/* ============================================
   京铁导航官方网站 - 公共样式
   ============================================ */
* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --primary: #0b6cff;
  --primary-dark: #0853c2;
  --primary-light: #e8f1ff;
  --text-main: #1f2d3d;
  --text-sub: #5e6d82;
  --text-muted: #8492a6;
  --bg-page: #ffffff;
  --bg-gray: #f5f7fa;
  --border: #e5e9f2;
  --radius: 12px;
  --shadow: 0 6px 24px rgba(15, 43, 96, 0.08);
}

html { scroll-behavior: smooth; }

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

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

img { max-width: 100%; }

.container { width: 100%; max-width: 1120px; margin: 0 auto; padding: 0 24px; }

/* ---------- 顶部导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.brand { display: flex; align-items: center; gap: 10px; }
.brand img { width: 36px; height: 36px; border-radius: 8px; }
.brand .brand-name { font-size: 20px; font-weight: 700; color: var(--text-main); }
.brand .brand-sub { font-size: 12px; color: var(--text-muted); display: block; line-height: 1.2; }

.main-nav { display: flex; align-items: center; gap: 8px; }
.main-nav a {
  padding: 8px 16px;
  font-size: 15px;
  color: var(--text-sub);
  border-radius: 8px;
  transition: all 0.2s ease;
}
.main-nav a:hover { color: var(--primary); background: var(--primary-light); }
.main-nav a.active { color: #fff; background: var(--primary); }

.menu-toggle { display: none; }

/* ---------- 页面横幅 ---------- */
.page-banner {
  background: linear-gradient(135deg, #0b6cff 0%, #0a4bb5 100%);
  color: #fff;
  padding: 56px 0;
  text-align: center;
}
.page-banner h1 { font-size: 32px; margin-bottom: 12px; }
.page-banner p { font-size: 16px; opacity: 0.9; }

/* ---------- 首页 Hero ---------- */
.hero {
  background: linear-gradient(160deg, #f2f7ff 0%, #ffffff 60%);
  overflow: hidden;
}
.hero .container {
  display: flex;
  align-items: center;
  gap: 60px;
  padding-top: 80px;
  padding-bottom: 80px;
}
.hero-text { flex: 1; min-width: 0; }
.hero-badge {
  display: inline-block;
  padding: 4px 14px;
  font-size: 13px;
  color: var(--primary);
  background: var(--primary-light);
  border: 1px solid #c7dcff;
  border-radius: 999px;
  margin-bottom: 20px;
}
.hero-text h1 { font-size: 44px; line-height: 1.25; margin-bottom: 18px; }
.hero-text h1 .highlight { color: var(--primary); }
.hero-text .lead { font-size: 17px; color: var(--text-sub); max-width: 520px; margin-bottom: 30px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; }
.btn {
  display: inline-block;
  padding: 12px 32px;
  font-size: 15px;
  border-radius: 10px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.2s ease;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); color: #fff; }
.btn-outline { background: #fff; color: var(--primary); border-color: #b9d3ff; }
.btn-outline:hover { border-color: var(--primary); color: var(--primary-dark); }

.hero-visual { flex: 0 0 360px; display: flex; justify-content: center; }

/* ---------- 手机模型 ---------- */
.phone {
  width: 280px;
  height: 560px;
  background: #0d1b3e;
  border-radius: 42px;
  padding: 12px;
  box-shadow: 0 24px 60px rgba(11, 46, 106, 0.35);
  position: relative;
}
.phone::before {
  content: "";
  position: absolute;
  top: 18px;
  left: 50%;
  transform: translateX(-50%);
  width: 96px;
  height: 24px;
  background: #0d1b3e;
  border-radius: 12px;
  z-index: 3;
}
.phone-screen {
  width: 100%;
  height: 100%;
  border-radius: 32px;
  overflow: hidden;
  background: #eef4ff;
  position: relative;
}
.phone-screen svg { display: block; width: 100%; height: 100%; object-fit: cover; }

.phone-sm { width: 220px; height: 440px; border-radius: 34px; padding: 10px; }
.phone-sm .phone-screen { border-radius: 26px; }
.phone-sm::before { width: 72px; height: 18px; top: 14px; border-radius: 10px; }

/* ---------- 通用区块 ---------- */
.section { padding: 80px 0; }
.section-gray { background: var(--bg-gray); }
.section-head { text-align: center; max-width: 640px; margin: 0 auto 56px; }
.section-head .eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 4px;
  color: var(--primary);
  margin-bottom: 10px;
}
.section-head h2 { font-size: 32px; margin-bottom: 14px; }
.section-head p { color: var(--text-sub); font-size: 16px; }

/* ---------- 功能卡片 ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.feature-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
  transition: all 0.25s ease;
}
.feature-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-4px);
  border-color: #c7dcff;
}
.feature-icon {
  width: 52px;
  height: 52px;
  border-radius: 12px;
  background: var(--primary-light);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}
.feature-icon svg { width: 26px; height: 26px; }
.feature-card h3 { font-size: 19px; margin-bottom: 10px; }
.feature-card p { font-size: 14.5px; color: var(--text-sub); }

/* ---------- 应用截图展示 ---------- */
.shots {
  display: flex;
  justify-content: center;
  gap: 40px;
  flex-wrap: wrap;
}
.shot { text-align: center; }
.shot .caption { margin-top: 20px; font-size: 15px; font-weight: 600; color: var(--text-main); }
.shot .caption-sub { font-size: 13px; color: var(--text-muted); }

/* ---------- 应用介绍 / 关于 ---------- */
.intro-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}
.intro-item {
  display: flex;
  gap: 16px;
  padding: 24px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.intro-item .num {
  flex: 0 0 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  font-size: 18px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}
.intro-item h3 { font-size: 17px; margin-bottom: 6px; }
.intro-item p { font-size: 14px; color: var(--text-sub); }

.about-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 48px;
  align-items: center;
}
.about-grid h2 { font-size: 30px; margin-bottom: 18px; }
.about-grid p { color: var(--text-sub); margin-bottom: 14px; font-size: 15.5px; }
.spec-table { width: 100%; border-collapse: collapse; background: #fff; border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); }
.spec-table th, .spec-table td {
  padding: 14px 20px;
  font-size: 14.5px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}
.spec-table th { width: 130px; color: var(--text-muted); font-weight: 500; background: #fafbfd; }
.spec-table tr:last-child td { border-bottom: none; }

/* ---------- 正文文档页 ---------- */
.doc { padding: 64px 0 80px; }
.doc-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 48px 56px;
}
.doc-meta { color: var(--text-muted); font-size: 14px; margin-bottom: 28px; }
.doc-meta span { margin-right: 20px; }
.doc h2 {
  font-size: 21px;
  margin: 34px 0 14px;
  padding-left: 12px;
  border-left: 4px solid var(--primary);
}
.doc h3 { font-size: 17px; margin: 22px 0 10px; }
.doc p { margin-bottom: 12px; font-size: 15px; color: #3c4a5e; text-align: justify; }
.doc ul, .doc ol { margin: 0 0 12px 22px; }
.doc li { font-size: 15px; color: #3c4a5e; margin-bottom: 6px; }
.doc table { width: 100%; border-collapse: collapse; margin: 14px 0 20px; }
.doc table th, .doc table td {
  border: 1px solid var(--border);
  padding: 10px 14px;
  font-size: 14px;
  text-align: left;
}
.doc table th { background: #f5f8fd; }

/* ---------- 联系页 ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 48px;
}
.contact-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
  text-align: center;
}
.contact-card .contact-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 16px;
  border-radius: 50%;
  background: var(--primary-light);
  display: flex;
  align-items: center;
  justify-content: center;
}
.contact-card .contact-icon svg { width: 26px; height: 26px; }
.contact-card h3 { font-size: 17px; margin-bottom: 8px; }
.contact-card p { font-size: 14px; color: var(--text-sub); }
.contact-card .contact-value { margin-top: 10px; font-size: 16px; font-weight: 600; color: var(--text-main); word-break: break-all; }

.contact-note {
  background: #f5f8fd;
  border: 1px dashed #c7dcff;
  border-radius: var(--radius);
  padding: 24px 28px;
  color: var(--text-sub);
  font-size: 14.5px;
}

/* ---------- 页脚 ---------- */
.site-footer { background: #101c33; color: #a6b4cc; padding: 56px 0 0; font-size: 14px; }
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.4fr;
  gap: 40px;
  padding-bottom: 40px;
}
.footer-brand { display: flex; align-items: center; gap: 10px; margin-bottom: 16px; }
.footer-brand img { width: 34px; height: 34px; border-radius: 8px; }
.footer-brand span { color: #fff; font-size: 18px; font-weight: 700; }
.site-footer p { margin-bottom: 10px; line-height: 1.8; }
.site-footer h4 { color: #fff; font-size: 15px; margin-bottom: 16px; }
.footer-links a { display: block; color: #a6b4cc; margin-bottom: 10px; }
.footer-links a:hover { color: #fff; }
.footer-contact li { list-style: none; margin-bottom: 10px; display: flex; gap: 8px; align-items: flex-start; }
.footer-contact .li-icon { flex: 0 0 18px; margin-top: 4px; }
.footer-contact .li-icon svg { width: 16px; height: 16px; }
.footer-bottom {
  border-top: 1px solid #22314e;
  padding: 22px 0;
  text-align: center;
  color: #8494ae;
  font-size: 13px;
}
.footer-bottom a { color: #8494ae; }
.footer-bottom a:hover { color: #fff; }
.footer-bottom .sep { margin: 0 10px; color: #3a4a6b; }

/* ---------- 响应式 ---------- */
@media (max-width: 960px) {
  .hero .container { flex-direction: column; gap: 48px; padding-top: 56px; padding-bottom: 56px; }
  .hero-text h1 { font-size: 34px; }
  .hero-visual { flex: none; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .intro-grid { grid-template-columns: 1fr; }
  .about-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .doc-card { padding: 32px 24px; }
}

@media (max-width: 640px) {
  .main-nav {
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    background: #fff;
    border-bottom: 1px solid var(--border);
    padding: 8px 16px 16px;
    gap: 4px;
    display: none;
    box-shadow: 0 12px 24px rgba(15, 43, 96, 0.1);
  }
  .main-nav.open { display: flex; }
  .main-nav a { padding: 12px 16px; }
  .menu-toggle {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 40px;
    height: 40px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
  }
  .menu-toggle span { display: block; height: 2px; background: var(--text-main); border-radius: 2px; }
  .section { padding: 56px 0; }
  .section-head h2 { font-size: 26px; }
  .feature-grid { grid-template-columns: 1fr; }
  .shots { gap: 32px; }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .page-banner h1 { font-size: 26px; }
}