/* ===== 凯通电气 SEO改版 - 科技蓝风格 ===== */
:root {
  --primary: #0052CC;
  --primary-dark: #003D99;
  --primary-light: #4C9AFF;
  --accent: #00B8D9;
  --accent-light: #79E6FF;
  --bg-dark: #0A0E27;
  --bg-light: #F4F5F7;
  --bg-white: #FFFFFF;
  --text-dark: #172B4D;
  --text-light: #6B778C;
  --border: #DFE1E6;
  --gradient-blue: linear-gradient(135deg, #0052CC 0%, #003D99 100%);
  --gradient-tech: linear-gradient(135deg, #0A0E27 0%, #1A237E 100%);
  --shadow-sm: 0 2px 8px rgba(0, 82, 204, 0.1);
  --shadow-md: 0 4px 20px rgba(0, 82, 204, 0.15);
  --shadow-lg: 0 8px 40px rgba(0, 82, 204, 0.2);
  --radius: 12px;
  --transition: all 0.3s ease;
}

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

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--text-dark);
  line-height: 1.7;
  background: var(--bg-white);
  overflow-x: hidden;
}

/* ===== 导航栏 ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(10, 14, 39, 0.95);
  backdrop-filter: blur(20px);
  z-index: 1000;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.nav {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 40px;
  height: 72px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.logo-img {
  height: 42px;
  display: none !important;
}

.logo-text {
  color: #fff;
  font-size: 20px;
  font-weight: 700;
}

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

.nav-links {
  display: flex;
  gap: 8px;
  list-style: none;
}

.nav-links a {
  color: rgba(255,255,255,0.85);
  text-decoration: none;
  padding: 10px 20px;
  border-radius: 8px;
  font-size: 15px;
  transition: var(--transition);
}

.nav-links a:hover, .nav-links a.active {
  background: var(--primary);
  color: #fff;
}

.nav-phone {
  color: var(--accent-light);
  font-size: 18px;
  font-weight: 600;
  letter-spacing: 1px;
}

/* 手机菜单按钮 - 默认隐藏，PC端不显示 */
.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: #fff;
  font-size: 24px;
  cursor: pointer;
  margin-left: auto;
  margin-right: 8px;
}

/* 手机导航 - 默认隐藏 */
.mobile-nav {
  display: none;
  position: fixed;
  top: 72px;
  left: 0;
  right: 0;
  background: rgba(10, 14, 39, 0.98);
  backdrop-filter: blur(20px);
  z-index: 999;
  flex-direction: column;
  padding: 20px;
  border-top: 1px solid rgba(255,255,255,0.1);
}

.mobile-nav.open { display: flex; }

.mobile-nav a {
  color: rgba(255,255,255,0.85);
  text-decoration: none;
  padding: 14px 0;
  font-size: 16px;
  border-bottom: 1px solid rgba(255,255,255,0.1);
  display: block;
}

.mobile-nav a:last-child { border-bottom: none; }
.mobile-nav a.active, .mobile-nav a:hover { color: var(--accent-light); }

/* ===== 通用容器 ===== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.section { padding: 80px 0; }
.section-dark { background: var(--bg-dark); color: #fff; }

.section-title { text-align: center; margin-bottom: 60px; }
.section-title h2 { font-size: 36px; font-weight: 700; margin-bottom: 16px; }
.section-title p { color: var(--text-light); font-size: 16px; }
.section-dark .section-title p { color: rgba(255,255,255,0.6); }

.breadcrumb { padding: 100px 0 40px; background: var(--bg-light); }
.breadcrumb ul { max-width: 1200px; margin: 0 auto; padding: 0 20px; list-style: none; display: flex; align-items: center; gap: 8px; font-size: 14px; color: var(--text-light); }
.breadcrumb a { color: var(--primary); text-decoration: none; }
.breadcrumb a:hover { text-decoration: underline; }

/* ===== 按钮 ===== */
.btn { display: inline-block; padding: 14px 32px; border-radius: 8px; text-decoration: none; font-size: 15px; font-weight: 600; transition: var(--transition); cursor: pointer; border: none; }
.btn-primary { background: var(--gradient-blue); color: #fff; box-shadow: var(--shadow-md); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); }
.btn-outline { border: 2px solid var(--primary); color: var(--primary); background: transparent; }
.btn-outline:hover { background: var(--primary); color: #fff; }
.btn-white { background: #fff; color: var(--primary); }
.btn-white:hover { background: var(--bg-light); }

/* ===== 卡片 ===== */
.card { background: var(--bg-white); border-radius: var(--radius); box-shadow: var(--shadow-sm); overflow: hidden; transition: var(--transition); }
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }

/* ===== 页脚 ===== */
.footer { background: var(--bg-dark); color: rgba(255,255,255,0.8); padding: 60px 0 0; }
.footer-grid { max-width: 1200px; margin: 0 auto; padding: 0 20px; display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; }
.footer-brand h3 { color: #fff; font-size: 24px; margin-bottom: 16px; }
.footer-brand p { font-size: 14px; line-height: 1.8; margin-bottom: 20px; }
.footer h4 { color: #fff; font-size: 16px; margin-bottom: 20px; }
.footer ul { list-style: none; }
.footer ul li { margin-bottom: 10px; }
.footer ul a { color: rgba(255,255,255,0.7); text-decoration: none; font-size: 14px; transition: var(--transition); }
.footer ul a:hover { color: var(--accent-light); }
.footer-bottom { max-width: 1200px; margin: 40px auto 0; padding: 20px; border-top: 1px solid rgba(255,255,255,0.1); display: flex; justify-content: space-between; align-items: center; font-size: 14px; }
.footer-bottom a { color: rgba(255,255,255,0.6); text-decoration: none; }
.footer-bottom a:hover { color: var(--accent-light); }

/* ===== 响应式 ===== */
@media (max-width: 768px) {
  .logo-img { display: none !important; }
  .logo-text { font-size: 16px !important; }
  .nav { padding: 0 16px; }
  .nav-links { display: none !important; }
  .nav-phone { display: none !important; }
  .mobile-menu-btn { display: block !important; }
  .section { padding: 60px 0; }
  .section-title h2 { font-size: 28px; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; gap: 10px; text-align: center; }
  .news-grid { grid-template-columns: 1fr !important; }
}