:root {
  --primary: #1e3a8a;
  --primary-light: #3b82f6;
  --accent: #f59e0b;
  --bg: #ffffff;
  --bg-alt: #f5f7fb;
  --text: #1f2937;
  --text-soft: #5b6573;
  --border: #e5e9f2;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(30, 58, 138, 0.08);
  --max-width: 1140px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

.container { width: 100%; max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }

a { text-decoration: none; color: inherit; }

/* 导航栏 */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  transition: box-shadow .3s;
}
.nav-inner { 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: 10px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: #fff; display: grid; place-items: center; font-size: 18px;
}
.nav-menu { display: flex; gap: 28px; }
.nav-menu a { color: var(--text-soft); font-weight: 500; transition: color .2s; }
.nav-menu a:hover { color: var(--primary); }
.nav-toggle { display: none; background: none; border: none; font-size: 24px; color: var(--primary); cursor: pointer; }

/* Hero */
.hero { position: relative; padding: 160px 0 100px; overflow: hidden; }
.hero-bg {
  position: absolute; inset: 0;
  background:
    radial-gradient(800px 400px at 80% -10%, rgba(59, 130, 246, 0.18), transparent),
    radial-gradient(600px 400px at 0% 20%, rgba(30, 58, 138, 0.12), transparent),
    linear-gradient(180deg, #f7f9ff, #ffffff);
}
.hero-content { position: relative; text-align: center; }
.hero-eyebrow { letter-spacing: 4px; color: var(--primary-light); font-size: 13px; font-weight: 600; }
.hero-title { font-size: 52px; font-weight: 800; margin: 18px 0; color: var(--primary); }
.hero-sub { max-width: 640px; margin: 0 auto; color: var(--text-soft); font-size: 18px; }
.hero-actions { margin: 36px 0 56px; display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn { display: inline-block; padding: 13px 30px; border-radius: 999px; font-weight: 600; transition: transform .2s, box-shadow .2s, background .2s; }
.btn-primary { background: var(--primary); color: #fff; box-shadow: 0 8px 20px rgba(30,58,138,.25); }
.btn-primary:hover { transform: translateY(-2px); background: #16307a; }
.btn-ghost { border: 1.5px solid var(--primary); color: var(--primary); }
.btn-ghost:hover { background: rgba(30,58,138,.06); }

.hero-stats { display: flex; gap: 40px; justify-content: center; flex-wrap: wrap; }
.stat { text-align: center; }
.stat .num { display: block; font-size: 38px; font-weight: 800; color: var(--primary); }
.stat .label { color: var(--text-soft); font-size: 14px; }

/* Section */
.section { padding: 90px 0; }
.section-alt { background: var(--bg-alt); }
.section-head { text-align: center; margin-bottom: 50px; }
.section-tag {
  display: inline-block; padding: 5px 14px; border-radius: 999px;
  background: rgba(59,130,246,.12); color: var(--primary-light);
  font-size: 13px; font-weight: 600; letter-spacing: 1px;
}
.section-head h2 { font-size: 32px; margin-top: 14px; color: var(--text); }

/* 关于我们 */
.about-grid { display: grid; grid-template-columns: 1.3fr 1fr; gap: 48px; align-items: start; }
.about-text p { color: var(--text-soft); margin-bottom: 18px; }
.about-list { list-style: none; margin-top: 10px; }
.about-list li { margin: 12px 0; color: var(--text-soft); }
.about-list strong { color: var(--primary); margin-right: 6px; }
.about-card { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 30px; box-shadow: var(--shadow); }
.about-card h3 { margin-bottom: 18px; color: var(--primary); }
.feature-row { display: flex; gap: 14px; margin-bottom: 18px; }
.feature-row .dot { flex: none; width: 12px; height: 12px; margin-top: 8px; border-radius: 50%; background: var(--accent); }
.feature-row p { color: var(--text-soft); font-size: 14px; }

/* 卡片 */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.card {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 30px; box-shadow: var(--shadow); transition: transform .25s, box-shadow .25s;
}
.card:hover { transform: translateY(-6px); box-shadow: 0 18px 40px rgba(30,58,138,.14); }
.card-icon { font-size: 34px; margin-bottom: 14px; }
.card h3 { margin-bottom: 10px; color: var(--primary); }
.card p { color: var(--text-soft); font-size: 15px; }

/* 技术优势 */
.adv-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.adv-item { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 26px; }
.adv-item b { color: var(--primary); font-size: 17px; }
.adv-item p { color: var(--text-soft); font-size: 14px; margin-top: 8px; }

/* 新闻 */
.news-list { display: flex; flex-direction: column; gap: 16px; max-width: 820px; margin: 0 auto; }
.news-item {
  display: flex; gap: 24px; align-items: center; background: #fff;
  border: 1px solid var(--border); border-radius: var(--radius); padding: 22px 26px;
  transition: transform .2s, box-shadow .2s;
}
.news-item:hover { transform: translateX(4px); box-shadow: var(--shadow); }
.news-date { flex: none; font-weight: 700; color: var(--primary-light); min-width: 70px; }
.news-body h4 { color: var(--text); margin-bottom: 4px; }
.news-body p { color: var(--text-soft); font-size: 14px; }

/* 联系 */
.contact-grid { display: flex; justify-content: center; }
.contact-form { width: 100%; max-width: 640px; background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 32px; box-shadow: var(--shadow); }
.field { margin-bottom: 18px; }
.field label { display: block; font-weight: 600; margin-bottom: 8px; color: var(--text); }
.field input, .field textarea {
  width: 100%; padding: 12px 14px; border: 1px solid var(--border); border-radius: 10px;
  font-size: 15px; font-family: inherit; color: var(--text); resize: vertical;
}
.field input:focus, .field textarea:focus { outline: none; border-color: var(--primary-light); }
.form-hint { color: var(--text-soft); font-size: 13px; margin-top: 12px; }

/* 页脚 */
.footer { background: #0f1c44; color: #fff; padding: 34px 0; }
.footer-inner { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 14px; }
.footer-brand { display: flex; align-items: center; gap: 10px; font-weight: 700; }
.footer-copy { opacity: .85; font-size: 14px; }
.footer-copy p { margin: 2px 0; }
.beian { margin-top: 6px; }
.beian a { color: #c7d2fe; text-decoration: none; border-bottom: 1px dashed rgba(199,210,254,.5); }
.beian a:hover { color: #fff; border-bottom-color: #fff; }

/* 响应式 */
@media (max-width: 860px) {
  .nav-menu {
    position: absolute; top: 68px; left: 0; right: 0; flex-direction: column; gap: 0;
    background: #fff; border-bottom: 1px solid var(--border); display: none;
  }
  .nav-menu.open { display: flex; }
  .nav-menu a { padding: 14px 24px; border-top: 1px solid var(--border); }
  .nav-toggle { display: block; }
  .hero-title { font-size: 38px; }
  .about-grid { grid-template-columns: 1fr; }
  .cards, .adv-grid { grid-template-columns: 1fr; }
  .hero-stats { gap: 26px; }
}