:root {
  --brand: #1f6feb;
  --brand-2: #13c2c2;
  --ink: #0f172a;
  --muted: #5b6b82;
  --line: #e6eaf2;
  --bg: #ffffff;
  --bg-alt: #f5f8fc;
  --radius: 16px;
  --shadow: 0 10px 30px rgba(20, 50, 90, 0.08);
  --shadow-hover: 0 18px 48px rgba(20, 50, 90, 0.16);
  --maxw: 1140px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
a { color: inherit; text-decoration: none; }
h1, h2, h3 { line-height: 1.25; font-weight: 700; }

/* 按钮 */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 12px 26px; border-radius: 999px; font-weight: 600; font-size: 15px;
  cursor: pointer; border: 1px solid transparent; transition: all .25s ease;
}
.btn-primary { background: linear-gradient(135deg, var(--brand), var(--brand-2)); color: #fff; box-shadow: var(--shadow); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: var(--shadow-hover); }
.btn-ghost { background: rgba(255,255,255,.12); color: #fff; border-color: rgba(255,255,255,.5); }
.btn-ghost:hover { background: rgba(255,255,255,.22); }
.btn-block { width: 100%; }

/* 导航 */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 50;
  transition: all .3s ease; background: transparent;
}
.navbar.scrolled {
  background: rgba(255,255,255,.92); backdrop-filter: blur(10px);
  box-shadow: 0 2px 16px rgba(20,50,90,.08);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; color: var(--ink); }
.navbar:not(.scrolled) .brand { color: #fff; }
.brand-mark {
  width: 34px; height: 34px; border-radius: 9px; display: grid; place-items: center;
  background: linear-gradient(135deg, var(--brand), var(--brand-2)); color: #fff; font-weight: 800;
}
.brand-text em { font-style: normal; color: var(--brand); font-weight: 700; }
.navbar:not(.scrolled) .brand-text em { color: #bfe9ff; }
.nav-links { display: flex; align-items: center; gap: 28px; }
.nav-links a { font-size: 15px; font-weight: 500; color: var(--ink); opacity: .85; transition: opacity .2s; }
.nav-links a:hover, .nav-links a.active { opacity: 1; color: var(--brand); }
.navbar:not(.scrolled) .nav-links a { color: #eaf2ff; }
.navbar:not(.scrolled) .nav-links a.active { color: #fff; }
.nav-cta { color: #fff !important; opacity: 1 !important; }
.hamburger { display: none; flex-direction: column; gap: 5px; background: none; border: 0; cursor: pointer; padding: 6px; }
.hamburger span { width: 24px; height: 2px; background: var(--ink); transition: .3s; }
.navbar:not(.scrolled) .hamburger span { background: #fff; }

/* Hero */
.hero { position: relative; min-height: 100vh; display: flex; align-items: center; overflow: hidden; }
.hero-bg {
  position: absolute; inset: 0;
  background: radial-gradient(1200px 600px at 70% -10%, rgba(19,194,194,.35), transparent 60%),
              radial-gradient(900px 500px at 10% 20%, rgba(31,111,235,.45), transparent 55%),
              linear-gradient(135deg, #0b1f3a, #0e2b4d);
}
.hero-inner { position: relative; z-index: 1; color: #fff; padding-top: 80px; }
.hero-eyebrow { letter-spacing: 2px; font-size: 14px; color: #bfe9ff; margin-bottom: 18px; }
.hero-title { font-size: clamp(36px, 6vw, 64px); margin-bottom: 22px; }
.hero-sub { font-size: clamp(16px, 2vw, 20px); max-width: 620px; color: #dbe7f7; margin-bottom: 34px; }
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 56px; }
.hero-stats { display: flex; gap: 48px; flex-wrap: wrap; }
.stat { display: flex; flex-direction: column; }
.stat .num { font-size: 40px; font-weight: 800; background: linear-gradient(135deg,#fff,#bfe9ff); -webkit-background-clip: text; background-clip: text; color: transparent; }
.stat .label { font-size: 14px; color: #cdddf2; }

/* Section */
.section { padding: 96px 0; }
.section-alt { background: var(--bg-alt); }
.section-head { text-align: center; max-width: 720px; margin: 0 auto 56px; }
.kicker { display: inline-block; font-size: 13px; font-weight: 700; letter-spacing: 2px; color: var(--brand); margin-bottom: 12px; }
.section-head h2 { font-size: clamp(26px, 4vw, 38px); margin-bottom: 16px; }
.section-head p { color: var(--muted); font-size: 17px; }

/* About */
.about-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.about-card { background: var(--bg); border: 1px solid var(--line); border-radius: var(--radius); padding: 32px; box-shadow: var(--shadow); transition: transform .25s; }
.about-card:hover { transform: translateY(-4px); }
.about-card h3 { font-size: 20px; margin-bottom: 12px; color: var(--brand); }
.about-card p { color: var(--muted); }

/* Cards */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.card { background: var(--bg); border: 1px solid var(--line); border-radius: var(--radius); padding: 30px; box-shadow: var(--shadow); transition: transform .25s, box-shadow .25s; }
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow-hover); }
.card-icon { font-size: 34px; margin-bottom: 14px; }
.card h3 { font-size: 19px; margin-bottom: 10px; }
.card p { color: var(--muted); font-size: 15px; }

/* Contact */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: start; }
.contact-info h2 { font-size: clamp(26px, 4vw, 36px); margin: 12px 0 16px; }
.contact-info p { color: var(--muted); margin-bottom: 24px; }
.contact-list { list-style: none; display: flex; flex-direction: column; gap: 14px; }
.contact-list li { padding: 14px 18px; background: var(--bg-alt); border-radius: 12px; border: 1px solid var(--line); }
.contact-list strong { display: inline-block; width: 56px; color: var(--brand); }
.contact-form { background: var(--bg); border: 1px solid var(--line); border-radius: var(--radius); padding: 32px; box-shadow: var(--shadow); }
.field { margin-bottom: 18px; }
.field label { display: block; font-size: 14px; font-weight: 600; margin-bottom: 8px; }
.field input, .field textarea {
  width: 100%; padding: 12px 14px; border: 1px solid var(--line); border-radius: 10px;
  font-size: 15px; font-family: inherit; color: var(--ink); background: #fff; transition: border-color .2s, box-shadow .2s;
}
.field input:focus, .field textarea:focus { outline: none; border-color: var(--brand); box-shadow: 0 0 0 3px rgba(31,111,235,.12); }
.field textarea { resize: vertical; }
.form-tip { font-size: 13px; color: var(--muted); margin-top: 12px; text-align: center; }
.form-success { color: #0a8f4f; font-weight: 600; }
.form-error { color: #d23b3b; font-weight: 600; }

/* Footer */
.footer { background: #0b1f3a; color: #cdddf2; padding: 40px 0; }
.footer-inner { display: flex; flex-direction: column; gap: 12px; align-items: center; text-align: center; }
.footer-brand { display: flex; align-items: center; gap: 10px; font-weight: 700; color: #fff; }
.footer-copy { font-size: 13px; color: #8fa6c4; }
.footer-copy .beian-link { color: #8fa6c4; text-decoration: none; transition: color .2s; }
.footer-copy .beian-link:hover { color: #fff; text-decoration: underline; }

/* 响应式 */
@media (max-width: 860px) {
  .nav-links {
    position: fixed; top: 68px; right: 0; left: 0; flex-direction: column; gap: 0;
    background: #fff; padding: 12px 24px 20px; box-shadow: 0 12px 30px rgba(20,50,90,.12);
    transform: translateY(-130%); transition: transform .3s ease; align-items: stretch;
  }
  .nav-links.open { transform: translateY(0); }
  .nav-links a { padding: 12px 0; color: var(--ink) !important; border-bottom: 1px solid var(--line); }
  .nav-links .nav-cta { margin-top: 12px; border-bottom: 0; }
  .hamburger { display: flex; }
  .about-grid, .cards { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; gap: 36px; }
  .hero-stats { gap: 28px; }
  .section { padding: 64px 0; }
}