) 50%, transparent 70%);
  animation: shimmer 3s infinite;
}

@keyframes shimmer {
  0% { transform: translateX(-100%) rotate(45deg); }
  100% { transform: translateX(100%) rotate(45deg); }
}

.logo-initial {
  font-size: 20px;
  color: var(--card);
  font-weight: 700;
  letter-spacing: 1px;
}

.logo-text {
  font-size: 16px;
  color: var(--primary);
}

.menu a {
  margin-left: 18px;
  padding: 8px 10px;
  border-radius: 8px;
  transition: 0.2s ease;
  color: var(--muted);
  position: relative;
}

.menu a.active {
  color: var(--text);
  background: rgba(15, 118, 110, 0.1);
}

.menu a:hover {
  color: var(--text);
  background: rgba(15, 118, 110, 0.08);
}

.hero {
  background:
    radial-gradient(1000px 380px at 10% 10%, rgba(15, 118, 110, 0.08), transparent 60%),
    radial-gradient(900px 320px at 80% 0%, rgba(13, 148, 136, 0.1), transparent 60%),
    linear-gradient(180deg, var(--surface), var(--bg) 50%, var(--bg));
  padding: 96px 0 72px;
}

.hero-inner {
  text-align: center;
}

.hero h1 {
  margin: 0 0 16px;
  font-size: 36px;
  line-height: 1.2;
}

.hero-sub {
  padding: 80px 0 56px;
  background:
    radial-gradient(800px 260px at 10% 0%, rgba(52,152,219,0.15), transparent 60%), /* 使用科技蓝 */
    linear-gradient(180deg, var(--surface), var(--bg) 60%);
}

.hero-sub-inner {
  max-width: 720px;
}

.subtitle {
  margin: 0 auto 28px;
  max-width: 720px;
  color: var(--muted);
  font-size: 16px;
}

.cta {
  display: inline-block;
  padding: 12px 18px;
  border-radius: 10px;
  background: linear-gradient(45deg, var(--primary), var(--accent));
  color: var(--text); /* 确保在亮色背景下有良好对比度 */
  font-weight: 600;
  transition: transform 0.15s ease;
}

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

.section {
  padding: 72px 0;
}

.section-alt {
  background: var(--surface);
}

h2 {
  margin: 0 0 18px;
  font-size: 24px;
}

p {
  color: var(--muted);
  line-height: 1.8;
  font-size: 15px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px;
  box-shadow: 0 6px 18px rgba(0,0,0,0.1);
}

.card h3 {
  margin: 0 0 8px;
  font-size: 18px;
}

.card-icon {
  width: 32px;
  height: 32px;
  border-radius: 999px;
  background: rgba(52,152,219,0.1); /* 使用科技蓝淡化背景 */
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 10px;
}

.card-icon svg {
  width: 18px;
  height: 18px;
  fill: var(--accent); /* 图标填充色 */
}

.case {
  background:
    linear-gradient(180deg, rgba(15, 118, 110, 0.06), rgba(0,0,0,0) 40%),
    var(--card);
}

.metrics {
  display: flex;
  justify-content: center;
  gap: 32px;
  flex-wrap: wrap;
  margin-top: 32px;
}

.metric {
  min-width: 120px;
  text-align: left;
}

.metric-value {
  font-size: 28px;
  font-weight: 700;
  color: var(--primary);
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.metric-label {
  margin-top: 4px;
  font-size: 14px;
  color: var(--muted);
}

.contact {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}

.label {
  color: var(--muted);
  font-size: 13px;
}

.value {
  margin-top: 6px;
  font-weight: 600;
}

.site-footer {
  border-top: 1px solid var(--border);
  background: var(--surface-alt);
  color: var(--muted);
}

.footer-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
  }
  
  .steps {
    display: flex;
    flex-direction: column;
    gap: 32px;
    margin-top: 32px;
    position: relative;
    padding-left: 20px;
  }
  
  .steps::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border);
  }
  
  .step {
    position: relative;
  }
  
  .step-index {
    position: absolute;
    left: -20px;
    top: 0;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--primary);
    color: var(--card);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 18px;
    border: 2px solid var(--accent);
    box-shadow: 0 0 0 4px var(--bg);
  }
  
  .step-body {
    margin-left: 30px;
  }
  
  .step-title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 8px;
  }
  
  .step-text {
    color: var(--muted);
    font-size: 15px;
    line-height: 1.6;
  }
  
  @media (max-width: 960px) {
    .grid {
      grid-template-columns: 1fr 1fr;
    }
    .contact {
      grid-template-columns: 1fr;
    }
  }
  
  @media (max-width: 600px) {
    .menu {
      display: none;
    }
    .hero h1 {
      font-size: 28px;
    }
    .subtitle {
      font-size: 14px;
    }
    .grid {
      grid-template-columns: 1fr;
    }
    .steps {
      padding-left: 0;
    }
    .steps::before {
      left: 18px;
    }
    .step-index {
      left: 0;
    }
    .step-body {
      margin-left: 50px;
    }
  }
  
  html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  animation: fadeIn 0.5s ease-in;
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}