/* ============================================
   佐白电气官网 - 公共样式
   工业蓝 + 白，B2B 专业风格
   ============================================ */

:root {
  --primary: #1a4f8b;
  --primary-dark: #123a66;
  --primary-light: #e8f0f9;
  --accent: #e6a817;
  --text: #2b3440;
  --text-light: #5b6b7c;
  --bg: #ffffff;
  --bg-gray: #f5f7fa;
  --border: #e2e8f0;
  --radius: 8px;
  --shadow: 0 4px 20px rgba(26, 79, 139, 0.08);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: "Microsoft YaHei", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  font-size: 16px;
}

a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-dark); }

.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* ---------- 顶部导航 ---------- */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 2px 8px rgba(0,0,0,0.04);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 20px; color: var(--primary); }
.logo-mark {
  width: 36px; height: 36px; border-radius: 6px;
  background: var(--primary); color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 16px; font-weight: 800;
}

.nav-links { display: flex; align-items: center; gap: 28px; }
.nav-links a { color: var(--text); font-size: 15px; }
.nav-links a:hover, .nav-links a.active { color: var(--primary); font-weight: 600; }

.nav-phone {
  display: flex; align-items: center; gap: 8px;
  background: var(--primary); color: #fff !important;
  padding: 8px 18px; border-radius: 20px; font-weight: 600; font-size: 14px;
}
.nav-phone:hover { background: var(--primary-dark); }

.menu-toggle { display: none; background: none; border: none; font-size: 24px; cursor: pointer; color: var(--text); }

/* ---------- 首屏 Hero ---------- */
.hero {
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 60%, #2a6cb5 100%);
  color: #fff;
  padding: 88px 0 80px;
  position: relative;
  overflow: hidden;
}
.hero::after {
  content: "";
  position: absolute; right: -120px; top: -120px;
  width: 420px; height: 420px; border-radius: 50%;
  background: rgba(255,255,255,0.06);
}
.hero .container { position: relative; z-index: 2; }

.hero h1 { font-size: 40px; line-height: 1.35; margin-bottom: 18px; }
.hero p { font-size: 18px; color: rgba(255,255,255,0.88); max-width: 640px; margin-bottom: 36px; }

.btn-group { display: flex; gap: 16px; flex-wrap: wrap; }
.btn {
  display: inline-block; padding: 12px 32px; border-radius: 6px;
  font-size: 16px; font-weight: 600; transition: all 0.25s; cursor: pointer; border: none;
}
.btn-primary { background: var(--accent); color: #1a2b3c; }
.btn-primary:hover { background: #f0b932; color: #1a2b3c; transform: translateY(-2px); }
.btn-outline { background: transparent; color: #fff; border: 2px solid rgba(255,255,255,0.6); }
.btn-outline:hover { border-color: #fff; background: rgba(255,255,255,0.1); }

/* ---------- 业务板块 ---------- */
.section { padding: 72px 0; }
.section-gray { background: var(--bg-gray); }

.section-title { text-align: center; font-size: 30px; color: var(--text); margin-bottom: 12px; }
.section-sub { text-align: center; color: var(--text-light); font-size: 16px; margin-bottom: 48px; }

.biz-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.biz-card {
  background: var(--bg); border-radius: var(--radius); border: 1px solid var(--border);
  padding: 32px 26px; transition: all 0.3s; box-shadow: var(--shadow);
}
.biz-card:hover { transform: translateY(-6px); box-shadow: 0 12px 32px rgba(26,79,139,0.15); }
.biz-icon {
  width: 52px; height: 52px; border-radius: 12px; background: var(--primary-light);
  display: flex; align-items: center; justify-content: center; font-size: 26px; margin-bottom: 18px;
}
.biz-card h3 { font-size: 20px; margin-bottom: 10px; }
.biz-card p { color: var(--text-light); font-size: 14.5px; }
.biz-card .biz-more { display: inline-block; margin-top: 14px; font-size: 14px; font-weight: 600; }

/* ---------- 数据条 ---------- */
.stats {
  background: var(--primary); color: #fff; padding: 48px 0;
}
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; text-align: center; }
.stats-num { font-size: 36px; font-weight: 800; }
.stats-label { font-size: 14px; color: rgba(255,255,255,0.8); margin-top: 4px; }

/* ---------- 案例 ---------- */
.case-card {
  display: grid; grid-template-columns: 1.2fr 1fr; gap: 32px; align-items: center;
  background: var(--bg); border-radius: var(--radius); border: 1px solid var(--border);
  padding: 36px; box-shadow: var(--shadow);
}
.case-img {
  background: linear-gradient(135deg, #1a4f8b, #2a6cb5); color: #fff;
  height: 260px; border-radius: var(--radius); display: flex; align-items: center; justify-content: center;
  font-size: 60px;
}
.case-info h3 { font-size: 24px; margin-bottom: 14px; color: var(--primary); }
.case-info ul { list-style: none; margin-bottom: 18px; }
.case-info ul li { padding: 6px 0; border-bottom: 1px dashed var(--border); font-size: 15px; }
.case-info ul li span { color: var(--text-light); }
.case-tag {
  display: inline-block; background: var(--primary-light); color: var(--primary);
  font-size: 13px; padding: 4px 12px; border-radius: 14px; margin: 2px 4px 2px 0; font-weight: 600;
}

/* ---------- 优势 ---------- */
.adv-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.adv-item { text-align: center; padding: 24px 16px; }
.adv-icon { font-size: 38px; margin-bottom: 12px; }
.adv-item h4 { font-size: 17px; margin-bottom: 8px; }
.adv-item p { color: var(--text-light); font-size: 14px; }

/* ---------- 文章 ---------- */
.article-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.article-card {
  background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 24px; transition: all 0.3s; box-shadow: var(--shadow);
}
.article-card:hover { transform: translateY(-4px); }
.article-date { font-size: 13px; color: var(--text-light); margin-bottom: 8px; }
.article-card h4 { font-size: 16px; line-height: 1.5; margin-bottom: 8px; }
.article-card p { font-size: 14px; color: var(--text-light); }

/* ---------- 页脚 ---------- */
.footer { background: #16233a; color: rgba(255,255,255,0.7); padding: 48px 0 24px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 32px; margin-bottom: 32px; }
.footer h4 { color: #fff; font-size: 16px; margin-bottom: 14px; }
.footer a { color: rgba(255,255,255,0.7); display: block; margin-bottom: 8px; font-size: 14px; }
.footer a:hover { color: #fff; }
.footer-company { font-size: 15px; color: #fff; font-weight: 600; margin-bottom: 8px; }
.footer-copy { border-top: 1px solid rgba(255,255,255,0.12); padding-top: 20px; text-align: center; font-size: 13px; }

/* ---------- 内页通用 ---------- */
.page-hero {
  background: linear-gradient(135deg, var(--primary-dark), var(--primary));
  color: #fff; padding: 56px 0 48px; text-align: center;
}
.page-hero h1 { font-size: 32px; margin-bottom: 8px; }
.page-hero p { color: rgba(255,255,255,0.85); font-size: 16px; }

/* 产品页 */
.product-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.product-card { background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius); padding: 28px; box-shadow: var(--shadow); }
.product-card h3 { color: var(--primary); font-size: 20px; margin-bottom: 12px; }
.product-card .model { display: inline-block; background: var(--primary-light); color: var(--primary); padding: 3px 12px; border-radius: 12px; font-size: 13px; font-weight: 600; margin-bottom: 10px; }
.product-card p { color: var(--text-light); font-size: 14.5px; margin-bottom: 12px; }
.param-table { width: 100%; border-collapse: collapse; font-size: 14px; }
.param-table th, .param-table td { border: 1px solid var(--border); padding: 8px 12px; text-align: left; }
.param-table th { background: var(--bg-gray); color: var(--text); width: 38%; font-weight: 600; }

/* 案例页 */
.case-full { background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius); padding: 36px; box-shadow: var(--shadow); margin-bottom: 24px; }
.case-full h2 { color: var(--primary); font-size: 22px; margin-bottom: 16px; }
.case-full h3 { font-size: 17px; margin: 18px 0 10px; }
.case-full p { color: var(--text); margin-bottom: 10px; }
.case-full ul { padding-left: 20px; }
.case-full li { margin-bottom: 6px; }

/* 联系页 */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 32px; }
.contact-card { background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius); padding: 32px; box-shadow: var(--shadow); }
.contact-card h3 { color: var(--primary); font-size: 20px; margin-bottom: 16px; }
.contact-item { display: flex; align-items: center; gap: 12px; padding: 12px 0; border-bottom: 1px dashed var(--border); font-size: 16px; }
.contact-item:last-child { border-bottom: none; }
.contact-emoji { font-size: 22px; }

/* 响应式 */
@media (max-width: 900px) {
  .biz-grid, .adv-grid, .article-grid { grid-template-columns: 1fr; }
  .product-grid, .contact-grid { grid-template-columns: 1fr; }
  .case-card { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }
  .footer-grid { grid-template-columns: 1fr; gap: 24px; }
  .hero h1 { font-size: 30px; }
  .nav-links {
    display: none; position: absolute; top: 68px; left: 0; right: 0;
    background: var(--bg); flex-direction: column; padding: 16px 24px;
    border-bottom: 1px solid var(--border); gap: 16px;
  }
  .nav-links.open { display: flex; }
  .menu-toggle { display: block; }
}