/* ===== 全局 ===== */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  color: #333; line-height: 1.6; overflow-x: hidden;
}
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.section-padding { padding: 80px 0; }
.bg-light { background: #f8f9fa; }
.section-title {
  text-align: center; font-size: 32px; font-weight: 700;
  color: #1a3a5c; margin-bottom: 50px; position: relative;
}
.section-title::after {
  content: ''; display: block; width: 60px; height: 3px;
  background: #e87a2f; margin: 15px auto 0; border-radius: 2px;
}

/* ===== 导航栏 ===== */
.navbar {
  position: fixed; top: 0; left: 0; width: 100%; z-index: 1000;
  background: rgba(26,58,92,0.95); backdrop-filter: blur(10px);
  transition: all 0.3s;
}
.nav-container {
  display: flex; justify-content: space-between; align-items: center;
  height: 64px;
}
.nav-logo { text-decoration: none; display: flex; align-items: center; }
.nav-logo-img { height: 36px; width: auto; display: block; max-width: 180px; object-fit: contain; }
.nav-menu { display: flex; list-style: none; gap: 8px; }
.nav-link {
  color: rgba(255,255,255,0.85); text-decoration: none; padding: 8px 16px;
  font-size: 15px; transition: all 0.3s; position: relative;
  border-radius: 4px;
}
.nav-link::after {
  content: ''; position: absolute; bottom: 2px; left: 50%;
  width: 0; height: 2px; background: #e87a2f;
  transition: all 0.3s; transform: translateX(-50%);
}
.nav-link:hover { color: #fff; }
.nav-link:hover::after { width: 60%; }
.nav-link.active { color: #fff; }
.nav-link.active::after { width: 60%; }

.nav-toggle { display: none; background: none; border: none; color: #fff; font-size: 24px; cursor: pointer; }

/* ===== Hero / Banner（轮播） ===== */
.hero {
  position: relative; height: 100vh; min-height: 500px;
  display: flex; align-items: center; justify-content: center;
  overflow: hidden; padding-top: 64px;
}
.hero-carousel { position: absolute; inset: 0; }
.carousel-bg {
  position: absolute; inset: 0; background-size: cover; background-position: center;
  background-color: #1a3a5c; opacity: 0; transition: opacity 1.2s ease;
}
.carousel-bg.active { opacity: 1; }
.hero-overlay {
  position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba(26,58,92,0.85) 0%, rgba(26,58,92,0.6) 100%);
}
.hero-placeholder-tip {
  position: absolute; bottom: 20px; left: 50%; transform: translateX(-50%);
  background: rgba(255,255,255,0.9); color: #1a3a5c; padding: 4px 12px;
  border-radius: 4px; font-size: 12px; z-index: 2;
}
.hero-content { position: relative; z-index: 2; text-align: center; color: #fff; padding: 0 20px; }
.hero-title { font-size: 48px; font-weight: 800; margin-bottom: 16px; letter-spacing: 4px; }
.hero-subtitle { font-size: 20px; opacity: 0.9; margin-bottom: 36px; }
.hero-btns { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

.btn {
  display: inline-block; padding: 14px 36px; font-size: 16px; font-weight: 600;
  border-radius: 6px; text-decoration: none; cursor: pointer;
  border: none; transition: all 0.3s;
}
.btn-primary { background: #e87a2f; color: #fff; }
.btn-primary:hover { background: #d06a20; transform: translateY(-2px); box-shadow: 0 4px 15px rgba(232,122,47,0.4); }
.btn-secondary { background: transparent; color: #fff; border: 2px solid #fff; }
.btn-secondary:hover { background: rgba(255,255,255,0.1); transform: translateY(-2px); }

/* ===== 核心优势 ===== */
.advantages-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
.advantage-card {
  text-align: center; padding: 40px 24px; background: #fff;
  border-radius: 12px; box-shadow: 0 2px 12px rgba(0,0,0,0.06);
  transition: all 0.3s; cursor: default;
}
.advantage-card:hover { transform: translateY(-6px); box-shadow: 0 12px 30px rgba(0,0,0,0.1); }
.advantage-icon {
  width: 64px; height: 64px; margin: 0 auto 20px;
  background: linear-gradient(135deg, #1a3a5c, #2a5a8c);
  border-radius: 16px; display: flex; align-items: center; justify-content: center;
}
.advantage-icon i { font-size: 28px; color: #e87a2f; }
.advantage-card h3 { font-size: 20px; color: #1a3a5c; margin-bottom: 12px; }
.advantage-card p { font-size: 15px; color: #666; line-height: 1.8; }

/* ===== 品牌区 ===== */
.brand-section { background: linear-gradient(135deg, #1a3a5c 0%, #2a5a8c 100%); color: #fff; }
.brand-section .section-title { color: #fff; }
.brand-section .section-title::after { background: #e87a2f; }
.brand-content { display: flex; align-items: center; gap: 50px; }
.brand-text { flex: 1; }
.brand-text p { font-size: 16px; line-height: 1.8; opacity: 0.9; margin-bottom: 20px; }
.brand-feature { display: flex; align-items: flex-start; gap: 12px; font-size: 15px; opacity: 0.95; }
.brand-feature i { font-size: 24px; color: #e87a2f; margin-top: 2px; }
.brand-image { flex: 1; }

/* ===== 轮播 ===== */
.brand-carousel { flex: 1; position: relative; overflow: hidden; border-radius: 12px; }
.carousel-container { position: relative; width: 100%; height: 300px; overflow: hidden; }
.carousel-slide { position: absolute; inset: 0; opacity: 0; transition: opacity 0.6s ease; }
.carousel-slide.active { opacity: 1; }
.carousel-img-placeholder {
  width: 100%; height: 100%; background: rgba(255,255,255,0.15); border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  color: rgba(255,255,255,0.6); font-size: 14px; text-align: center; padding: 20px;
}
.carousel-btn {
  position: absolute; top: 50%; transform: translateY(-50%);
  width: 36px; height: 36px; border-radius: 50%; border: none;
  background: rgba(255,255,255,0.25); color: #fff; font-size: 14px;
  cursor: pointer; transition: all 0.3s; z-index: 5;
}
.carousel-btn:hover { background: rgba(255,255,255,0.5); }
.carousel-prev { left: 10px; }
.carousel-next { right: 10px; }
.carousel-dots { display: flex; justify-content: center; gap: 8px; margin-top: 12px; }
.dot {
  width: 10px; height: 10px; border-radius: 50%; background: rgba(255,255,255,0.3);
  cursor: pointer; transition: all 0.3s;
}
.dot.active { background: #e87a2f; }

/* ===== 关于我们 ===== */
.about-content { display: flex; align-items: center; gap: 50px; }
.about-image { flex: 1; }
.about-text { flex: 1.3; }
.about-text p { font-size: 16px; line-height: 1.9; color: #555; margin-bottom: 16px; }

/* ===== 核心业务 ===== */
.services-grid { display: grid; gap: 30px; }
.service-card {
  display: flex; background: #fff; border-radius: 12px; overflow: hidden;
  box-shadow: 0 2px 12px rgba(0,0,0,0.06); transition: all 0.3s;
}
.service-card:hover { transform: translateY(-4px); box-shadow: 0 8px 25px rgba(0,0,0,0.1); }
.service-card:nth-child(even) { flex-direction: row-reverse; }
.service-img { width: 40%; min-height: 220px; }
.service-info { flex: 1; padding: 32px; display: flex; flex-direction: column; justify-content: center; }
.service-info h3 { font-size: 20px; color: #1a3a5c; margin-bottom: 12px; }
.service-info p { font-size: 15px; color: #666; line-height: 1.8; }

/* ===== 运营案例 ===== */
.cases-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(340px, 1fr)); gap: 24px; }
.case-card {
  background: #fff; border-radius: 12px; overflow: hidden;
  box-shadow: 0 2px 12px rgba(0,0,0,0.06); transition: all 0.3s;
}
.case-card:hover { transform: translateY(-6px); box-shadow: 0 12px 30px rgba(0,0,0,0.12); }
.case-img { height: 160px; }
.case-info { padding: 20px; }
.case-info h3 { font-size: 17px; color: #1a3a5c; margin-bottom: 8px; }
.case-info p { font-size: 14px; color: #666; line-height: 1.7; }

/* ===== 联系我们 ===== */
.contact-content { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
.contact-form, .contact-info { background: #fff; padding: 36px; border-radius: 12px; box-shadow: 0 2px 12px rgba(0,0,0,0.06); }
.contact-form h3, .contact-info h3 { color: #1a3a5c; font-size: 20px; margin-bottom: 24px; }
.form-group { margin-bottom: 16px; }
.form-group label { display: block; font-size: 14px; color: #555; margin-bottom: 6px; font-weight: 500; }
.required { color: #e74c3c; }
.form-group input, .form-group textarea {
  width: 100%; padding: 10px 14px; border: 1px solid #ddd; border-radius: 6px;
  font-size: 15px; transition: border-color 0.3s; font-family: inherit;
}
.form-group input:focus, .form-group textarea:focus { outline: none; border-color: #e87a2f; }
.btn-submit { width: 100%; margin-top: 8px; }
.info-items { display: flex; flex-direction: column; gap: 20px; }
.info-item { display: flex; align-items: flex-start; gap: 14px; }
.info-item i { font-size: 20px; color: #e87a2f; margin-top: 2px; width: 24px; text-align: center; }
.info-label { display: block; font-size: 13px; color: #999; }
.info-value { display: block; font-size: 15px; color: #333; }

/* ===== 页脚 ===== */
.footer {
  background: #1a3a5c; color: rgba(255,255,255,0.7); text-align: center;
  padding: 24px 0; font-size: 14px;
}

/* ===== 图片占位 ===== */
.img-placeholder {
  width: 100%; height: 280px; background: #e8ecf1; border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  color: #999; font-size: 14px; text-align: center; padding: 20px;
}
.img-placeholder-sm {
  width: 100%; height: 100%; background: #e8ecf1; border-radius: 0;
  display: flex; align-items: center; justify-content: center;
  color: #999; font-size: 13px;
}

/* ===== 弹窗 ===== */
.modal-overlay {
  display: none; position: fixed; inset: 0; background: rgba(0,0,0,0.5);
  z-index: 2000; align-items: center; justify-content: center;
}
.modal-overlay.active { display: flex; }
.modal-box {
  background: #fff; padding: 40px; border-radius: 16px; text-align: center;
  max-width: 400px; width: 90%; animation: modalIn 0.3s;
}
@keyframes modalIn { from { transform: scale(0.9); opacity: 0; } to { transform: scale(1); opacity: 1; } }
.modal-icon { font-size: 48px; color: #27ae60; margin-bottom: 16px; }
.modal-text { font-size: 16px; color: #333; margin-bottom: 24px; }

/* ===== 响应式 ===== */
@media (max-width: 768px) {
  .nav-menu { display: none; position: absolute; top: 64px; left: 0; width: 100%;
    background: rgba(26,58,92,0.98); flex-direction: column; padding: 16px; gap: 4px; }
  .nav-menu.active { display: flex; }
  .nav-toggle { display: block; }
  .hero-title { font-size: 32px; }
  .hero-subtitle { font-size: 16px; }
  .advantages-grid { grid-template-columns: 1fr; }
  .brand-content { flex-direction: column; }
  .brand-carousel { width: 100%; }
  .carousel-container { height: 200px; }
  .about-content { flex-direction: column-reverse; }
  .about-image { width: 100%; }
  .about-image .img-placeholder { height: 260px; width: 100%; min-height: 200px; }
  .service-img { width: 100%; }
  .service-img .img-placeholder { height: 220px; min-height: 180px; width: 100%; }
  .service-card { flex-direction: column !important; }
  .service-img { width: 100%; min-height: 180px; }
  .contact-content { grid-template-columns: 1fr; }
  .section-title { font-size: 26px; }
  .cases-grid { grid-template-columns: 1fr; }
  .section-padding { padding: 50px 0; }
}