/* ===== 全局样式 ===== */
:root {
  --primary: #1a3a5c;
  --primary-light: #2a5a8c;
  --accent: #4a90d9;
  --accent2: #2ecc71;
  --text: #333;
  --text-light: #666;
  --bg: #fff;
  --bg-gray: #f8f9fa;
  --border: #e8ecf0;
  --shadow: 0 2px 12px rgba(26,58,92,0.08);
  --radius: 8px;
  --transition: all 0.3s ease;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: 'Microsoft YaHei', 'PingFang SC', 'Helvetica Neue', sans-serif;
  color: var(--text);
  line-height: 1.7;
  background: var(--bg);
}

a { color: var(--accent); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--primary-light); }

img { max-width: 100%; height: auto; }

.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

/* ===== Header & Navigation ===== */
.header {
  position: fixed; top: 0; left: 0; right: 0;
  background: rgba(255,255,255,0.97);
  backdrop-filter: blur(10px);
  box-shadow: 0 1px 4px rgba(0,0,0,0.06);
  z-index: 1000;
  transition: var(--transition);
}

.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 70px; max-width: 1200px; margin: 0 auto; padding: 0 20px;
}

.logo {
  display: flex; align-items: center; gap: 10px;
  font-size: 22px; font-weight: 700; color: var(--primary);
}

.logo span { color: var(--accent); }

.logo-icon {
  width: 36px; height: 36px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
  color: #fff; font-size: 18px; font-weight: bold;
}

.nav { display: flex; align-items: center; gap: 32px; }

.nav a {
  color: var(--text); font-size: 15px; font-weight: 500;
  position: relative; padding: 4px 0;
}

.nav a::after {
  content: ''; position: absolute; bottom: -2px; left: 0; right: 0;
  height: 2px; background: var(--accent);
  transform: scaleX(0); transition: transform 0.3s ease;
}

.nav a:hover::after,
.nav a.active::after { transform: scaleX(1); }
.nav a.active { color: var(--accent); }

.menu-toggle { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 5px; }
.menu-toggle span {
  width: 26px; height: 2px; background: var(--primary);
  transition: var(--transition);
}

/* ===== Hero / Banner ===== */
.hero {
  margin-top: 70px;
  position: relative; overflow: hidden;
  height: 520px;
}

.hero-slider { position: relative; height: 100%; }

.hero-slide {
  position: absolute; top: 0; left: 0; width: 100%; height: 100%;
  opacity: 0; transition: opacity 0.8s ease;
  display: flex; align-items: center; justify-content: center;
}

.hero-slide.active { opacity: 1; }

.hero-bg {
  position: absolute; top: 0; left: 0; width: 100%; height: 100%;
  background: linear-gradient(135deg, var(--primary), #0d2137);
}

.hero-pattern {
  position: absolute; top: 0; left: 0; width: 100%; height: 100%;
  background-image:
    radial-gradient(circle at 20% 50%, rgba(74,144,217,0.15) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(46,204,113,0.1) 0%, transparent 50%);
}

.hero-content {
  position: relative; z-index: 2; text-align: center; color: #fff;
  padding: 0 20px; max-width: 800px;
}

.hero-content h1 { font-size: 44px; font-weight: 700; margin-bottom: 16px; letter-spacing: 2px; }
.hero-content p { font-size: 20px; opacity: 0.85; margin-bottom: 30px; }
.hero-btn {
  display: inline-block; padding: 14px 36px;
  background: var(--accent); color: #fff; border-radius: 50px;
  font-size: 16px; font-weight: 600;
  transition: var(--transition); border: none; cursor: pointer;
}
.hero-btn:hover { background: var(--primary-light); transform: translateY(-2px); color: #fff; }

.hero-dots {
  position: absolute; bottom: 30px; left: 50%; transform: translateX(-50%);
  display: flex; gap: 8px; z-index: 3;
}
.hero-dots span {
  width: 10px; height: 10px; border-radius: 50%;
  background: rgba(255,255,255,0.4); cursor: pointer;
  transition: var(--transition);
}
.hero-dots span.active { background: #fff; width: 28px; border-radius: 5px; }

/* ===== Section Common ===== */
.section { padding: 80px 0; }
.section-gray { background: var(--bg-gray); }
.section-title {
  text-align: center; margin-bottom: 50px;
}
.section-title h2 {
  font-size: 32px; color: var(--primary); font-weight: 700;
  position: relative; display: inline-block;
}
.section-title h2::after {
  content: ''; display: block; width: 50px; height: 3px;
  background: var(--accent); margin: 12px auto 0;
  border-radius: 2px;
}
.section-title p { color: var(--text-light); margin-top: 12px; font-size: 16px; }

/* ===== About ===== */
.about-content { display: flex; gap: 50px; align-items: center; }
.about-text { flex: 1; }
.about-text p { font-size: 16px; line-height: 1.8; color: var(--text-light); margin-bottom: 20px; }
.about-image { flex: 1; }
.about-image-placeholder {
  width: 100%; height: 350px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: var(--radius); display: flex;
  align-items: center; justify-content: center;
  color: #fff; font-size: 48px;
}

/* ===== Advantages ===== */
.advantages-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.advantage-card {
  text-align: center; padding: 40px 20px;
  background: #fff; border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: var(--transition);
}
.advantage-card:hover { transform: translateY(-5px); box-shadow: 0 8px 24px rgba(26,58,92,0.12); }
.advantage-icon { font-size: 48px; margin-bottom: 16px; display: block; }
.advantage-card h3 { font-size: 20px; color: var(--primary); margin-bottom: 10px; }
.advantage-card p { font-size: 14px; color: var(--text-light); line-height: 1.6; }

/* ===== Grid Cards ===== */
.card-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.card-item {
  background: #fff; border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow); transition: var(--transition);
}
.card-item:hover { transform: translateY(-4px); box-shadow: 0 8px 24px rgba(26,58,92,0.1); }
.card-image {
  height: 200px; background: var(--border);
  display: flex; align-items: center; justify-content: center;
  font-size: 48px; color: var(--primary-light);
}
.card-body { padding: 20px 24px; }
.card-body h3 { font-size: 18px; color: var(--primary); margin-bottom: 8px; }
.card-body .meta { font-size: 13px; color: var(--text-light); margin-bottom: 8px; }
.card-body p { font-size: 14px; color: var(--text-light); line-height: 1.6; }
.card-body .btn-text {
  display: inline-block; margin-top: 12px;
  color: var(--accent); font-weight: 600; font-size: 14px;
}
.card-body .btn-text:hover { color: var(--primary-light); }

/* ===== Page Banner ===== */
.page-banner {
  margin-top: 70px; padding: 80px 0;
  background: linear-gradient(135deg, var(--primary), #0d2137);
  text-align: center; color: #fff;
  position: relative; overflow: hidden;
}
.page-banner::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; bottom: 0;
  background: radial-gradient(circle at 80% 30%, rgba(74,144,217,0.2) 0%, transparent 60%);
}
.page-banner h1 { font-size: 36px; font-weight: 700; position: relative; z-index: 1; }
.page-banner p { font-size: 16px; opacity: 0.8; margin-top: 10px; position: relative; z-index: 1; }

/* ===== Timeline ===== */
.timeline { position: relative; max-width: 800px; margin: 0 auto; padding: 20px 0; }
.timeline::before {
  content: ''; position: absolute; left: 50%; transform: translateX(-50%);
  width: 2px; height: 100%; background: var(--border); top: 0;
}
.timeline-item {
  position: relative; margin-bottom: 40px;
  display: flex; align-items: flex-start;
}
.timeline-item:nth-child(odd) { flex-direction: row; }
.timeline-item:nth-child(even) { flex-direction: row-reverse; }
.timeline-dot {
  position: absolute; left: 50%; transform: translateX(-50%);
  width: 16px; height: 16px;
  background: var(--accent); border-radius: 50%;
  border: 3px solid #fff; box-shadow: 0 0 0 2px var(--accent);
  z-index: 2; top: 6px;
}
.timeline-content {
  width: calc(50% - 40px); padding: 20px;
  background: #fff; border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: var(--transition);
}
.timeline-item:nth-child(odd) .timeline-content { margin-left: auto; }
.timeline-item:nth-child(even) .timeline-content { margin-right: auto; }
.timeline-content:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(26,58,92,0.1); }
.timeline-year {
  display: inline-block; padding: 2px 14px;
  background: var(--accent); color: #fff; border-radius: 20px;
  font-size: 14px; font-weight: 600; margin-bottom: 8px;
}
.timeline-content h3 { font-size: 18px; color: var(--primary); margin-bottom: 8px; }
.timeline-content p { font-size: 14px; color: var(--text-light); }

/* ===== Detail Page ===== */
.detail-wrapper { max-width: 860px; margin: 0 auto; padding: 40px 0; }
.detail-header { margin-bottom: 30px; }
.detail-header h1 { font-size: 28px; color: var(--primary); margin-bottom: 12px; }
.detail-header .meta { color: var(--text-light); font-size: 14px; }
.detail-content { font-size: 16px; line-height: 1.9; color: var(--text); }
.detail-content h3 { color: var(--primary); margin: 24px 0 12px; font-size: 20px; }
.detail-content ul { margin: 12px 0; padding-left: 24px; }
.detail-content li { margin-bottom: 8px; }
.detail-nav {
  display: flex; justify-content: space-between;
  margin-top: 40px; padding-top: 24px;
  border-top: 1px solid var(--border);
}
.detail-nav a { font-size: 15px; }

/* ===== Contact ===== */
.contact-wrapper { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; }
.contact-info h3 { font-size: 22px; color: var(--primary); margin-bottom: 20px; }
.contact-item { display: flex; gap: 14px; margin-bottom: 20px; align-items: flex-start; }
.contact-icon { font-size: 22px; width: 40px; text-align: center; }
.contact-item-text h4 { font-size: 15px; color: var(--primary); margin-bottom: 2px; }
.contact-item-text p { color: var(--text-light); font-size: 14px; }
.contact-form { }
.form-group { margin-bottom: 16px; }
.form-group label { display: block; margin-bottom: 6px; font-size: 14px; font-weight: 600; color: var(--text); }
.form-group input,
.form-group textarea,
.form-group select {
  width: 100%; padding: 12px 16px;
  border: 1px solid var(--border); border-radius: 6px;
  font-size: 15px; font-family: inherit; transition: var(--transition);
}
.form-group input:focus,
.form-group textarea:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(74,144,217,0.15); }
.form-group textarea { height: 120px; resize: vertical; }
.btn-submit {
  padding: 14px 36px; background: var(--primary); color: #fff;
  border: none; border-radius: 6px; font-size: 16px; font-weight: 600;
  cursor: pointer; transition: var(--transition);
}
.btn-submit:hover { background: var(--primary-light); transform: translateY(-2px); }

/* ===== Pagination ===== */
.pagination { display: flex; justify-content: center; gap: 8px; margin-top: 40px; }
.pagination a, .pagination span {
  display: flex; align-items: center; justify-content: center;
  width: 40px; height: 40px;
  border-radius: 6px; font-size: 14px;
  border: 1px solid var(--border); color: var(--text);
  transition: var(--transition);
}
.pagination a:hover { border-color: var(--accent); color: var(--accent); }
.pagination .active { background: var(--accent); color: #fff; border-color: var(--accent); }

/* ===== Footer ===== */
.footer {
  background: var(--primary); color: rgba(255,255,255,0.8);
  padding: 50px 0 20px;
}
.footer-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px; margin-bottom: 30px; }
.footer h4 { color: #fff; font-size: 18px; margin-bottom: 16px; }
.footer p, .footer a { font-size: 14px; line-height: 2; color: rgba(255,255,255,0.7); }
.footer a:hover { color: #fff; }
.footer-bottom { text-align: center; padding-top: 20px; border-top: 1px solid rgba(255,255,255,0.1); font-size: 13px; }

/* ===== Success Alert ===== */
.alert-success {
  padding: 14px 20px; background: #d4edda; color: #155724;
  border-radius: 6px; margin-bottom: 20px; font-size: 15px;
}

/* ===== Responsive ===== */
@media (max-width: 992px) {
  .advantages-grid { grid-template-columns: repeat(2, 1fr); }
  .card-grid { grid-template-columns: repeat(2, 1fr); }
  .about-content { flex-direction: column; }
  .contact-wrapper { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .menu-toggle { display: flex; }
  .nav {
    position: fixed; top: 70px; left: 0; right: 0;
    background: #fff; flex-direction: column;
    padding: 20px; gap: 16px; box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    transform: translateY(-100%); opacity: 0; pointer-events: none;
    transition: var(--transition);
  }
  .nav.open { transform: translateY(0); opacity: 1; pointer-events: all; }

  .hero-content h1 { font-size: 28px; }
  .hero-content p { font-size: 16px; }
  .hero { height: 380px; }

  .advantages-grid { grid-template-columns: 1fr; }
  .card-grid { grid-template-columns: 1fr; }
  .section { padding: 50px 0; }
  .section-title h2 { font-size: 26px; }

  .timeline::before { left: 20px; }
  .timeline-item, .timeline-item:nth-child(even) { flex-direction: row !important; }
  .timeline-dot { left: 20px; }
  .timeline-content { width: calc(100% - 50px); }
  .timeline-item:nth-child(odd) .timeline-content,
  .timeline-item:nth-child(even) .timeline-content { margin-left: 50px; margin-right: 0; }

  .footer-grid { grid-template-columns: 1fr; }
  .page-banner { padding: 50px 0; }
  .page-banner h1 { font-size: 28px; }
}