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

:root {
  --primary: #1a4f8b;      /* 工业蓝 */
  --primary-dark: #123a66;
  --accent: #e8a020;       /* 工具黄 */
  --dark: #1f2933;
  --gray: #52606d;
  --light: #f5f7fa;
  --border: #e4e9f0;
  --radius: 10px;
}

html { scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", Arial, sans-serif;
  color: var(--dark);
  background: #fff;
  line-height: 1.7;
}

.container { max-width: 1080px; margin: 0 auto; padding: 0 24px; }

/* ===== 顶部导航 ===== */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: #fff;
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 6px rgba(0,0,0,.05);
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 68px;
}
.logo { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.logo-mark {
  display: inline-flex; align-items: center; justify-content: center;
  width: 40px; height: 40px; border-radius: 8px;
  background: var(--primary); color: #fff;
  font-weight: 700; font-size: 16px; letter-spacing: 1px;
}
.logo-text { display: flex; flex-direction: column; line-height: 1.2; }
.logo-text strong { color: var(--dark); font-size: 17px; }
.logo-text small { color: var(--gray); font-size: 10px; letter-spacing: 1.5px; }

.site-nav { display: flex; gap: 28px; }
.site-nav a {
  color: var(--gray); text-decoration: none; font-size: 15px;
  padding: 6px 2px; border-bottom: 2px solid transparent;
  transition: color .2s, border-color .2s;
}
.site-nav a:hover { color: var(--primary); border-color: var(--accent); }

.nav-toggle {
  display: none; flex-direction: column; gap: 5px;
  background: none; border: none; cursor: pointer; padding: 6px;
}
.nav-toggle span {
  width: 22px; height: 2px; background: var(--dark); border-radius: 2px;
}

/* ===== 首屏 ===== */
.hero {
  background:
    linear-gradient(135deg, rgba(18,58,102,.92) 0%, rgba(26,79,139,.88) 55%, rgba(26,79,139,.8) 100%),
    repeating-linear-gradient(45deg, rgba(255,255,255,.04) 0 12px, transparent 12px 24px);
  color: #fff;
  padding: 96px 0 104px;
  text-align: center;
}
.hero-tag {
  display: inline-block;
  border: 1px solid rgba(255,255,255,.4);
  border-radius: 999px;
  padding: 5px 18px;
  font-size: 14px; letter-spacing: 2px;
  margin-bottom: 22px;
  color: rgba(255,255,255,.9);
}
.hero h1 { font-size: 40px; font-weight: 700; margin-bottom: 18px; letter-spacing: 1px; }
.hero-sub { max-width: 620px; margin: 0 auto 34px; font-size: 17px; color: rgba(255,255,255,.85); }
.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

.btn {
  display: inline-block; padding: 12px 32px; border-radius: 6px;
  font-size: 15px; text-decoration: none; transition: all .2s;
}
.btn-primary { background: var(--accent); color: #fff; font-weight: 600; }
.btn-primary:hover { background: #d18e14; }
.btn-outline { border: 1px solid rgba(255,255,255,.6); color: #fff; }
.btn-outline:hover { background: rgba(255,255,255,.12); }

/* ===== 通用区块 ===== */
.section { padding: 80px 0; }
.section-alt { background: var(--light); }
.section-head { text-align: center; margin-bottom: 48px; }
.section-head h2 { font-size: 30px; color: var(--dark); }
.section-sub {
  color: var(--accent); font-size: 13px; letter-spacing: 4px;
  text-transform: uppercase; margin-top: 6px;
}

/* ===== 公司简介 ===== */
.about-grid {
  display: grid; grid-template-columns: 1.5fr 1fr; gap: 48px; align-items: start;
}
.about-text p { margin-bottom: 16px; color: var(--gray); font-size: 16px; }
.about-text strong { color: var(--primary); }

.about-facts { display: flex; flex-direction: column; gap: 16px; }
.fact-card {
  background: #fff; border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius);
  padding: 20px 22px;
  box-shadow: 0 2px 8px rgba(0,0,0,.04);
}
.fact-num { display: block; font-size: 18px; font-weight: 700; color: var(--primary); margin-bottom: 4px; }
.fact-label { color: var(--gray); font-size: 14px; }

/* ===== 服务内容 ===== */
.service-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px;
}
.service-card {
  background: #fff; border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 24px;
  text-align: center;
  transition: transform .25s, box-shadow .25s;
}
.service-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 10px 24px rgba(0,0,0,.08);
}
.service-icon { font-size: 34px; margin-bottom: 14px; }
.service-card h3 { font-size: 17px; color: var(--dark); margin-bottom: 10px; }
.service-card p { font-size: 14px; color: var(--gray); }

/* ===== 联系方式 ===== */
.contact-grid {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px;
}
.contact-card {
  background: #fff; border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 26px;
  box-shadow: 0 2px 8px rgba(0,0,0,.04);
}
.contact-card h3 { font-size: 17px; color: var(--primary); margin-bottom: 10px; }
.contact-card p { font-size: 15px; color: var(--gray); }

.placeholder {
  background: #fff8e6;
  border: 1px dashed var(--accent);
  border-radius: 6px;
  padding: 10px 14px;
  color: #9a6b10 !important;
  font-size: 14px !important;
}
.contact-link {
  color: var(--primary);
  text-decoration: none;
  font-weight: 600;
  word-break: break-all;
}
.contact-link:hover { text-decoration: underline; }
.contact-note {
  margin-top: 32px; text-align: center; color: var(--gray); font-size: 15px;
}

/* ===== 页脚 ===== */
.site-footer {
  background: var(--dark); color: rgba(255,255,255,.75);
  padding: 36px 0; text-align: center; font-size: 14px;
}
.site-footer p { margin-bottom: 6px; }
.footer-note { font-size: 13px; color: rgba(255,255,255,.5); }
.footer-note a { color: rgba(255,255,255,.7); text-decoration: none; }
.footer-note a:hover { color: #fff; text-decoration: underline; }
.copyright { font-size: 12px; color: rgba(255,255,255,.4); margin-top: 10px !important; }

/* ===== 响应式 ===== */
@media (max-width: 900px) {
  .about-grid { grid-template-columns: 1fr; }
  .service-grid { grid-template-columns: repeat(2, 1fr); }
  .hero h1 { font-size: 30px; }
}
@media (max-width: 620px) {
  .service-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }

  .nav-toggle { display: flex; }
  .site-nav {
    display: none;
    position: absolute; top: 68px; left: 0; right: 0;
    background: #fff; flex-direction: column;
    padding: 16px 24px; gap: 8px;
    border-bottom: 1px solid var(--border);
    box-shadow: 0 8px 16px rgba(0,0,0,.08);
  }
  .site-nav.open { display: flex; }
  .site-nav a { padding: 10px 4px; }
}