:root {
  --color-bg: #ffffff;
  --color-bg-alt: #f7f8fa;
  --color-text: #1a1a1a;
  --color-muted: #6b7280;
  --color-border: #e5e7eb;
  --color-primary: #ff6a3d;
  --color-primary-dark: #e85528;
  --color-accent: #fff3ee;
  --radius: 12px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
  --maxw: 1120px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei",
    "Helvetica Neue", Helvetica, Arial, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }

.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--color-border);
}
.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 18px;
}
.logo-mark { font-size: 22px; }
.nav {
  display: flex;
  align-items: center;
  gap: 28px;
}
.nav a {
  font-size: 14px;
  color: var(--color-muted);
  transition: color 0.2s;
}
.nav a:hover { color: var(--color-text); }

.nav-toggle {
  display: none;
  width: 36px;
  height: 36px;
  background: none;
  border: 0;
  cursor: pointer;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  padding: 0;
}
.nav-toggle span {
  display: block;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 12px 22px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.2s;
}
.btn-sm { padding: 8px 16px; font-size: 14px; }
.btn-primary { background: var(--color-primary); color: #fff; }
.btn-primary:hover { background: var(--color-primary-dark); }
.btn-ghost {
  background: transparent;
  border-color: var(--color-border);
  color: var(--color-text);
}
.btn-ghost:hover { border-color: var(--color-text); }

/* Hero */
.hero {
  background:
    radial-gradient(1000px 400px at 80% -10%, var(--color-accent), transparent 60%),
    radial-gradient(800px 300px at 0% 10%, #fff8e6, transparent 60%);
  padding: 96px 0 80px;
}
.hero-inner { text-align: center; }
.hero h1 {
  font-size: clamp(32px, 5vw, 52px);
  line-height: 1.2;
  margin: 0 0 20px;
  letter-spacing: -0.02em;
}
.hero .lead {
  font-size: 18px;
  color: var(--color-muted);
  max-width: 640px;
  margin: 0 auto 32px;
}
.hero-cta {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 56px;
}
.hero-meta {
  display: flex;
  justify-content: center;
  gap: 56px;
  flex-wrap: wrap;
}
.hero-meta strong {
  display: block;
  font-size: 28px;
  color: var(--color-primary);
}
.hero-meta span { font-size: 14px; color: var(--color-muted); }

/* Sections */
.section { padding: 88px 0; }
.section-alt { background: var(--color-bg-alt); }
.section-head {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 56px;
}
.section-head h2 {
  font-size: clamp(26px, 3.4vw, 36px);
  margin: 0 0 12px;
  letter-spacing: -0.01em;
}
.section-head p { color: var(--color-muted); margin: 0; }

/* Grid */
.grid { display: grid; gap: 24px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* Cards */
.card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 32px 28px;
  transition: transform 0.25s, box-shadow 0.25s, border-color 0.25s;
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
  border-color: transparent;
}
.card-icon { font-size: 32px; margin-bottom: 16px; }
.card h3 { margin: 0 0 10px; font-size: 20px; }
.card p { color: var(--color-muted); margin: 0 0 16px; }
.card ul {
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 14px;
}
.card ul li {
  padding: 6px 0;
  border-top: 1px dashed var(--color-border);
}
.card ul li:first-child { border-top: 0; }

/* Feature */
.feature { padding: 8px; }
.feature h4 { margin: 0 0 8px; font-size: 17px; }
.feature p { margin: 0; color: var(--color-muted); font-size: 14px; }

/* Logos */
.logos {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 16px;
}
.logo-item {
  background: var(--color-bg-alt);
  border-radius: var(--radius);
  padding: 28px 12px;
  text-align: center;
  color: var(--color-muted);
  font-weight: 600;
  font-size: 15px;
}

/* CTA */
.section-cta {
  background: linear-gradient(135deg, #1a1a1a 0%, #2d1810 100%);
  color: #fff;
}
.section-cta h2 { color: #fff; margin: 0 0 12px; font-size: 32px; }
.section-cta p { color: rgba(255, 255, 255, 0.7); margin: 0 0 32px; }
.cta-inner { text-align: center; max-width: 640px; margin: 0 auto; }
.contact-form {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr auto;
  gap: 12px;
}
.contact-form input {
  padding: 14px 16px;
  border-radius: 10px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  background: rgba(255, 255, 255, 0.06);
  color: #fff;
  font-size: 15px;
  outline: none;
}
.contact-form input::placeholder { color: rgba(255, 255, 255, 0.5); }
.contact-form input:focus { border-color: var(--color-primary); }
.form-tip {
  margin: 16px 0 0;
  font-size: 14px;
  min-height: 20px;
  color: var(--color-primary);
}

/* Footer */
.site-footer {
  background: #0f0f10;
  color: #cfd1d6;
  padding: 56px 0 24px;
  font-size: 14px;
}
.footer-inner {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 32px;
  margin-bottom: 32px;
}
.site-footer h5 { color: #fff; margin: 0 0 12px; font-size: 14px; }
.site-footer a,
.site-footer p {
  display: block;
  color: #9aa0a6;
  margin: 6px 0;
}
.site-footer a:hover { color: #fff; }
.logo-footer { color: #fff; margin-bottom: 12px; }
.copyright {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 20px;
  color: #6b7280;
  font-size: 13px;
  text-align: center;
}

/* Responsive */
@media (max-width: 900px) {
  .grid-3 { grid-template-columns: 1fr 1fr; }
  .grid-4 { grid-template-columns: 1fr 1fr; }
  .logos { grid-template-columns: repeat(3, 1fr); }
  .footer-inner { grid-template-columns: 1fr 1fr; }
  .contact-form { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 640px) {
  .nav-toggle { display: flex; }
  .nav {
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    background: #fff;
    border-bottom: 1px solid var(--color-border);
    padding: 16px 24px;
    gap: 14px;
    display: none;
  }
  .nav.open { display: flex; }
  .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .logos { grid-template-columns: 1fr 1fr; }
  .footer-inner { grid-template-columns: 1fr; }
  .contact-form { grid-template-columns: 1fr; }
  .hero { padding: 64px 0 56px; }
  .section { padding: 64px 0; }
  .hero-meta { gap: 32px; }
}