/* ===== CSS Variables ===== */
:root {
  --primary: #1565C0;
  --primary-dark: #0D47A1;
  --primary-light: #1976D2;
  --accent: #FF6F00;
  --accent-light: #FFA000;
  --bg: #F5F7FA;
  --bg-white: #fff;
  --text: #1A1A2E;
  --text-muted: #555;
  --text-light: #888;
  --border: #E0E6F0;
  --shadow: 0 2px 16px rgba(21,101,192,0.10);
  --shadow-lg: 0 8px 40px rgba(21,101,192,0.16);
  --radius: 12px;
  --radius-sm: 8px;
  --nav-h: 68px;
  --font-main: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-en: 'Montserrat', var(--font-main);
}

/* ===== Reset ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font-main);
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
}
a { color: var(--primary); text-decoration: none; transition: color .2s; }
a:hover { color: var(--accent); }
img { max-width: 100%; display: block; }
ul { list-style: none; }

/* ===== Header / Nav ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-h);
  background: #fff;
  border-bottom: 1.5px solid var(--border);
  box-shadow: 0 2px 12px rgba(21,101,192,0.07);
  display: flex;
  align-items: center;
}
.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 0;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  flex-shrink: 0;
}
.nav-logo img { height: 38px; width: auto; }
.nav-logo-text {
  font-size: 1.18rem;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: .02em;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: 40px;
  flex: 1;
}
.nav-links a {
  font-size: 1.08rem;
  font-weight: 500;
  color: var(--text);
  padding: 8px 16px;
  border-radius: 8px;
  transition: background .2s, color .2s;
  white-space: nowrap;
}
.nav-links a:hover, .nav-links a.active {
  background: #E3F0FF;
  color: var(--primary);
}
.nav-cta {
  margin-left: auto;
  flex-shrink: 0;
}
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--primary);
  color: #fff !important;
  padding: 10px 24px;
  border-radius: 24px;
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: .03em;
  transition: background .2s, box-shadow .2s, transform .15s;
  cursor: pointer;
  border: none;
}
.btn-primary:hover {
  background: var(--accent);
  color: #fff !important;
  box-shadow: 0 4px 18px rgba(255,111,0,0.22);
  transform: translateY(-1px);
}
.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: transparent;
  color: var(--primary);
  padding: 10px 24px;
  border-radius: 24px;
  font-size: 1rem;
  font-weight: 600;
  border: 2px solid var(--primary);
  transition: all .2s;
  cursor: pointer;
}
.btn-outline:hover {
  background: var(--primary);
  color: #fff;
}
.btn-accent {
  background: var(--accent);
  color: #fff !important;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 36px;
  border-radius: 32px;
  font-size: 1.12rem;
  font-weight: 700;
  letter-spacing: .04em;
  transition: background .2s, box-shadow .2s, transform .15s;
  cursor: pointer;
  border: none;
  box-shadow: 0 4px 20px rgba(255,111,0,.25);
}
.btn-accent:hover {
  background: #e65100;
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(255,111,0,.35);
}

/* ===== Footer ===== */
.site-footer {
  background: #0D2545;
  color: #B0BFCF;
  padding: 56px 0 0;
  margin-top: 80px;
  font-size: .95rem;
}
.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px 40px;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
}
.footer-brand img { height: 36px; margin-bottom: 14px; filter: brightness(2); }
.footer-brand p { color: #8899aa; line-height: 1.8; max-width: 280px; font-size: .92rem; }
.footer-col h4 { color: #fff; font-size: 1rem; font-weight: 600; margin-bottom: 16px; }
.footer-col ul li { margin-bottom: 10px; }
.footer-col ul li a { color: #8899aa; transition: color .2s; }
.footer-col ul li a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid #1E3A5A;
  padding: 18px 24px;
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: .88rem;
  color: #556677;
}
.footer-bottom a { color: #556677; }
.footer-bottom a:hover { color: #8899aa; }

/* ===== Section Layout ===== */
.section { padding: 72px 0; }
.section-alt { background: #fff; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.section-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text);
  text-align: center;
  margin-bottom: 12px;
  line-height: 1.3;
}
.section-sub {
  text-align: center;
  color: var(--text-muted);
  font-size: 1.05rem;
  margin-bottom: 48px;
  max-width: 640px;
  margin-left: auto;
  margin-right: auto;
}
.section-tag {
  display: inline-block;
  background: #E3F0FF;
  color: var(--primary);
  padding: 4px 14px;
  border-radius: 20px;
  font-size: .85rem;
  font-weight: 600;
  margin-bottom: 14px;
  letter-spacing: .06em;
  text-transform: uppercase;
}

/* ===== Cards ===== */
.card-grid { display: grid; gap: 24px; }
.card-grid-2 { grid-template-columns: repeat(2, 1fr); }
.card-grid-3 { grid-template-columns: repeat(3, 1fr); }
.card-grid-4 { grid-template-columns: repeat(4, 1fr); }
.card {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 28px 24px;
  transition: box-shadow .25s, transform .2s;
  border: 1px solid var(--border);
}
.card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
}
.card-icon {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  font-size: 1.6rem;
  background: #E3F0FF;
  color: var(--primary);
}
.card h3 { font-size: 1.1rem; font-weight: 600; margin-bottom: 8px; }
.card p { color: var(--text-muted); font-size: .95rem; line-height: 1.7; }

/* ===== Mobile Menu ===== */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  font-size: 1.5rem;
  color: var(--text);
  margin-left: auto;
}

/* ===== Breadcrumb ===== */
.breadcrumb {
  padding: 14px 0;
  font-size: .9rem;
  color: var(--text-muted);
}
.breadcrumb a { color: var(--primary); }
.breadcrumb span { margin: 0 6px; color: #ccc; }

/* ===== Responsive ===== */
@media (max-width: 960px) {
  .card-grid-4 { grid-template-columns: repeat(2, 1fr); }
  .footer-inner { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  .nav-links { display: none; flex-direction: column; position: absolute; top: var(--nav-h); left: 0; right: 0; background: #fff; padding: 16px; border-bottom: 1px solid var(--border); z-index: 99; }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px 16px; width: 100%; }
  .nav-toggle { display: block; }
  .nav-cta { display: none; }
  .card-grid-3 { grid-template-columns: 1fr; }
  .card-grid-2 { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; }
  .section-title { font-size: 1.5rem; }
  .footer-bottom { flex-direction: column; gap: 8px; text-align: center; }
}